Package 'metagenomeSeq'

Title: Statistical analysis for sparse high-throughput sequencing
Description: metagenomeSeq is designed to determine features (be it Operational Taxanomic Unit (OTU), species, etc.) that are differentially abundant between two or more groups of multiple samples. metagenomeSeq is designed to address the effects of both normalization and under-sampling of microbial communities on disease association detection and the testing of feature correlations.
Authors: Joseph Nathaniel Paulson, Nathan D. Olson, Domenick J. Braccia, Justin Wagner, Hisham Talukder, Mihai Pop, Hector Corrada Bravo
Maintainer: Joseph N. Paulson <[email protected]>
License: Artistic-2.0
Version: 1.49.0
Built: 2024-11-07 06:00:15 UTC
Source: https://github.com/bioc/metagenomeSeq

Help Index


Statistical analysis for sparse high-throughput sequencing

Description

metagenomeSeq is designed to determine features (be it Operational Taxanomic Unit (OTU), species, etc.) that are differentially abundant between two or more groups of multiple samples. metagenomeSeq is designed to address the effects of both normalization and under-sampling of microbial communities on disease association detection and the testing of feature correlations.

A user's guide is available, and can be opened by typing vignette("metagenomeSeq")

The metagenomeSeq package implements novel normalization and statistical methodology in the following papers.

Author(s)

Paulson, JN <[email protected]>; Pop, M; Corrada Bravo, H

References

Paulson, Joseph N., O. Colin Stine, Hector Corrada Bravo, and Mihai Pop. "Differential abundance analysis for microbial marker-gene surveys." Nature methods (2013).


Aggregates a MRexperiment object or counts matrix to by a factor.

Description

Using the phenoData information in the MRexperiment, calling aggregateBySample on a MRexperiment and a particular phenoData column (i.e. 'diet') will aggregate counts using the aggfun function (default rowMeans). Possible aggfun alternatives include rowMeans and rowMedians.

Usage

aggregateBySample(obj, fct, aggfun = rowMeans, out = "MRexperiment")

aggSamp(obj, fct, aggfun = rowMeans, out = "MRexperiment")

Arguments

obj

A MRexperiment object or count matrix.

fct

phenoData column name from the MRexperiment object or if count matrix object a vector of labels.

aggfun

Aggregation function.

out

Either 'MRexperiment' or 'matrix'

Value

An aggregated count matrix or MRexperiment object where the new pData is a vector of 'fct' levels.

Examples

data(mouseData)
aggregateBySample(mouseData[1:100,],fct="diet",aggfun=rowSums)
# not run
# aggregateBySample(mouseData,fct="diet",aggfun=matrixStats::rowMedians)
# aggSamp(mouseData,fct='diet',aggfun=rowMaxs)

Aggregates a MRexperiment object or counts matrix to a particular level.

Description

Using the featureData information in the MRexperiment, calling aggregateByTaxonomy on a MRexperiment and a particular featureData column (i.e. 'genus') will aggregate counts to the desired level using the aggfun function (default colSums). Possible aggfun alternatives include colMeans and colMedians.

Usage

aggregateByTaxonomy(
  obj,
  lvl,
  alternate = FALSE,
  norm = FALSE,
  log = FALSE,
  aggfun = colSums,
  sl = 1000,
  featureOrder = NULL,
  returnFullHierarchy = TRUE,
  out = "MRexperiment"
)

aggTax(
  obj,
  lvl,
  alternate = FALSE,
  norm = FALSE,
  log = FALSE,
  aggfun = colSums,
  sl = 1000,
  featureOrder = NULL,
  returnFullHierarchy = TRUE,
  out = "MRexperiment"
)

Arguments

obj

A MRexperiment object or count matrix.

lvl

featureData column name from the MRexperiment object or if count matrix object a vector of labels.

alternate

Use the rowname for undefined OTUs instead of aggregating to "no_match".

norm

Whether to aggregate normalized counts or not.

log

Whether or not to log2 transform the counts - if MRexperiment object.

aggfun

Aggregation function.

sl

scaling value, default is 1000.

featureOrder

Hierarchy of levels in taxonomy as fData colnames

returnFullHierarchy

Boolean value to indicate return single column of fData or all columns of hierarchy

out

Either 'MRexperiment' or 'matrix'

Value

An aggregated count matrix.

Examples

data(mouseData)
aggregateByTaxonomy(mouseData[1:100,],lvl="class",norm=TRUE,aggfun=colSums)
# not run
# aggregateByTaxonomy(mouseData,lvl="class",norm=TRUE,aggfun=colMedians)
# aggTax(mouseData,lvl='phylum',norm=FALSE,aggfun=colSums)

Biom to MRexperiment objects

Description

Wrapper to convert biom files to MRexperiment objects.

Usage

biom2MRexperiment(obj)

Arguments

obj

The biom object file.

Value

A MRexperiment object.

See Also

loadMeta loadPhenoData newMRexperiment loadBiom

Examples

library(biomformat)
rich_dense_file = system.file("extdata", "rich_dense_otu_table.biom", package = "biomformat")
x = biomformat::read_biom(rich_dense_file)
biom2MRexperiment(x)

Cumulative sum scaling (css) normalization factors

Description

Return a vector of the the sum up to and including a quantile.

Usage

calcNormFactors(obj, p = cumNormStatFast(obj))

Arguments

obj

An MRexperiment object or matrix.

p

The pth quantile.

Value

Vector of the sum up to and including a sample's pth quantile.

See Also

fitZig cumNormStatFast cumNorm

Examples

data(mouseData)
head(calcNormFactors(mouseData))

Positive component

Description

Fit the positive (log-normal) component

Usage

calcPosComponent(mat, mod, weights)

Arguments

mat

A matrix of normalized counts

mod

A model matrix

weights

Weight matrix for samples and counts

See Also

fitZeroLogNormal fitFeatureModel


Calculate shrinkage parameters

Description

Calculate the shrunken variances and variance of parameters of interest across features.

Usage

calcShrinkParameters(fit, coef, mins2, exclude = NULL)

Arguments

fit

A matrix of fits as outputted by calcZeroComponent or calcPosComponent

coef

Coefficient of interest

mins2

minimum variance estimate

exclude

Vector of features to exclude when shrinking

See Also

fitZeroLogNormal fitFeatureModel


Calculate the zero-inflated log-normal statistic's standard error

Description

Calculat the se for the model. Code modified from "Adjusting for covariates in zero-inflated gamma and zero-inflated log-normal models for semicontinuous data", ED Mills

Usage

calcStandardError(mod, fitln, fitzero, coef = 2, exclude = NULL)

Arguments

mod

The zero component model matrix

fitln

A matrix with parameters from the log-normal fit

fitzero

A matrix with parameters from the logistic fit

coef

Coefficient of interest

exclude

List of features to exclude

See Also

fitZeroLogNormal fitFeatureModel


Estimated effective samples per feature

Description

Calculates the number of estimated effective samples per feature from the output of a fitZig run. The estimated effective samples per feature is calculated as the sum_1^n (n = number of samples) 1-z_i where z_i is the posterior probability a feature belongs to the technical distribution.

Usage

calculateEffectiveSamples(obj)

Arguments

obj

The output of fitZig run on a MRexperiment object.

Value

A list of the estimated effective samples per feature.

See Also

fitZig MRcoefs MRfulltable


Calculate the zero-inflated component's adjustment factor

Description

Calculate the log ratio of average marginal probabilities for each sample having a positive count. This becomes the adjustment factor for the log fold change.

Usage

calcZeroAdjustment(fitln, fitzero, mod, coef, exclude = NULL)

Arguments

fitln

A matrix with parameters from the log-normal fit

fitzero

A matrix with parameters from the logistic fit

mod

The zero component model matrix

coef

Coefficient of interest

exclude

List of features to exclude

See Also

fitZeroLogNormal fitFeatureModel


Zero component

Description

Fit the zero (logisitic) component

Usage

calcZeroComponent(mat, mod, weights)

Arguments

mat

A matrix of normalized counts

mod

A model matrix

weights

Weight matrix for samples and counts

See Also

fitZeroLogNormal fitFeatureModel


Calculate the correct indices for the output of correlationTest

Description

Consider the upper triangular portion of a matrix of size nxn. Results from the correlationTest are output as the combination of two vectors, correlation statistic and p-values. The order of the output is 1vs2, 1vs3, 1vs4, etc. The correctIndices returns the correct indices to fill a correlation matrix or correlation-pvalue matrix.

Usage

correctIndices(n)

Arguments

n

The number of features compared by correlationTest (nrow(mat)).

Value

A vector of the indices for an upper triangular matrix.

See Also

correlationTest

Examples

data(mouseData)
mat = MRcounts(mouseData)[55:60,]
cors = correlationTest(mat)
ind  = correctIndices(nrow(mat))

cormat = as.matrix(dist(mat))
cormat[cormat>0] = 0
cormat[upper.tri(cormat)][ind] = cors[,1]
table(cormat[1,-1] - cors[1:5,1])

Correlation of each row of a matrix or MRexperiment object

Description

Calculates the (pairwise) correlation statistics and associated p-values of a matrix or the correlation of each row with a vector.

Usage

correlationTest(
  obj,
  y = NULL,
  method = "pearson",
  alternative = "two.sided",
  norm = TRUE,
  log = TRUE,
  cores = 1,
  override = FALSE,
  ...
)

Arguments

obj

A MRexperiment object or count matrix.

y

Vector of length ncol(obj) to compare to.

method

One of 'pearson','spearman', or 'kendall'.

alternative

Indicates the alternative hypothesis and must be one of 'two.sided', 'greater' (positive) or 'less'(negative). You can specify just the initial letter.

norm

Whether to aggregate normalized counts or not - if MRexperiment object.

log

Whether or not to log2 transform the counts - if MRexperiment object.

cores

Number of cores to use.

override

If the number of rows to test is over a thousand the test will not commence (unless override==TRUE).

...

Extra parameters for mclapply.

Value

A matrix of size choose(number of rows, 2) by 2. The first column corresponds to the correlation value. The second column the p-value.

