Package 'miRcomp'

Title: Tools to assess and compare miRNA expression estimatation methods
Description: Based on a large miRNA dilution study, this package provides tools to read in the raw amplification data and use these data to assess the performance of methods that estimate expression from the amplification curves.
Authors: Matthew N. McCall <[email protected]>, Lauren Kemperman <[email protected]>
Maintainer: Matthew N. McCall <[email protected]>
License: GPL-3 | file LICENSE
Version: 1.35.0
Built: 2024-09-28 04:12:12 UTC
Source: https://github.com/bioc/miRcomp

Help Index


Assess the accuracy of the expression estimates

Description

This function assesses the signal detect slope (a measure of accuracy) for each feature.

Usage

accuracy(object1, qcThreshold1, object2=NULL, qcThreshold2=NULL, 
commonFeatures=TRUE, bins=3, label1=NULL, label2=NULL)

Arguments

object1

a list containing two elements: ct (the expression estimates) and qc (quality scores)

qcThreshold1

a numeric threshold corresponding to object1$qc below which values are considered low quality.

object2

an optional second list of the same format as object1, used to compare two methods.

qcThreshold2

a numeric threshold corresponding to object2$qc below which values are considered low quality.

commonFeatures

if TRUE and object2 is non-NULL, only high quality non-NA features in common between both objects are used.

bins

the number of bins to divide the data into.

label1

optional label corresponding to object 1 to be used in plotting.

label2

optional label corresponding to object 2 to be used in plotting.

Value

A plot of signal detect slopes stratified by difference in pure sample expression is produced, and a summary (median and MAD) of the signal detect slopes in each bin is returned.

Author(s)

Matthew N. McCall

Examples

data(lifetech)
  accuracy(object1=lifetech,qcThreshold1=1.25)
  data(qpcRdefault)
  accuracy(object1=lifetech,qcThreshold1=1.25,
           object2=qpcRdefault,qcThreshold2=0.99)

Determine the Number of Completely Observed Features

Description

This function determines the number of features that are good quality and non-NA across all samples using a given quality threshold.

Usage

completeFeatures(object1, qcThreshold1, object2=NULL, qcThreshold2=NULL,
label1=NULL, label2=NULL)

Arguments

object1

a list containing two elements: ct (the expression estiamtes) and qc (quality scores)

qcThreshold1

a numeric threshold corresponding to object1$qc below which values are considered low quality.

object2

an optional second list of the same format as object1, used to compare two methods.

qcThreshold2

a numeric threshold corresponding to object2$qc below which values are considered low quality.

label1

optional label corresponding to object 1 to be used in plotting.

label2

optional label corresponding to object 2 to be used in plotting.

Value

The function generates a table of the number of complete, partial, and absent features.

Author(s)

Matthew N. McCall

Examples

data(lifetech)
  completeFeatures(object1=lifetech,qcThreshold1=1.25)
  data(qpcRdefault)
  completeFeatures(object1=lifetech,qcThreshold1=1.25,
           object2=qpcRdefault,qcThreshold2=0.99)

Compare expression estimates between two methods

Description

This function allows one to easily compare the expression estimates generated by two different algorithms. Feature / sample combinations that differ above a given threshold can be easily highlighted.

Usage

expressionComp(object1, qcThreshold1, 
                           object2, qcThreshold2, 
                           label1=NULL, label2=NULL,
                           diffThreshold=2,
                           plotType=c("scatterplot","MAplot"))

Arguments

object1

a list containing two elements: ct (the expression estimates) and qc (quality scores)

qcThreshold1

a numeric threshold corresponding to object1$qc below which values are considered low quality.

object2

a list containing two elements: ct (the expression estimates) and qc (quality scores)

qcThreshold2

a numeric threshold corresponding to object2$qc below which values are considered low quality.

label1

an optional label for plotting on the x-axis

label2

an optional label for plotting on the y-axis

diffThreshold

feature / sample combinations for which the expression estimates differ by more than this value are returned by the function and highlighted in the plot.

plotType

scatterplot or MA-plot

Value

This function plots the expresison estimates produced by two different methods. Feature / sample combinations for which the expression estimates differ by more than diffThreshold are returned by the function and highlighted in the plot.