See Also

correctIndices

Examples

# Pairwise correlation of raw counts
data(mouseData)
cors = correlationTest(mouseData[1:10,],norm=FALSE,log=FALSE)
head(cors)

mat = MRcounts(mouseData)[1:10,]
cormat = as.matrix(dist(mat)) # Creating a matrix
cormat[cormat>0] = 0 # Creating an empty matrix
ind = correctIndices(nrow(mat))
cormat[upper.tri(cormat)][ind] = cors[,1] 
table(cormat[1,-1] - cors[1:9,1])

# Correlation of raw counts with a vector (library size in this case)
data(mouseData)
cors = correlationTest(mouseData[1:10,],libSize(mouseData),norm=FALSE,log=FALSE)
head(cors)

Cumulative sum scaling normalization

Description

Calculates each column's quantile and calculates the sum up to and including that quantile.

Usage

cumNorm(obj, p = cumNormStatFast(obj))

Arguments

obj

An MRexperiment object.

p

The pth quantile.

Value

Object with the normalization factors stored as a vector of the sum up to and including a sample's pth quantile.

See Also

fitZig cumNormStat

Examples

data(mouseData)
mouseData <- cumNorm(mouseData)
head(normFactors(mouseData))

Cumulative sum scaling factors.

Description

Calculates each column's quantile and calculates the sum up to and including that quantile.

Usage

cumNormMat(obj, p = cumNormStatFast(obj), sl = 1000)

Arguments

obj

A matrix or MRexperiment object.

p

The pth quantile.

sl

The value to scale by (default=1000).

Value

Returns a matrix normalized by scaling counts up to and including the pth quantile.

See Also

fitZig cumNorm

Examples

data(mouseData)
head(cumNormMat(mouseData))

Cumulative sum scaling percentile selection

Description

Calculates the percentile for which to sum counts up to and scale by. cumNormStat might be deprecated one day. Deviates from methods in Nature Methods paper by making use row means for generating reference.

Usage

cumNormStat(obj, qFlag = TRUE, pFlag = FALSE, rel = 0.1, ...)

Arguments

obj

A matrix or MRexperiment object.

qFlag

Flag to either calculate the proper percentile using R's step-wise quantile function or approximate function.

pFlag

Plot the relative difference of the median deviance from the reference.

rel

Cutoff for the relative difference from one median difference from the reference to the next

...

Applicable if pFlag == TRUE. Additional plotting parameters.

Value

Percentile for which to scale data

See Also

fitZig cumNorm cumNormStatFast

Examples

data(mouseData)
p = round(cumNormStat(mouseData,pFlag=FALSE),digits=2)

Cumulative sum scaling percentile selection

Description

Calculates the percentile for which to sum counts up to and scale by. Faster version than available in cumNormStat. Deviates from methods described in Nature Methods by making use of ro means for reference.

Usage

cumNormStatFast(obj, pFlag = FALSE, rel = 0.1, ...)

Arguments

obj

A matrix or MRexperiment object.

pFlag

Plot the median difference quantiles.

rel

Cutoff for the relative difference from one median difference from the reference to the next.

...

Applicable if pFlag == TRUE. Additional plotting parameters.

Value

Percentile for which to scale data

See Also

fitZig cumNorm cumNormStat

Examples

data(mouseData)
p = round(cumNormStatFast(mouseData,pFlag=FALSE),digits=2)

Compute the Maximization step calculation for features still active.

Description

Maximization step is solved by weighted least squares. The function also computes counts residuals.

Usage

doCountMStep(z, y, mmCount, stillActive, fit2 = NULL, dfMethod = "modified")

Arguments

z

Matrix (m x n) of estimate responsibilities (probabilities that a count comes from a spike distribution at 0).

y

Matrix (m x n) of count observations.

mmCount

Model matrix for the count distribution.

stillActive

Boolean vector of size M, indicating whether a feature converged or not.

fit2

Previous fit of the count model.

dfMethod

Either 'default' or 'modified' (by responsibilities)

Details

Maximum-likelihood estimates are approximated using the EM algorithm where we treat mixture membership $delta_ij$ = 1 if $y_ij$ is generated from the zero point mass as latent indicator variables. The density is defined as $f_zig(y_ij = pi_j(S_j)*f_0(y_ij) +(1-pi_j (S_j)) * f_count(y_ij;mu_i,sigma_i^2)$. The log-likelihood in this extended model is $(1-delta_ij) log f_count(y;mu_i,sigma_i^2 )+delta_ij log pi_j(s_j)+(1-delta_ij)log (1-pi_j (s_j))$. The responsibilities are defined as $z_ij = pr(delta_ij=1 | data)$.

Value

Update matrix (m x n) of estimate responsibilities (probabilities that a count comes from a spike distribution at 0).

See Also

fitZig


Compute the Expectation step.

Description

Estimates the responsibilities $z_ij = fracpi_j cdot I_0(y_ijpi_j cdot I_0(y_ij + (1-pi_j) cdot f_count(y_ij

Usage

doEStep(countResiduals, zeroResiduals, zeroIndices)

Arguments

countResiduals

Residuals from the count model.

zeroResiduals

Residuals from the zero model.

zeroIndices

Index (matrix m x n) of counts that are zero/non-zero.

Details

Maximum-likelihood estimates are approximated using the EM algorithm where we treat mixture membership $delta_ij$ = 1 if $y_ij$ is generated from the zero point mass as latent indicator variables. The density is defined as $f_zig(y_ij = pi_j(S_j) cdot f_0(y_ij) +(1-pi_j (S_j))cdot f_count(y_ij;mu_i,sigma_i^2)$. The log-likelihood in this extended model is $(1-delta_ij) log f_count(y;mu_i,sigma_i^2 )+delta_ij log pi_j(s_j)+(1-delta_ij)log (1-pi_j (sj))$. The responsibilities are defined as $z_ij = pr(delta_ij=1 | data)$.

Value

Updated matrix (m x n) of estimate responsibilities (probabilities that a count comes from a spike distribution at 0).

See Also

fitZig


Compute the zero Maximization step.

Description

Performs Maximization step calculation for the mixture components. Uses least squares to fit the parameters of the mean of the logistic distribution. $$ pi_j = sum_i^M frac1Mz_ij $$ Maximum-likelihood estimates are approximated using the EM algorithm where we treat mixture membership $delta_ij$ = 1 if $y_ij$ is generated from the zero point mass as latent indicator variables. The density is defined as $f_zig(y_ij = pi_j(S_j) cdot f_0(y_ij) +(1-pi_j (S_j))cdot f_count(y_ij;mu_i,sigma_i^2)$. The log-likelihood in this extended model is $(1-delta_ij) log f_count(y;mu_i,sigma_i^2 )+delta_ij log pi_j(s_j)+(1-delta_ij)log (1-pi_j (sj))$. The responsibilities are defined as $z_ij = pr(delta_ij=1 | data)$.

Usage

doZeroMStep(z, zeroIndices, mmZero)

Arguments

z

Matrix (m x n) of estimate responsibilities (probabilities that a count comes from a spike distribution at 0).

zeroIndices

Index (matrix m x n) of counts that are zero/non-zero.

mmZero

The zero model, the model matrix to account for the change in the number of OTUs observed as a linear effect of the depth of coverage.

Value

List of the zero fit (zero mean model) coefficients, variance - scale parameter (scalar), and normalized residuals of length sum(zeroIndices).

See Also

fitZig


Export the normalized MRexperiment dataset as a matrix.

Description

This function allows the user to take a dataset of counts and output the dataset to the user's workspace as a tab-delimited file, etc.

Usage

exportMat(
  obj,
  log = TRUE,
  norm = TRUE,
  sep = "\t",
  file = "~/Desktop/matrix.tsv"
)

Arguments

obj

A MRexperiment object or count matrix.

log

Whether or not to log transform the counts - if MRexperiment object.

norm

Whether or not to normalize the counts - if MRexperiment object.

sep

Separator for writing out the count matrix.

file

Output file name.

Value

NA

See Also

cumNorm

Examples

data(lungData)
dataDirectory <- system.file("extdata", package="metagenomeSeq")
exportMat(lungData[,1:5],file=file.path(dataDirectory,"tmp.tsv"))
head(read.csv(file=file.path(dataDirectory,"tmp.tsv"),sep="\t"))

Various statistics of the count data.

Description

A matrix of values for each sample. The matrix consists of sample ids, the sample scaling factor, quantile value, the number identified features, and library size (depth of coverage).

Usage

exportStats(obj, p = cumNormStat(obj), file = "~/Desktop/res.stats.tsv")

Arguments

obj

A MRexperiment object with count data.

p

Quantile value to calculate the scaling factor and quantiles for the various samples.

file

Output file name.

Value

None.

See Also

cumNorm quantile

Examples

data(lungData)
dataDirectory <- system.file("extdata", package="metagenomeSeq")
exportStats(lungData[,1:5],file=file.path(dataDirectory,"tmp.tsv"))
head(read.csv(file=file.path(dataDirectory,"tmp.tsv"),sep="\t"))

Access MRexperiment object experiment data

Description

The expSummary vectors represent the column (sample specific) sums of features, i.e. the total number of reads for a sample, libSize and also the normalization factors, normFactor.

Usage

expSummary(obj)

Arguments

obj

a MRexperiment object.

Value

Experiment summary table

Author(s)

Joseph N. Paulson, [email protected]

Examples

data(mouseData)
expSummary(mouseData)

Extract the essentials of an MRexperiment.

Description

Extract the essentials of an MRexperiment.

Usage

extractMR(obj)

Arguments

obj

MRexperiment-class object.

Value

A list containing:

  • counts : Count data

  • librarySize : The column sums / library size / sequencing depth

  • normFactors : The normalization scaling factors

  • pheno : phenotype table

  • feat : feature table

Examples

data(mouseData)
head(metagenomeSeq:::extractMR(mouseData))

Filter datasets according to no. features present in features with at least a certain depth.

Description

Filter the data based on the number of present features after filtering samples by depth of coverage. There are many ways to filter the object, this is just one way.

Usage

filterData(obj, present = 1, depth = 1000)

Arguments

obj

A MRexperiment object or count matrix.

present

Features with at least 'present' postive samples.

depth

Sampls with at least this much depth of coverage

Value

A MRexperiment object.

Examples

data(mouseData)
filterData(mouseData)

Wrapper to calculate Discovery Odds Ratios on feature values.

Description

This function returns a data frame of p-values, odds ratios, lower and upper confidence limits for every row of a matrix. The discovery odds ratio is calculated as using Fisher's exact test on actual counts. The test's hypothesis is whether or not the discovery of counts for a feature (of all counts) is found in greater proportion in a particular group.

Usage

fitDO(obj, cl, norm = TRUE, log = TRUE, adjust.method = "fdr", cores = 1, ...)

Arguments

obj

A MRexperiment object with a count matrix, or a simple count matrix.

cl

Group comparison

norm

Whether or not to normalize the counts - if MRexperiment object.

log

Whether or not to log2 transform the counts - if MRexperiment object.

adjust.method

Method to adjust p-values by. Default is "FDR". Options include "holm", "hochberg", "hommel", "bonferroni", "BH", "BY", "fdr", "none". See p.adjust for more details.

cores

Number of cores to use.

...

Extra options for makeCluster

Value

Matrix of odds ratios, p-values, lower and upper confidence intervals

See Also

cumNorm fitZig fitPA fitMeta

Examples

data(lungData)
k = grep("Extraction.Control",pData(lungData)$SampleType)
lungTrim = lungData[,-k]
lungTrim = lungTrim[-which(rowSums(MRcounts(lungTrim)>0)<20),]
res = fitDO(lungTrim,pData(lungTrim)$SmokingStatus);
head(res)

Computes differential abundance analysis using a zero-inflated log-normal model

Description

Wrapper to actually run zero-inflated log-normal model given a MRexperiment object and model matrix. User can decide to shrink parameter estimates.

Usage

fitFeatureModel(obj, mod, coef = 2, B = 1, szero = FALSE, spos = TRUE)

Arguments

obj

A MRexperiment object with count data.

mod

The model for the count distribution.

coef

Coefficient of interest to grab log fold-changes.

B

Number of bootstraps to perform if >1. If >1 performs permutation test.

szero

TRUE/FALSE, shrink zero component parameters.

spos

TRUE/FALSE, shrink positive component parameters.

Value

A list of objects including:

  • call - the call made to fitFeatureModel

  • fitZeroLogNormal - list of parameter estimates for the zero-inflated log normal model

  • design - model matrix

  • taxa - taxa names

  • counts - count matrix

  • pvalues - calculated p-values

  • permuttedfits - permutted z-score estimates under the null

See Also

cumNorm

Examples

data(lungData)
lungData = lungData[,-which(is.na(pData(lungData)$SmokingStatus))]
lungData=filterData(lungData,present=30,depth=1)
lungData <- cumNorm(lungData, p=.5)
s <- normFactors(lungData)
pd <- pData(lungData)
mod <- model.matrix(~1+SmokingStatus, data=pd)
lungres1 = fitFeatureModel(lungData,mod)

Class "fitFeatureModelResults" – a formal class for storing results from a fitFeatureModel call

Description

This class contains all of the same information expected from a fitFeatureModel call, but it is defined in the S4 style as opposed to being stored as a list.

Slots

call

the call made to fitFeatureModel

fitZeroLogNormal

list of parameter estimates for the zero-inflated log normal model

design

model matrix

taxa

taxa names

counts

count matrix

pvalues

calculated p-values

permuttedFits

permutted z-score estimates under the null


Computes a log-normal linear model and permutation based p-values.

Description

Wrapper to perform the permutation test on the t-statistic. This is the original method employed by metastats (for non-sparse large samples). We include CSS normalization though (optional) and log2 transform the data. In this method the null distribution is not assumed to be a t-dist.

Usage

fitLogNormal(obj, mod, useCSSoffset = TRUE, B = 1000, coef = 2, sl = 1000)

Arguments

obj

A MRexperiment object with count data.

mod

The model for the count distribution.

useCSSoffset

Boolean, whether to include the default scaling parameters in the model or not.

B

Number of permutations.

coef

The coefficient of interest.

sl

The value to scale by (default=1000).

Value

Call made, fit object from lmFit, t-statistics and p-values for each feature.

Examples

# This is a simple demonstration
data(lungData)
k = grep("Extraction.Control",pData(lungData)$SampleType)
lungTrim = lungData[,-k]
k = which(rowSums(MRcounts(lungTrim)>0)<30)
lungTrim = cumNorm(lungTrim)
lungTrim = lungTrim[-k,]
smokingStatus = pData(lungTrim)$SmokingStatus
mod = model.matrix(~smokingStatus)
fit = fitLogNormal(obj = lungTrim,mod=mod,B=1)

Discover differentially abundant time intervals for all bacteria

Description

Calculate time intervals of significant differential abundance over all bacteria of a particularly specified level (lvl). If not lvl is specified, all OTUs are analyzed. Warning, function can take a while

Usage

fitMultipleTimeSeries(obj, lvl = NULL, B = 1, featureOrder = NULL, ...)

Arguments

obj

metagenomeSeq MRexperiment-class object.

lvl

Vector or name of column in featureData of MRexperiment-class object for aggregating counts (if not OTU level).

B

Number of permutations to perform.

featureOrder

Hierarchy of levels in taxonomy as fData colnames

...

Options for fitTimeSeries, except feature.

Value

List of lists of matrices of time point intervals of interest, Difference in abundance area and p-value, fit, area permutations.

A list of lists for which each includes:

  • timeIntervals - Matrix of time point intervals of interest, area of differential abundance, and pvalue.

  • data - Data frame of abundance, class indicator, time, and id input.

  • fit - Data frame of fitted values of the difference in abundance, standard error estimates and timepoints interpolated over.

  • perm - Differential abundance area estimates for each permutation.

  • call - Function call.

See Also

cumNorm fitSSTimeSeries fitTimeSeries

Examples

data(mouseData)
res = fitMultipleTimeSeries(obj=mouseData,lvl='phylum',class="status",
          id="mouseID",time="relativeTime",B=1)

Wrapper to run fisher's test on presence/absence of a feature.

Description

This function returns a data frame of p-values, odds ratios, lower and upper confidence limits for every row of a matrix.

Usage

fitPA(obj, cl, thres = 0, adjust.method = "fdr", cores = 1, ...)

Arguments

obj

A MRexperiment object with a count matrix, or a simple count matrix.

cl

Group comparison

thres

Threshold for defining presence/absence.

adjust.method

Method to adjust p-values by. Default is "FDR". Options include "holm", "hochberg", "hommel", "bonferroni", "BH", "BY", "fdr", "none". See p.adjust for more details.

cores

Number of cores to use.

...

Extra parameters for makeCluster

Value

Matrix of odds ratios, p-values, lower and upper confidence intervals

See Also

cumNorm fitZig fitDO fitMeta

Examples

data(lungData)
k = grep("Extraction.Control",pData(lungData)$SampleType)
lungTrim = lungData[,-k]
lungTrim = lungTrim[-which(rowSums(MRcounts(lungTrim)>0)<20),]
res = fitPA(lungTrim,pData(lungTrim)$SmokingStatus);
head(res)

Discover differentially abundant time intervals using SS-Anova

Description

Calculate time intervals of interest using SS-Anova fitted models. Fitting is performed uses Smoothing Spline ANOVA (SS-Anova) to find interesting intervals of time. Given observations at different time points for two groups, fitSSTimeSeries calculates a function that models the difference in abundance between two groups across all time. Using permutations we estimate a null distribution of areas for the time intervals of interest and report significant intervals of time. Use of the function for analyses should cite: "Finding regions of interest in high throughput genomics data using smoothing splines" Talukder H, Paulson JN, Bravo HC. (In preparation)

Usage

fitSSTimeSeries(
  obj,
  formula,
  feature,
  class,
  time,
  id,
  lvl = NULL,
  include = c("class", "time:class"),
  C = 0,
  B = 1000,
  norm = TRUE,
  log = TRUE,
  sl = 1000,
  featureOrder = NULL,
  ...
)

Arguments

obj

metagenomeSeq MRexperiment-class object.

formula

Formula for ssanova. Of the form: abundance ~ ... where ... includes any pData slot value.

feature

Name or row of feature of interest.

class

Name of column in phenoData of MRexperiment-class object for class memberhip.

time

Name of column in phenoData of MRexperiment-class object for relative time.

id

Name of column in phenoData of MRexperiment-class object for sample id.

lvl

Vector or name of column in featureData of MRexperiment-class object for aggregating counts (if not OTU level).

include

Parameters to include in prediction.

C

Value for which difference function has to be larger or smaller than (default 0).

B

Number of permutations to perform

norm

When aggregating counts to normalize or not.

log

Log2 transform.

sl

Scaling value.

featureOrder

Hierarchy of levels in taxonomy as fData colnames

...

Options for ssanova

Value

List of matrix of time point intervals of interest, Difference in abundance area and p-value, fit, area permutations, and call.

A list of objects including:

  • timeIntervals - Matrix of time point intervals of interest, area of differential abundance, and pvalue.

  • data - Data frame of abundance, class indicator, time, and id input.

  • fit - Data frame of fitted values of the difference in abundance, standard error estimates and timepoints interpolated over.

  • perm - Differential abundance area estimates for each permutation.

  • call - Function call.

See Also

cumNorm ssFit ssIntervalCandidate ssPerm ssPermAnalysis plotTimeSeries

Examples

data(mouseData)
res = fitSSTimeSeries(obj=mouseData,feature="Actinobacteria",
   class="status",id="mouseID",time="relativeTime",lvl='class',B=2)

Discover differentially abundant time intervals

Description

Calculate time intervals of significant differential abundance. Currently only one method is implemented (ssanova). fitSSTimeSeries is called with method="ssanova".