Author(s)

Matthew N. McCall

Examples

data(lifetech)
  data(qpcRdefault)
  tmp <- expressionComp(object1=lifetech, qcThreshold1=1.25, 
  object2=qpcRdefault,qcThreshold2=0.99,plotType="scatter")

The processed data generated using the LifeTech software.

Description

These data are also used to demonstrate the functionality of the miRcomp package.

Usage

data(lifetech)

Format

A list with two elements.

ct a miRNA x sample matrix of expression estimates
qc a miRNA x sample matrix of quality scores (here AmpScores)

Examples

data(lifetech)

Assess the limit of detection of a given method

Description

This function assesses the limit of detection in one of two ways: (1) the distribution of expression estimates stratified by the proportion of poor quality values within replicates, (2) the average vs expected expression for the two most diluted sample types.

Usage

limitOfDetection(object, qcThreshold, plotType=c("boxplot","scatterplot","MAplot"))

Arguments

object

a list containing two elements: ct (the expression estiamtes) and qc (quality scores)

qcThreshold

a numeric threshold corresponding to object1$qc below which values are considered low quality.

plotType

the desired output type – boxplot is option (1); scatterplot is option (2), an MA-plot is option (3).

Value

This function assesses the limit of detection in several ways. If plotType is boxplot, then boxplots of expression estimates stratified by the proportion of poor quality values within replicates is displayed. The function also outputs a list with the values plotted in each box of the boxplot. If plotType is scatterplot, then the average within replicate expression vs expected expression (based on pure sample expression) is displayed for the 0.1/0.1 dilution and 0.01/0.01 dilution. If plotType is MAplot, then the difference in expression (average within replicate expression - expected expression) is displayed for the 0.1/0.1 dilution and 0.01/0.01 dilution. For both plotTypes, scatterplot and MAplot, the function outputs a matrix containing estimates of the limit of detection for four different tolerances. Specifically, the two columns correspond to the two dilutions (0.1/0.1 and 0.01/0.01) and rows correspond to the median difference between the observed and expected values. The values in the matrix are the expected expression values such that the median absolute difference of all larger expected expression values is approximately equal to the given tolerance.

Author(s)

Matthew N. McCall

Examples

data(lifetech)
  tmp <- limitOfDetection(object=lifetech,qcThreshold=1.25)
  data(qpcRdefault)
  limitOfDetection(object=qpcRdefault,qcThreshold=0.99,plotType="scatter")

Launch a Shiny app to use the miRcomp package interactively

Description

This function launches the miRcomp Shiny app locally.

Usage

miRcompShinyApp()

Author(s)

Matthew N. McCall and Lauren Kemperman

Examples

## miRcompShinyApp()

Assess the precision of the expression estimates

Description

This function assesses the within-replicate precision for each feature.

Usage

precision(object1, qcThreshold1, object2=NULL, qcThreshold2=NULL,
          commonFeatures=TRUE, statistic=c("sd","cv"),
          scale=c("none","log","log10"), bins=3,
          label1=NULL, label2=NULL)

Arguments

object1

a list containing two elements: ct (the expression estiamtes) and qc (quality scores)

qcThreshold1

a numeric threshold corresponding to object1$qc below which values are considered low quality.

object2

an optional second list of the same format as object1, used to compare two methods.

qcThreshold2

a numeric threshold corresponding to object2$qc below which values are considered low quality.

commonFeatures

if TRUE and object2 is non-NULL, only high quality non-NA features in common between both objects are used.

statistic

whether to compute the standard deviation (sd) or coefficient of variation (cv).

scale

optional scaling of the values. This can help with visualizing the distributions.

bins

the number of bins to divide the data into.

label1

optional label corresponding to object 1 to be used in plotting.

label2

optional label corresponding to object 2 to be used in plotting.

Value

A boxplot of either the standard deviation or coefficient of variation stratified by expression is produced. The values plotted in each box of the boxplot are returned.

Author(s)

Matthew N. McCall

Examples

data(lifetech)
  tmp1 <- precision(object1=lifetech,qcThreshold1=1.25)
  data(qpcRdefault)
  tmp2 <- precision(object1=lifetech,qcThreshold1=1.25,
           object2=qpcRdefault,qcThreshold2=0.99)

The processed data generated using the 4 parameter sigmoidal method from the qpcR software.

Description

These data are also used to demonstrate the functionality of the miRcomp package.