Usage

fitTimeSeries(
  obj,
  formula,
  feature,
  class,
  time,
  id,
  method = c("ssanova"),
  lvl = NULL,
  include = c("class", "time:class"),
  C = 0,
  B = 1000,
  norm = TRUE,
  log = TRUE,
  sl = 1000,
  featureOrder = NULL,
  ...
)

Arguments

obj

metagenomeSeq MRexperiment-class object.

formula

Formula for ssanova. Of the form: abundance ~ ... where ... includes any pData slot value.

feature

Name or row of feature of interest.

class

Name of column in phenoData of MRexperiment-class object for class memberhip.

time

Name of column in phenoData of MRexperiment-class object for relative time.

id

Name of column in phenoData of MRexperiment-class object for sample id.

method

Method to estimate time intervals of differentially abundant bacteria (only ssanova method implemented currently).

lvl

Vector or name of column in featureData of MRexperiment-class object for aggregating counts (if not OTU level).

include

Parameters to include in prediction.

C

Value for which difference function has to be larger or smaller than (default 0).

B

Number of permutations to perform.

norm

When aggregating counts to normalize or not.

log

Log2 transform.

sl

Scaling value.

featureOrder

Hierarchy of levels in taxonomy as fData colnames

...

Options for ssanova

Value

List of matrix of time point intervals of interest, Difference in abundance area and p-value, fit, area permutations, and call.

A list of objects including:

  • timeIntervals - Matrix of time point intervals of interest, area of differential abundance, and pvalue.

  • data - Data frame of abundance, class indicator, time, and id input.

  • fit - Data frame of fitted values of the difference in abundance, standard error estimates and timepoints interpolated over.

  • perm - Differential abundance area estimates for each permutation.

  • call - Function call.

See Also

cumNorm fitSSTimeSeries plotTimeSeries

Examples

data(mouseData)
res = fitTimeSeries(obj=mouseData,feature="Actinobacteria",
   class="status",id="mouseID",time="relativeTime",lvl='class',B=2)

Compute the log fold-change estimates for the zero-inflated log-normal model

Description

Run the zero-inflated log-normal model given a MRexperiment object and model matrix. Not for the average user, assumes structure of the model matrix.

Usage

fitZeroLogNormal(obj, mod, coef = 2, szero = TRUE, spos = TRUE)

Arguments

obj

A MRexperiment object with count data.

mod

The model for the count distribution.

coef

Coefficient of interest to grab log fold-changes.

szero

TRUE/FALSE, shrink zero component parameters.

spos

TRUE/FALSE, shrink positive component parameters.

Value

A list of objects including:

  • logFC - the log fold-change estimates

  • adjFactor - the adjustment factor based on the zero component

  • se - standard error estimates

  • fitln - parameters from the log-normal fit

  • fitzero - parameters from the logistic fit

  • zeroRidge - output from the ridge regression

  • posRidge - output from the ridge regression

  • tauPos - estimated tau^2 for positive component

  • tauZero - estimated tau^2 for zero component

  • exclude - features to exclude for various reasons, e.g. all zeros

  • zeroExclude - features to exclude for various reasons, e.g. all zeros

See Also

cumNorm fitFeatureModel


Computes the weighted fold-change estimates and t-statistics.

Description

Wrapper to actually run the Expectation-maximization algorithm and estimate $f_count$ fits. Maximum-likelihood estimates are approximated using the EM algorithm where we treat mixture membership $delta_ij = 1$ if $y_ij$ is generated from the zero point mass as latent indicator variables. The density is defined as $f_zig(y_ij = pi_j(S_j)*f_0(y_ij) +(1-pi_j (S_j)) * f_count(y_ij; mu_i, sigma_i^2)$. The log-likelihood in this extended model is: $(1-delta_ij) log f_count(y;mu_i,sigma_i^2 )+delta_ij log pi_j(s_j)+(1-delta_ij) log (1-pi_j (s_j))$. The responsibilities are defined as $z_ij = pr(delta_ij=1 | data)$.

Usage

fitZig(
  obj,
  mod,
  zeroMod = NULL,
  useCSSoffset = TRUE,
  control = zigControl(),
  useMixedModel = FALSE,
  ...
)

Arguments

obj

A MRexperiment object with count data.

mod

The model for the count distribution.

zeroMod

The zero model, the model to account for the change in the number of OTUs observed as a linear effect of the depth of coverage.

useCSSoffset

Boolean, whether to include the default scaling parameters in the model or not.

control

The settings for fitZig.

useMixedModel

Estimate the correlation between duplicate features or replicates using duplicateCorrelation.

...

Additional parameters for duplicateCorrelation.

Value

A list of objects including:

  • call - the call made to fitZig

  • fit - 'MLArrayLM' Limma object of the weighted fit

  • countResiduals - standardized residuals of the fit

  • z - matrix of the posterior probabilities

  • eb - output of eBayes, moderated t-statistics, moderated F-statistics, etc

  • taxa - vector of the taxa names

  • counts - the original count matrix input

  • zeroMod - the zero model matrix

  • zeroCoef - the zero model fitted results

  • stillActive - convergence

  • stillActiveNLL - nll at convergence

  • dupcor - correlation of duplicates

See Also

cumNorm zigControl

Examples

# This is a simple demonstration 
data(lungData)
k = grep("Extraction.Control",pData(lungData)$SampleType)
lungTrim = lungData[,-k]
k = which(rowSums(MRcounts(lungTrim)>0)<30)
lungTrim = cumNorm(lungTrim)
lungTrim = lungTrim[-k,]
smokingStatus = pData(lungTrim)$SmokingStatus
mod = model.matrix(~smokingStatus)
# The maxit is not meant to be 1 - this is for demonstration/speed
settings = zigControl(maxit=1,verbose=FALSE)
fit = fitZig(obj = lungTrim,mod=mod,control=settings)

Class "fitZigResults" – a formal class for storing results from a fitZig call

Description

This class contains all of the same information expected from a fitZig call, but it is defined in the S4 style as opposed to being stored as a list.

Slots

call

the call made to fitZig

fit

'MLArrayLM' Limma object of the weighted fit

countResiduals

standardized residuals of the fit

z

matrix of the posterior probabilities. It is defined as $z_ij = pr(delta_ij=1 | data)$

zUsed

used in getZ

eb

output of eBayes, moderated t-statistics, moderated F-statistics, etc

taxa

vector of the taxa names

counts

the original count matrix input

zeroMod

the zero model matrix

zeroCoef

the zero model fitted results

stillActive

convergence

stillActiveNLL

nll at convergence

dupcor

correlation of duplicates


Compute the value of the count density function from the count model residuals.

Description

Calculate density values from a normal: $f(x) = 1/(sqrt (2 pi ) sigma ) e^-((x - mu )^2/(2 sigma^2))$. Maximum-likelihood estimates are approximated using the EM algorithm where we treat mixture membership $deta_ij$ = 1 if $y_ij$ is generated from the zero point mass as latent indicator variables. The density is defined as $f_zig(y_ij = pi_j(S_j) cdot f_0(y_ij) +(1-pi_j (S_j))cdot f_count(y_ij;mu_i,sigma_i^2)$. The log-likelihood in this extended model is $(1-delta_ij) log f_count(y;mu_i,sigma_i^2 )+delta_ij log pi_j(s_j)+(1-delta_ij)log (1-pi_j (sj))$. The responsibilities are defined as $z_ij = pr(delta_ij=1 | data)$.

Usage

getCountDensity(residuals, log = FALSE)

Arguments

residuals

Residuals from the count model.

log

Whether or not we are calculating from a log-normal distribution.

Value

Density values from the count model residuals.

See Also

fitZig


Calculate the relative difference between iterations of the negative log-likelihoods.

Description

Maximum-likelihood estimates are approximated using the EM algorithm where we treat mixture membership $delta_ij$ = 1 if $y_ij$ is generated from the zero point mass as latent indicator variables. The log-likelihood in this extended model is $(1-delta_ij) log f_count(y;mu_i,sigma_i^2 )+delta_ij log pi_j(s_j)+(1-delta_ij)log (1-pi_j (sj))$. The responsibilities are defined as $z_ij = pr(delta_ij=1 | data)$.

Usage

getEpsilon(nll, nllOld)

Arguments

nll

Vector of size M with the current negative log-likelihoods.

nllOld

Vector of size M with the previous iterations negative log-likelihoods.

Value

Vector of size M of the relative differences between the previous and current iteration nll.

See Also

fitZig


Calculate the negative log-likelihoods for the various features given the residuals.

Description

Maximum-likelihood estimates are approximated using the EM algorithm where we treat mixture membership $delta_ij$ = 1 if $y_ij$ is generated from the zero point mass as latent indicator variables. The log-likelihood in this extended model is $(1-delta_ij) log f_count(y;mu_i,sigma_i^2 )+delta_ij log pi_j(s_j)+(1-delta_ij)log (1-pi_j (sj))$. The responsibilities are defined as $z_ij = pr(delta_ij=1 | data and current values)$.

Usage

getNegativeLogLikelihoods(z, countResiduals, zeroResiduals)

Arguments

z

Matrix (m x n) of estimate responsibilities (probabilities that a count comes from a spike distribution at 0).

countResiduals

Residuals from the count model.

zeroResiduals

Residuals from the zero model.

Value

Vector of size M of the negative log-likelihoods for the various features.

See Also

fitZig


Calculate the mixture proportions from the zero model / spike mass model residuals.

Description

F(x) = 1 / (1 + exp(-(x-m)/s)) (the CDF of the logistic distribution). Provides the probability that a real-valued random variable X with a given probability distribution will be found at a value less than or equal to x. The output are the mixture proportions for the samples given the residuals from the zero model.

Usage

getPi(residuals)

Arguments

residuals

Residuals from the zero model.

Value

Mixture proportions for each sample.

See Also

fitZig


Calculate the current Z estimate responsibilities (posterior probabilities)

Description

Calculate the current Z estimate responsibilities (posterior probabilities)

Usage

getZ(z, zUsed, stillActive, nll, nllUSED)

Arguments

z

Matrix (m x n) of estimate responsibilities (probabilities that a count comes from a spike distribution at 0).

zUsed

Matrix (m x n) of estimate responsibilities (probabilities that a count comes from a spike distribution at 0) that are actually used (following convergence).

stillActive

A vector of size M booleans saying if a feature is still active or not.

nll

Vector of size M with the current negative log-likelihoods.

nllUSED

Vector of size M with the converged negative log-likelihoods.

Value

A list of updated zUsed and nllUSED.

See Also

fitZig


Function to determine if a feature is still active.

Description

In the Expectation Maximization routine features posterior probabilities routinely converge based on a tolerance threshold. This function checks whether or not the feature's negative log-likelihood (measure of the fit) has changed or not.

Usage

isItStillActive(eps, tol, stillActive, stillActiveNLL, nll)

Arguments

eps

Vector of size M (features) representing the relative difference between the new nll and old nll.

tol

The threshold tolerance for the difference

stillActive

A vector of size M booleans saying if a feature is still active or not.

stillActiveNLL

A vector of size M recording the negative log-likelihoods of the various features, updated for those still active.

nll

Vector of size M with the current negative log-likelihoods.

Value

None.

See Also

fitZig


Access sample depth of coverage from MRexperiment object

Description

Access the libSize vector represents the column (sample specific) sums of features, i.e. the total number of reads for a sample or depth of coverage. It is used by fitZig.

Usage

libSize(object)

Arguments

object

a MRexperiment object

Value

Library sizes

Author(s)

Joseph N. Paulson

Examples

data(lungData)
head(libSize(lungData))

Replace the library sizes in a MRexperiment object

Description

Function to replace the scaling factors, aka the library sizes, of samples in a MRexperiment object.

Usage

## S4 replacement method for signature 'MRexperiment,numeric'
libSize(object) <- value

Arguments

object

a MRexperiment object

value

vector of library sizes

Value

vector library sizes

Author(s)

Joseph N. Paulson

Examples

data(lungData)
head(libSize(lungData)<- rnorm(1))

Load objects organized in the Biom format.

Description

Wrapper to load Biom formatted object.

Usage

loadBiom(file)

Arguments

file

The biom object filepath.

Value

A MRexperiment object.

See Also

loadMeta loadPhenoData newMRexperiment biom2MRexperiment

Examples

#library(biomformat)
rich_dense_file = system.file("extdata", "rich_dense_otu_table.biom", package = "biomformat")
x = loadBiom(rich_dense_file)
x

Load a count dataset associated with a study.

Description

Load a matrix of OTUs in a tab delimited format

Usage

loadMeta(file, sep = "\t")

Arguments

file

Path and filename of the actual data file.

sep

File delimiter.

Value

A list with objects 'counts' and 'taxa'.

See Also

loadPhenoData

Examples

dataDirectory <- system.file("extdata", package="metagenomeSeq")
lung = loadMeta(file.path(dataDirectory,"CHK_NAME.otus.count.csv"))

Load a count dataset associated with a study set up in a Qiime format.

Description

Load a matrix of OTUs in Qiime's format

Usage

loadMetaQ(file)

Arguments

file

Path and filename of the actual data file.

Value

An list with 'counts' containing the count data, 'taxa' containing the otu annotation, and 'otus'.

See Also

loadMeta loadPhenoData

Examples

# see vignette

Load a clinical/phenotypic dataset associated with a study.

Description

Load a matrix of metadata associated with a study.

Usage

loadPhenoData(file, tran = TRUE, sep = "\t")

Arguments

file

Path and filename of the actual clinical file.

tran

Boolean. If the covariates are along the columns and samples along the rows, then tran should equal TRUE.

sep

The separator for the file.

Value

The metadata as a dataframe.

See Also

loadMeta

Examples

dataDirectory <- system.file("extdata", package="metagenomeSeq")
clin = loadPhenoData(file.path(dataDirectory,"CHK_clinical.csv"),tran=TRUE)

OTU abundance matrix of samples from a smoker/non-smoker study

Description

This is a list with a matrix of OTU counts,otu names, taxa annotations for each OTU, and phenotypic data. Samples along the columns and OTUs along the rows.

Format

A list of OTU matrix, taxa, otus, and phenotypes

Value

MRexperiment-class object of 16S lung samples.

References

http://www.ncbi.nlm.nih.gov/pubmed/21680950


Function to make labels simpler

Description

Beginning to transition to better axes for plots

Usage

makeLabels(x = "samples", y = "abundance", norm, log)

Arguments

x

string for the x-axis

y

string for the y-axis

norm

is the data normalized?

log

is the data logged?

Value

vector of x,y labels

Examples

metagenomeSeq::makeLabels(norm=TRUE,log=TRUE)

Merge two MRexperiment objects together

Description

This function will take two MRexperiment objects and merge them together finding common OTUs. If there are OTUs not found in one of the two MRexperiments then a message will announce this and values will be coerced to zero for the second table.

Usage

mergeMRexperiments(x, y)

Arguments

x

MRexperiment-class object 1.

y

MRexperiment-class object 2.

Value

Merged MRexperiment-class object.

Examples

data(mouseData)
newobj = mergeMRexperiments(mouseData,mouseData)
newobj

# let me know if people are interested in an option to merge by keys instead of row names.
data(lungData)
newobj = mergeMRexperiments(mouseData,lungData)
newobj

Merge two tables

Description

Merge two tables

Usage

mergeTable(x, y)

Arguments

x

Table 1.

y

Table 2.

Value

Merged table


Depcrecated functions in the metagenomeSeq package.

Description

These functions may be removed completely in the next release.

Usage

deprecated_metagenomeSeq_function(x, value, ...)

Arguments

x

For assignment operators, the object that will undergo a replacement (object inside parenthesis).

value

For assignment operators, the value to replace with (the right side of the assignment).

...

For functions other than assignment operators, parameters to be passed to the modern version of the function (see table).


OTU abundance matrix of mice samples from a diet longitudinal study

Description

This is a list with a matrix of OTU counts, taxa annotations for each OTU, otu names, and vector of phenotypic data. Samples along the columns and OTUs along the rows.

Format

A list of OTU matrix, taxa, otus, and phenotypes

Value

MRexperiment-class object of 16S mouse samples.

References

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2894525/


Table of top-ranked features from fitZig or fitFeatureModel

Description

Extract a table of the top-ranked features from a linear model fit. This function will be updated soon to provide better flexibility similar to limma's topTable.

Usage

MRcoefs(
  obj,
  by = 2,
  coef = NULL,
  number = 10,
  taxa = obj@taxa,
  uniqueNames = FALSE,
  adjustMethod = "fdr",
  alpha = 0.1,
  group = 0,
  eff = 0,
  numberEff = FALSE,
  counts = 0,
  file = NULL
)

Arguments

obj

Output of fitFeatureModel or fitZig.

by

Column number or column name specifying which coefficient or contrast of the linear model is of interest.

coef

Column number(s) or column name(s) specifying which coefficient or contrast of the linear model to display.

number

The number of bacterial features to pick out.

taxa

Taxa list.

uniqueNames

Number the various taxa.

adjustMethod

Method to adjust p-values by. Default is "FDR". Options include "holm", "hochberg", "hommel", "bonferroni", "BH", "BY", "fdr", "none". See p.adjust for more details. Additionally, options using independent hypothesis weighting (IHW) are available. See MRihw for more details.

alpha

Value for p-value significance threshold when running IHW. The default is set to 0.1

group

One of five choices, 0,1,2,3,4. 0: the sort is ordered by a decreasing absolute value coefficient fit. 1: the sort is ordered by the raw coefficient fit in decreasing order. 2: the sort is ordered by the raw coefficient fit in increasing order. 3: the sort is ordered by the p-value of the coefficient fit in increasing order. 4: no sorting.

eff

Filter features to have at least a "eff" quantile or number of effective samples.

numberEff

Boolean, whether eff should represent quantile (default/FALSE) or number.

counts

Filter features to have at least 'counts' counts.

file

Name of output file, including location, to save the table.

Value

Table of the top-ranked features determined by the linear fit's coefficient.

See Also

fitZig fitFeatureModel MRtable MRfulltable

Examples

data(lungData)
k = grep("Extraction.Control",pData(lungData)$SampleType)
lungTrim = lungData[,-k]
lungTrim=filterData(lungTrim,present=30)
lungTrim=cumNorm(lungTrim,p=0.5)
smokingStatus = pData(lungTrim)$SmokingStatus
mod = model.matrix(~smokingStatus)
fit = fitZig(obj = lungTrim,mod=mod)
head(MRcoefs(fit))
####
fit = fitFeatureModel(obj = lungTrim,mod=mod)
head(MRcoefs(fit))

Accessor for the counts slot of a MRexperiment object

Description

The counts slot holds the raw count data representing (along the rows) the number of reads annotated for a particular feature and (along the columns) the sample.

Usage

MRcounts(obj, norm = FALSE, log = FALSE, sl = 1000)

Arguments

obj

a MRexperiment object.

norm

logical indicating whether or not to return normalized counts.

log

TRUE/FALSE whether or not to log2 transform scale.

sl

The value to scale by (default=1000).

Value

Normalized or raw counts

Author(s)

Joseph N. Paulson, [email protected]

Examples

data(lungData)
head(MRcounts(lungData))

Class "MRexperiment" – a modified eSet object for the data from high-throughput sequencing experiments

Description

This is the main class for metagenomeSeq.

Objects from the Class

Objects should be created with calls to newMRexperiment.

Extends

Class eSet (package 'Biobase'), directly. Class VersionedBiobase (package 'Biobase'), by class "eSet", distance 2. Class Versioned (package 'Biobase'), by class "eSet", distance 3.

Methods

Class-specific methods.

[

Subset operation, taking two arguments and indexing the sample and variable. Returns an MRexperiment object, including relevant metadata. Setting drop=TRUE generates an error. Subsetting the data, the experiment summary slot is repopulated and pData is repopulated after calling factor (removing levels not present).

Note

Note: This is a summary for reference. For an explanation of the actual usage, see the vignette.

MRexperiments are the main class in use by metagenomeSeq. The class extends eSet and provides additional slots which are populated during the analysis pipeline.

MRexperiment dataset are created with calls to newMRexperiment. MRexperiment datasets contain raw count matrices (integers) accessible through MRcounts. Similarly, normalized count matrices can be accessed (following normalization) through MRcounts by calling norm=TRUE. Following an analysis, a matrix of posterior probabilities for counts is accessible through posteriorProbs.