Usage

data(qpcRb4)

Format

A list with two elements.

ct a miRNA x sample matrix of expression estimates
qc a miRNA x sample matrix of quality scores (here R-squared values)

Examples

data(qpcRb4)

The processed data generated using the 5 parameter sigmodial method from the qpcR software.

Description

These data are also used to demonstrate the functionality of the miRcomp package.

Usage

data(qpcRb5)

Format

A list with two elements.

ct a miRNA x sample matrix of expression estimates
qc a miRNA x sample matrix of quality scores (here R-squared values)

Examples

data(qpcRb5)

The processed data generated using the default method (4 parameter log-logistic) implemented in the qpcR software package.

Description

These data are also used to demonstrate the functionality of the miRcomp package.

Usage

data(qpcRdefault)

Format

A list with two elements.

ct a miRNA x sample matrix of expression estimates
qc a miRNA x sample matrix of quality scores (here R-squared values)

Examples

data(qpcRdefault)

The processed data generated using the 5 parameter log-logistic method from the qpcR software.

Description

These data are also used to demonstrate the functionality of the miRcomp package.

Usage

data(qpcRl5)

Format

A list with two elements.

ct a miRNA x sample matrix of expression estimates
qc a miRNA x sample matrix of quality scores (here R-squared values)

Examples

data(qpcRl5)

The processed data generated using the linear-exponential method implemented in the qpcR software package.

Description

These data are also used to demonstrate the functionality of the miRcomp package.

Usage

data(qpcRlinexp)

Format

A list with two elements.

ct a miRNA x sample matrix of expression estimates
qc a miRNA x sample matrix of quality scores (here R-squared values)

Examples

data(qpcRlinexp)

Quality Assessment for MicroRNA Expression Estimates

Description

This function produces several figures to examine quality scores.

Usage

qualityAssessment(object1, object2=NULL, cloglog1=FALSE, cloglog2=FALSE, 
                  na.rm=FALSE, plotType=c("scatterplot","boxplot"), 
                  label1=NULL, label2=NULL)

Arguments

object1

a list containing two elements: ct (the expression estiamtes) and qc (quality scores)

object2

an optional second list of the same format as object1, used to compare two methods.

cloglog1

if TRUE, the -log(-log(object1$qc)) is plotted. This is useful to visualize certain quality scores such as R-squared.

cloglog2

if TRUE, the -log(-log(object2$qc)) is plotted. This is useful to visualize certain quality scores such as R-squared.

na.rm

if TRUE, quality scores corresponding to NA expression estimates are removed from analysis. This is only used if plotType=="boxplot".

plotType

type of plot to return. Options are a scatterplot or a boxplot.

label1

optional label corresponding to object 1 to be used in plotting.

label2

optional label corresponding to object 2 to be used in plotting.

Value

The function generates a plot of the desired type.

Author(s)

Matthew N. McCall

Examples

data(lifetech)
  qualityAssessment(lifetech, plotType="boxplot")

  data(qpcRdefault)
  qualityAssessment(object1=lifetech,object2=qpcRdefault,cloglog2=TRUE)

Assess monotone signal across titration

Description

This function determines

Usage

titrationResponse(object1, qcThreshold1, object2=NULL, qcThreshold2=NULL, 
                  commonFeatures=TRUE, label1=NULL, label2=NULL)

Arguments

object1

a list containing two elements: ct (the expression estiamtes) and qc (quality scores)

qcThreshold1

a numeric threshold corresponding to object1$qc below which values are considered low quality.

object2

an optional second list of the same format as object1, used to compare two methods.

qcThreshold2

a numeric threshold corresponding to object2$qc below which values are considered low quality.

commonFeatures

if TRUE and object2 is non-NULL, only high quality non-NA features in common between both objects are used.

label1

optional label corresponding to object 1 to be used in plotting.

label2

optional label corresponding to object 2 to be used in plotting.

Value

A table listing the number of features showing a monotone titration response and a figure showing the proportion of features showing a monotone titration response vs the difference in pure sample expression.

Author(s)

Matthew N. McCall

Examples

data(lifetech)
  titrationResponse(object1=lifetech,qcThreshold1=1.25)
  data(qpcRdefault)
  titrationResponse(object1=lifetech,qcThreshold1=1.25,
           object2=qpcRdefault,qcThreshold2=0.99)