The normalization factors used in analysis can be recovered by normFactors, as can the library sizes of samples (depths of coverage), libSize.

Similarly to other RNASeq bioconductor packages available, the rows of the matrix correspond to a feature (be it OTU, species, gene, etc.) and each column an experimental sample. Pertinent clinical information and potential confounding factors are stored in the phenoData slot (accessed via pData).

To populate the various slots in an MRexperiment several functions are run. 1) cumNormStat calculates the proper percentile to calculate normalization factors. The cumNormStat slot is populated. 2) cumNorm calculates the actual normalization factors using p = cumNormStat.

Other functions will place subsequent matrices (normalized counts (cumNormMat), posterior probabilities (posteriorProbs))

As mentioned above, MRexperiment is derived from the virtual class,eSet and thereby has a phenoData slot which allows for sample annotation. In the phenoData data frame factors are stored. The normalization factors and library size information is stored in a slot called expSummary that is an annotated data frame and is repopulated for subsetted data.

Examples

# See vignette

MRexperiment to biom objects

Description

Wrapper to convert MRexperiment objects to biom objects.

Usage

MRexperiment2biom(
  obj,
  id = NULL,
  norm = FALSE,
  log = FALSE,
  sl = 1000,
  qiimeVersion = TRUE
)

Arguments

obj

The MRexperiment object.

id

Optional id for the biom matrix.

norm

normalize count table

log

log2 transform count table

sl

scaling factor for normalized counts.

qiimeVersion

Format fData according to QIIME specifications (assumes only taxonomy in fData).

Value

A biom object.

See Also

loadMeta loadPhenoData newMRexperiment loadBiom biom2MRexperiment


Table of top microbial marker gene from linear model fit including sequence information

Description

Extract a table of the top-ranked features from a linear model fit. This function will be updated soon to provide better flexibility similar to limma's topTable. This function differs from link{MRcoefs} in that it provides other information about the presence or absence of features to help ensure significant features called are moderately present.

Usage

MRfulltable(
  obj,
  by = 2,
  coef = NULL,
  number = 10,
  taxa = obj@taxa,
  uniqueNames = FALSE,
  adjustMethod = "fdr",
  group = 0,
  eff = 0,
  numberEff = FALSE,
  ncounts = 0,
  file = NULL
)

Arguments

obj

Output of fitFeatureModel or fitZig.

by

Column number or column name specifying which coefficient or contrast of the linear model is of interest.

coef

Column number(s) or column name(s) specifying which coefficient or contrast of the linear model to display.

number

The number of bacterial features to pick out.

taxa

Taxa list.

uniqueNames

Number the various taxa.

adjustMethod

Method to adjust p-values by. Default is "FDR". Options include "holm", "hochberg", "hommel", "bonferroni", "BH", "BY", "fdr", "none". See p.adjust for more details.

group

One of five choices: 0,1,2,3,4. 0: the sort is ordered by a decreasing absolute value coefficient fit. 1: the sort is ordered by the raw coefficient fit in decreasing order. 2: the sort is ordered by the raw coefficient fit in increasing order. 3: the sort is ordered by the p-value of the coefficient fit in increasing order. 4: no sorting.

eff

Filter features to have at least a "eff" quantile or number of effective samples.

numberEff

Boolean, whether eff should represent quantile (default/FALSE) or number.

ncounts

Filter features to those with at least 'counts' counts.

file

Name of output file, including location, to save the table.

Value

Table of the top-ranked features determined by the linear fit's coefficient.

See Also

fitZig fitFeatureModel MRcoefs MRtable fitPA

Examples

data(lungData)
k = grep("Extraction.Control",pData(lungData)$SampleType)
lungTrim = lungData[,-k]
lungTrim=filterData(lungTrim,present=30)
lungTrim=cumNorm(lungTrim,p=0.5)
smokingStatus = pData(lungTrim)$SmokingStatus
mod = model.matrix(~smokingStatus)
fit = fitZig(obj = lungTrim,mod=mod)
head(MRfulltable(fit))
####
fit = fitFeatureModel(obj = lungTrim,mod=mod)
head(MRfulltable(fit))

MRihw runs IHW within a MRcoefs() call

Description

Function used in MRcoefs() when "IHW" is set as the p value adjustment method

Usage

MRihw(obj, ...)

Arguments

obj

Either a fitFeatureModelResults or fitZigResults object

...

other parameters


MRihw runs IHW within a MRcoefs() call

Description

Function used in MRcoefs() when "IHW" is set as the p value adjustment method

Usage

## S4 method for signature 'fitFeatureModelResults'
MRihw(obj, p, adjustMethod, alpha)

Arguments

obj

Either a fitFeatureModelResults or fitZigResults object

p

a vector of pvalues extracted from obj

adjustMethod

Value specifying which adjustment method and which covariate to use for IHW pvalue adjustment. For obj of class fitFeatureModelResults-class, options are "ihw-abundance" (median feature count per row) and "ihw-ubiquity" (number of non-zero features per row). For obj of class fitZigResults-class, options are "ihw-abundance" (weighted mean per feature) and "ihw-ubiquity" (number of non-zero features per row).

alpha

pvalue significance level specified for IHW call. Default is 0.1


MRihw runs IHW within a MRcoefs() call

Description

Function used in MRcoefs() when "IHW" is set as the p value adjustment method

Usage

## S4 method for signature 'fitZigResults'
MRihw(obj, p, adjustMethod, alpha)

Arguments

obj

Either a fitFeatureModelResults or fitZigResults object

p

a vector of pvalues extracted from obj

adjustMethod

Value specifying which adjustment method and which covariate to use for IHW pvalue adjustment. For obj of class fitFeatureModelResults-class, options are "ihw-abundance" (median feature count per row) and "ihw-ubiquity" (number of non-zero features per row). For obj of class fitZigResults-class, options are "ihw-abundance" (weighted mean per feature) and "ihw-ubiquity" (number of non-zero features per row).

alpha

pvalue significance level specified for IHW call. Default is 0.1


Table of top microbial marker gene from linear model fit including sequence information

Description

Extract a table of the top-ranked features from a linear model fit. This function will be updated soon to provide better flexibility similar to limma's topTable. This function differs from link{MRcoefs} in that it provides other information about the presence or absence of features to help ensure significant features called are moderately present.

Usage

MRtable(
  obj,
  by = 2,
  coef = NULL,
  number = 10,
  taxa = obj@taxa,
  uniqueNames = FALSE,
  adjustMethod = "fdr",
  group = 0,
  eff = 0,
  numberEff = FALSE,
  ncounts = 0,
  file = NULL
)

Arguments

obj

Output of fitFeatureModel or fitZig.

by

Column number or column name specifying which coefficient or contrast of the linear model is of interest.

coef

Column number(s) or column name(s) specifying which coefficient or contrast of the linear model to display.

number

The number of bacterial features to pick out.

taxa

Taxa list.

uniqueNames

Number the various taxa.

adjustMethod

Method to adjust p-values by. Default is "FDR". Options include "holm", "hochberg", "hommel", "bonferroni", "BH", "BY", "fdr", "none". See p.adjust for more details.

group

One of five choices, 0,1,2,3,4. 0: the sort is ordered by a decreasing absolute value coefficient fit. 1: the sort is ordered by the raw coefficient fit in decreasing order. 2: the sort is ordered by the raw coefficient fit in increasing order. 3: the sort is ordered by the p-value of the coefficient fit in increasing order. 4: no sorting.

eff

Filter features to have at least a "eff" quantile or number of effective samples.

numberEff

Boolean, whether eff should represent quantile (default/FALSE) or number.

ncounts

Filter features to have at least 'counts' of counts.

file

Name of file, including location, to save the table.

Value

Table of the top-ranked features determined by the linear fit's coefficient.

See Also

fitZig fitFeatureModel MRcoefs MRfulltable

Examples

data(lungData)
k = grep("Extraction.Control",pData(lungData)$SampleType)
lungTrim = lungData[,-k]
lungTrim=filterData(lungTrim,present=30)
lungTrim=cumNorm(lungTrim,p=0.5)
smokingStatus = pData(lungTrim)$SmokingStatus
mod = model.matrix(~smokingStatus)
fit = fitZig(obj = lungTrim,mod=mod)
head(MRtable(fit))
####
fit = fitFeatureModel(obj = lungTrim,mod=mod)
head(MRtable(fit))

Create a MRexperiment object

Description

This function creates a MRexperiment object from a matrix or data frame of count data.

Usage

newMRexperiment(
  counts,
  phenoData = NULL,
  featureData = NULL,
  libSize = NULL,
  normFactors = NULL
)

Arguments

counts

A matrix or data frame of count data. The count data is representative of the number of reads annotated for a feature (be it gene, OTU, species, etc). Rows should correspond to features and columns to samples.

phenoData

An AnnotatedDataFrame with pertinent sample information.

featureData

An AnnotatedDataFrame with pertinent feature information.

libSize

libSize, library size, is the total number of reads for a particular sample.

normFactors

normFactors, the normalization factors used in either the model or as scaling factors of sample counts for each particular sample.

Details

See MRexperiment-class and eSet (from the Biobase package) for the meaning of the various slots.

Value

an object of class MRexperiment

Author(s)

Joseph N Paulson

Examples

cnts = matrix(abs(rnorm(1000)),nc=10)
obj <- newMRexperiment(cnts)

Access the normalization factors in a MRexperiment object

Description

Function to access the scaling factors, aka the normalization factors, of samples in a MRexperiment object.

Usage

normFactors(object)

Arguments

object

a MRexperiment object

Value

Normalization scaling factors

Author(s)

Joseph N. Paulson

Examples

data(lungData)
head(normFactors(lungData))

Replace the normalization factors in a MRexperiment object

Description

Function to replace the scaling factors, aka the normalization factors, of samples in a MRexperiment object.

Usage

## S4 replacement method for signature 'MRexperiment,numeric'
normFactors(object) <- value

Arguments

object

a MRexperiment object

value

vector of normalization scaling factors

Value

Normalization scaling factors

Author(s)

Joseph N. Paulson

Examples

data(lungData)
head(normFactors(lungData)<- rnorm(1))

Basic plot of binned vectors.

Description

This function plots takes two vectors, calculates the contingency table and plots circles sized by the contingency table value. Optional significance vectors of the values significant will shade the circles by proportion of significance.

Usage

plotBubble(
  yvector,
  xvector,
  sigvector = NULL,
  nbreaks = 10,
  ybreak = quantile(yvector, p = seq(0, 1, length.out = nbreaks)),
  xbreak = quantile(xvector, p = seq(0, 1, length.out = nbreaks)),
  scale = 1,
  local = FALSE,
  ...
)

Arguments

yvector

A vector of values represented along y-axis.

xvector

A vector of values represented along x-axis.

sigvector

A vector of the names of significant features (names should match x/yvector).

nbreaks

Number of bins to break yvector and xvector into.

ybreak

The values to break the yvector at.

xbreak

The values to break the xvector at.

scale

Scaling of circle bin sizes.

local

Boolean to shade by signficant bin numbers (TRUE) or overall proportion (FALSE).

...

Additional plot arguments.

Value

A matrix of features along rows, and the group membership along columns.

See Also

plotMRheatmap

Examples

data(mouseData)
mouseData = mouseData[which(rowSums(mouseData)>139),]
sparsity = rowMeans(MRcounts(mouseData)==0)
lor = log(fitPA(mouseData,cl=pData(mouseData)[,3])$oddsRatio)
plotBubble(lor,sparsity,main="lor ~ sparsity")
# Example 2
x = runif(100000)
y = runif(100000)
plotBubble(y,x)

Plot abundances by class

Description

Plot the abundance of values for each class using a spline approach on the estimated full model.

Usage

plotClassTimeSeries(
  res,
  formula,
  xlab = "Time",
  ylab = "Abundance",
  color0 = "black",
  color1 = "red",
  include = c("1", "class", "time:class"),
  ...
)

Arguments

res

Output of fitTimeSeries function

formula

Formula for ssanova. Of the form: abundance ~ ... where ... includes any pData slot value.

xlab

X-label.

ylab

Y-label.

color0

Color of samples from first group.

color1

Color of samples from second group.

include

Parameters to include in prediction.

...

Extra plotting arguments.

Value

Plot for abundances of each class using a spline approach on estimated null model.

See Also

fitTimeSeries

Examples

data(mouseData)
res = fitTimeSeries(obj=mouseData,feature="Actinobacteria",
   class="status",id="mouseID",time="relativeTime",lvl='class',B=10)
plotClassTimeSeries(res,pch=21,bg=res$data$class,ylim=c(0,8))

Basic correlation plot function for normalized or unnormalized counts.

Description

This function plots a heatmap of the "n" features with greatest variance across rows.

Usage

plotCorr(obj, n, norm = TRUE, log = TRUE, fun = cor, ...)

Arguments

obj

A MRexperiment object with count data.

n

The number of features to plot. This chooses the "n" features with greatest variance.

norm

Whether or not to normalize the counts - if MRexperiment object.

log

Whether or not to log2 transform the counts - if MRexperiment object.

fun

Function to calculate pair-wise relationships. Default is pearson correlation

...

Additional plot arguments.

Value

plotted correlation matrix

See Also

cumNormMat

Examples

data(mouseData)
plotCorr(obj=mouseData,n=200,cexRow = 0.4,cexCol = 0.4,trace="none",dendrogram="none",
         col = colorRampPalette(brewer.pal(9, "RdBu"))(50))

Basic plot function of the raw or normalized data.

Description

This function plots the abundance of a particular OTU by class. The function is the typical manhattan plot of the abundances.

Usage

plotFeature(
  obj,
  otuIndex,
  classIndex,
  col = "black",
  sort = TRUE,
  sortby = NULL,
  norm = TRUE,
  log = TRUE,
  sl = 1000,
  ...
)

Arguments

obj

A MRexperiment object with count data.

otuIndex

The row to plot

classIndex

A list of the samples in their respective groups.

col

A vector to color samples by.

sort

Boolean, sort or not.

sortby

Default is sort by library size, alternative vector for sorting

norm

Whether or not to normalize the counts - if MRexperiment object.

log

Whether or not to log2 transform the counts - if MRexperiment object.

sl

Scaling factor - if MRexperiment and norm=TRUE.

...

Additional plot arguments.

Value

counts and classindex

See Also

cumNorm

Examples

data(mouseData)
classIndex=list(Western=which(pData(mouseData)$diet=="Western"))
classIndex$BK=which(pData(mouseData)$diet=="BK")
otuIndex = 8770

par(mfrow=c(2,1))
dates = pData(mouseData)$date
plotFeature(mouseData,norm=FALSE,log=FALSE,otuIndex,classIndex,
col=dates,sortby=dates,ylab="Raw reads")

Basic plot function of the raw or normalized data.

Description

This function plots the abundance of a particular OTU by class. The function uses the estimated posterior probabilities to make technical zeros transparent.

Usage

plotGenus(
  obj,
  otuIndex,
  classIndex,
  norm = TRUE,
  log = TRUE,
  no = 1:length(otuIndex),
  labs = TRUE,
  xlab = NULL,
  ylab = NULL,
  jitter = TRUE,
  jitter.factor = 1,
  pch = 21,
  ...
)

Arguments

obj

An MRexperiment object with count data.

otuIndex

A list of the otus with the same annotation.

classIndex

A list of the samples in their respective groups.

norm

Whether or not to normalize the counts - if MRexperiment object.

log

Whether or not to log2 transform the counts - if MRexperiment object.

no

Which of the otuIndex to plot.

labs

Whether to include group labels or not. (TRUE/FALSE)

xlab

xlabel for the plot.

ylab

ylabel for the plot.

jitter

Boolean to jitter the count data or not.

jitter.factor

Factor value for jitter

pch

Standard pch value for the plot command.

...

Additional plot arguments.

Value

plotted data

See Also

cumNorm

Examples

data(mouseData)
classIndex=list(controls=which(pData(mouseData)$diet=="BK"))
classIndex$cases=which(pData(mouseData)$diet=="Western")
otuIndex = grep("Strep",fData(mouseData)$family)
otuIndex=otuIndex[order(rowSums(MRcounts(mouseData)[otuIndex,]),decreasing=TRUE)]
plotGenus(mouseData,otuIndex,classIndex,no=1:2,xaxt="n",norm=FALSE,ylab="Strep normalized log(cpt)")

Basic heatmap plot function for normalized counts.

Description

This function plots a heatmap of the 'n' features with greatest variance across rows (or other statistic).

Usage

plotMRheatmap(obj, n, norm = TRUE, log = TRUE, fun = sd, ...)

Arguments

obj

A MRexperiment object with count data.

n

The number of features to plot. This chooses the 'n' features of greatest positive statistic.

norm

Whether or not to normalize the counts - if MRexperiment object.

log

Whether or not to log2 transform the counts - if MRexperiment object.

fun

Function to select top 'n' features.

...

Additional plot arguments.

Value

plotted matrix

See Also

cumNormMat

Examples

data(mouseData)
trials = pData(mouseData)$diet
heatmapColColors=brewer.pal(12,"Set3")[as.integer(factor(trials))];
heatmapCols = colorRampPalette(brewer.pal(9, "RdBu"))(50)
#### version using sd
plotMRheatmap(obj=mouseData,n=200,cexRow = 0.4,cexCol = 0.4,trace="none",
             col = heatmapCols,ColSideColors = heatmapColColors)
#### version using MAD
plotMRheatmap(obj=mouseData,n=50,fun=mad,cexRow = 0.4,cexCol = 0.4,trace="none",
             col = heatmapCols,ColSideColors = heatmapColColors)

Plot of either PCA or MDS coordinates for the distances of normalized or unnormalized counts.

Description

This function plots the PCA / MDS coordinates for the "n" features of interest. Potentially uncovering batch effects or feature relationships.

Usage

plotOrd(
  obj,
  tran = TRUE,
  comp = 1:2,
  norm = TRUE,
  log = TRUE,
  usePCA = TRUE,
  useDist = FALSE,
  distfun = stats::dist,
  dist.method = "euclidian",
  n = NULL,
  ...
)

Arguments

obj

A MRexperiment object or count matrix.

tran

Transpose the matrix.

comp

Which components to display

norm

Whether or not to normalize the counts - if MRexperiment object.

log

Whether or not to log2 the counts - if MRexperiment object.

usePCA

TRUE/FALSE whether to use PCA or MDS coordinates (TRUE is PCA).

useDist

TRUE/FALSE whether to calculate distances.

distfun

Distance function, default is stats::dist

dist.method

If useDist==TRUE, what method to calculate distances.

n

Number of features to make use of in calculating your distances.

...

Additional plot arguments.

Value

coordinates

See Also

cumNormMat

Examples

data(mouseData)
cl = pData(mouseData)[,3]
plotOrd(mouseData,tran=TRUE,useDist=TRUE,pch=21,bg=factor(cl),usePCA=FALSE)

Basic plot function of the raw or normalized data.

Description

This function plots the abundance of a particular OTU by class. The function uses the estimated posterior probabilities to make technical zeros transparent.

Usage

plotOTU(
  obj,
  otu,
  classIndex,
  log = TRUE,
  norm = TRUE,
  jitter.factor = 1,
  pch = 21,
  labs = TRUE,
  xlab = NULL,
  ylab = NULL,
  jitter = TRUE,
  ...
)

Arguments

obj

A MRexperiment object with count data.

otu

The row number/OTU to plot.

classIndex

A list of the samples in their respective groups.

log

Whether or not to log2 transform the counts - if MRexperiment object.

norm

Whether or not to normalize the counts - if MRexperiment object.

jitter.factor

Factor value for jitter.

pch

Standard pch value for the plot command.

labs

Whether to include group labels or not. (TRUE/FALSE)

xlab

xlabel for the plot.

ylab

ylabel for the plot.

jitter

Boolean to jitter the count data or not.

...

Additional plot arguments.

Value

Plotted values

See Also

cumNorm

Examples

data(mouseData)
classIndex=list(controls=which(pData(mouseData)$diet=="BK"))
classIndex$cases=which(pData(mouseData)$diet=="Western")
# you can specify whether or not to normalize, and to what level
plotOTU(mouseData,otu=9083,classIndex,norm=FALSE,main="9083 feature abundances")

Plot of rarefaction effect

Description

This function plots the number of observed features vs. the depth of coverage.

Usage

plotRare(obj, cl = NULL, ...)

Arguments

obj

A MRexperiment object with count data or matrix.

cl

Vector of classes for various samples.

...

Additional plot arguments.

Value

Library size and number of detected features

See Also

plotOrd, plotMRheatmap, plotCorr, plotOTU, plotGenus

Examples

data(mouseData)
cl = factor(pData(mouseData)[,3])
res = plotRare(mouseData,cl=cl,pch=21,bg=cl)
tmp=lapply(levels(cl), function(lv) lm(res[,"ident"]~res[,"libSize"]-1, subset=cl==lv))
for(i in 1:length(levels(cl))){
   abline(tmp[[i]], col=i)
}
legend("topleft", c("Diet 1","Diet 2"), text.col=c(1,2),box.col=NA)

Plot difference function for particular bacteria

Description

Plot the difference in abundance for significant features.

Usage

plotTimeSeries(
  res,
  C = 0,
  xlab = "Time",
  ylab = "Difference in abundance",
  main = "SS difference function prediction",
  ...
)

Arguments

res

Output of fitTimeSeries function

C

Value for which difference function has to be larger or smaller than (default 0).

xlab

X-label.

ylab

Y-label.

main

Main label.

...

Extra plotting arguments.

Value

Plot of difference in abundance for significant features.

See Also

fitTimeSeries

Examples

data(mouseData)
res = fitTimeSeries(obj=mouseData,feature="Actinobacteria",
   class="status",id="mouseID",time="relativeTime",lvl='class',B=10)
plotTimeSeries(res)

Access the posterior probabilities that results from analysis

Description

Accessing the posterior probabilities following a run through fitZig

Usage

posteriorProbs(obj)

Arguments

obj

a MRexperiment object.

Value

Matrix of posterior probabilities

Author(s)

Joseph N. Paulson

Examples

# This is a simple demonstration 
data(lungData)
k = grep("Extraction.Control",pData(lungData)$SampleType)
lungTrim = lungData[,-k]
k = which(rowSums(MRcounts(lungTrim)>0)<30)
lungTrim = cumNorm(lungTrim)
lungTrim = lungTrim[-k,]
smokingStatus = pData(lungTrim)$SmokingStatus
mod = model.matrix(~smokingStatus)
# The maxit is not meant to be 1 -- this is for demonstration/speed
settings = zigControl(maxit=1,verbose=FALSE)
fit = fitZig(obj = lungTrim,mod=mod,control=settings)
head(posteriorProbs(lungTrim))

Check if MRexperiment or matrix and return matrix

Description

Function to check if object is a MRexperiment class or matrix

Usage

returnAppropriateObj(obj, norm, log, sl = 1000)

Arguments

obj

a MRexperiment or matrix object

norm

return a normalized MRexperiment matrix

log

return a log transformed MRexperiment matrix

sl

scaling value

Value

Matrix

Examples

data(lungData)
head(returnAppropriateObj(lungData,norm=FALSE,log=FALSE))

smoothing-splines anova fit

Description

Sets up a data-frame with the feature abundance, class information, time points, sample ids and returns the fitted values for the fitted model.

Usage

ssFit(
  formula,
  abundance,
  class,
  time,
  id,
  include = c("class", "time:class"),
  pd,
  ...
)

Arguments

formula

Formula for ssanova. Of the form: abundance ~ ... where ... includes any pData slot value.

abundance

Numeric vector of abundances.

class

Class membership (factor of group membership).

time

Time point vector of relative times (same length as abundance).

id

Sample / patient id.

include

Parameters to include in prediction.

pd

Extra variable.

...

Extra parameters for ssanova function (see ?ssanova).

Value

A list containing:

  • data : Inputed data

  • fit : The interpolated / fitted values for timePoints

  • se : The standard error for CI intervals

  • timePoints : The time points interpolated over

See Also

cumNorm fitTimeSeries ssPermAnalysis ssPerm ssIntervalCandidate

Examples

# Not run

calculate interesting time intervals

Description

Calculates time intervals of interest using SS-Anova fitted confidence intervals.

Usage

ssIntervalCandidate(fit, standardError, timePoints, positive = TRUE, C = 0)

Arguments

fit

SS-Anova fits.

standardError

SS-Anova se estimates.

timePoints

Time points interpolated over.

positive

Positive region or negative region (difference in abundance is positive/negative).

C

Value for which difference function has to be larger or smaller than (default 0).

Value

Matrix of time point intervals of interest

See Also

cumNorm fitTimeSeries ssFit ssPerm ssPermAnalysis

Examples

# Not run

class permutations for smoothing-spline time series analysis

Description

Creates a list of permuted class memberships for the time series permuation tests.

Usage

ssPerm(df, B)

Arguments

df

Data frame containing class membership and sample/patient id label.

B

Number of permutations.

Value

A list of permutted class memberships

See Also

cumNorm fitTimeSeries ssFit ssPermAnalysis ssIntervalCandidate

Examples

# Not run

smoothing-splines anova fits for each permutation

Description

Calculates the fit for each permutation and estimates the area under the null (permutted) model for interesting time intervals of differential abundance.

Usage

ssPermAnalysis(
  data,
  formula,
  permList,
  intTimes,
  timePoints,
  include = c("class", "time:class"),
  ...
)

Arguments

data

Data used in estimation.

formula

Formula for ssanova. Of the form: abundance ~ ... where ... includes any pData slot value.

permList

A list of permutted class memberships

intTimes

Interesting time intervals.

timePoints

Time points to interpolate over.

include

Parameters to include in prediction.

...

Options for ssanova

Value

A matrix of permutted area estimates for time intervals of interest.

See Also

cumNorm fitTimeSeries ssFit ssPerm ssIntervalCandidate

Examples

# Not run

Trapezoidal Integration

Description

Compute the area of a function with values 'y' at the points 'x'. Function comes from the pracma package.

Usage

trapz(x, y)

Arguments

x

x-coordinates of points on the x-axis

y

y-coordinates of function values

Value

Approximated integral of the function from 'min(x)' to 'max(x)'. Or a matrix of the same size as 'y'.

Examples

# Calculate the area under the sine curve from 0 to pi:
 n <- 101
 x <- seq(0, pi, len = n)
 y <- sin(x)
 trapz(x, y)          #=> 1.999835504

# Use a correction term at the boundary: -h^2/12*(f'(b)-f'(a))
 h  <- x[2] - x[1]
 ca <- (y[2]-y[1]) / h
 cb <- (y[n]-y[n-1]) / h
 trapz(x, y) - h^2/12 * (cb - ca)  #=> 1.999999969

With a list of fitTimeSeries results, generate an MRexperiment that can be plotted with metavizr

Description

With a list of fitTimeSeries results, generate an MRexperiment that can be plotted with metavizr

Usage

ts2MRexperiment(
  obj,
  sampleNames = NULL,
  sampleDescription = "timepoints",
  taxonomyLevels = NULL,
  taxonomyHierarchyRoot = "bacteria",
  taxonomyDescription = "taxonomy",
  featuresOfInterest = NULL,
  featureDataOfInterest = NULL
)

Arguments

obj

Output of fitMultipleTimeSeries

sampleNames

Sample names for plot

sampleDescription

Description of samples for plot axis label

taxonomyLevels

Feature names for plot

taxonomyHierarchyRoot

Root of feature hierarchy for MRexperiment

taxonomyDescription

Description of features for plot axis label

featuresOfInterest

The features to select from the fitMultipleTimeSeries output

featureDataOfInterest

featureData for the resulting MRexperiment

Value

MRexperiment that contains fitTimeSeries data, featureData, and phenoData

See Also

fitTimeSeries fitMultipleTimeSeries

Examples

data(mouseData)
res = fitMultipleTimeSeries(obj=mouseData,lvl='phylum',class="status",
          id="mouseID",time="relativeTime",B=1)
obj = ts2MRexperiment(res)
obj

Table of features unique to a group

Description

Creates a table of features, their index, number of positive samples in a group, and the number of reads in a group. Can threshold features by a minimum no. of reads or no. of samples.

Usage

uniqueFeatures(obj, cl, nsamples = 0, nreads = 0)

Arguments

obj

Either a MRexperiment object or matrix.

cl

A vector representing assigning samples to a group.

nsamples

The minimum number of positive samples.

nreads

The minimum number of raw reads.

Value

Table of features unique to a group

Examples

data(mouseData)
head(uniqueFeatures(mouseData[1:100,],cl=pData(mouseData)[,3]))

Computes normalization factors using wrench instead of cumNorm

Description

Calculates normalization factors using method published by M. Sentil Kumar et al. (2018) to compute normalization factors which considers compositional bias introduced by sequencers.

Usage

wrenchNorm(obj, condition)

Arguments

obj

an MRexperiment object

condition

case control label that wrench uses to calculate normalization factors

Value

an MRexperiment object with updated normalization factors. Accessible by normFactors.

See Also

cumNorm fitZig

Examples

data(mouseData)
mouseData <- wrenchNorm(mouseData, condition = mouseData$diet)
head(normFactors(mouseData))

Settings for the fitZig function

Description

Settings for the fitZig function

Usage

zigControl(
  tol = 1e-04,
  maxit = 10,
  verbose = TRUE,
  dfMethod = "modified",
  pvalMethod = "default"
)

Arguments

tol

The tolerance for the difference in negative log likelihood estimates for a feature to remain active.

maxit

The maximum number of iterations for the expectation-maximization algorithm.

verbose

Whether to display iterative step summary statistics or not.

dfMethod

Either 'default' or 'modified' (by responsibilities).

pvalMethod

Either 'default' or 'bootstrap'.

Value

The value for the tolerance, maximum no. of iterations, and the verbose warning.

Note

fitZig makes use of zigControl.

See Also

fitZig cumNorm plotOTU

Examples

control =  zigControl(tol=1e-10,maxit=10,verbose=FALSE)