Package 'HEM'

Title: Heterogeneous error model for identification of differentially expressed genes under multiple conditions
Description: This package fits heterogeneous error models for analysis of microarray data
Authors: HyungJun Cho <[email protected]> and Jae K. Lee <[email protected]>
Maintainer: HyungJun Cho <[email protected]>
License: GPL (>= 2)
Version: 1.79.0
Built: 2024-10-30 07:25:04 UTC
Source: https://github.com/bioc/HEM

Help Index


AM transformation for LPE

Description

Computes AM for LPE

Author(s)

HyungJun Cho and Jae K. Lee


AM transformation for LPE

Description

Computes AM for LPE

Author(s)

HyungJun Cho and Jae K. Lee


Baseline ASE estimation for oligonucleotide arrays

Description

Estimates baseline error for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline error estimation for oligonucleotide arrays

Description

Estimates baseline error for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline error estimation for oligonucleotide arrays

Description

Estimates baseline error for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline PSE estimation for oligonucleotide arrays

Description

Estimates baseline error for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline error bootstrap estimation for oligonucleotide arrays

Description

Estimates baseline error using bootstrap samples for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline error bootstrap estimation for oligonucleotide arrays

Description

Estimates baseline error using bootstrap samples for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline error bootstrap estimation for oligonucleotide arrays

Description

Estimates baseline error using bootstrap samples for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Prediction using smoothing spine

Description

Makes predictions using smoothing spine

Author(s)

HyungJun Cho and Jae K. Lee


Heterogeneous Error Model for Identification of Differential Expressed Genes Under Multiple Conditions

Description

Fits an error model with heterogeneous experimental and biological variances.

Usage

hem(dat, probe.ID=NULL, n.layer, design, burn.ins=1000, n.samples=3000,
    method.var.e="gam", method.var.b="gam", method.var.t="gam",           
    var.e=NULL, var.b=NULL, var.t=NULL, var.g=1, var.c=1, var.r=1,
    alpha.e=3, beta.e=.1, alpha.b=3, beta.b=.1, alpha.t=3, beta.t=.2,
    n.digits=10, print.message.on.screen=TRUE)

Arguments

dat

data

probe.ID

a vector of probe set IDs

n.layer

number of layers; 1=one-layer EM, 2=two-layer EM

design

design matrix

burn.ins

number of burn-ins for MCMC

n.samples

number of samples for MCMC

method.var.e

prior specification method for experimental variance; "gam"=Gamma(alpha,beta), "peb"=parametric EB prior specification, "neb"=nonparametric EB prior specification

method.var.b

prior specification method for biological variance; "gam"=Gamma(alpha,beta), "peb"=parametric EB prior specification

method.var.t

prior specification method for total variance; "gam"=Gamma(alpha,beta), "peb"=parametric EB prior specification, "neb"=nonparametric EB prior specification

var.e

prior estimate matrix for experimental variance

var.b

prior estimate matrix for biological variance

var.t

prior estimate matrix for total variance

var.g

N(0, var.g); prior parameter for gene effect

var.c

N(0, var.c); prior parameter for condition effect

var.r

N(0, var.r); prior parameter for interaction effect of gene and condition

alpha.e, beta.e

Gamma(alpha.e,alpha.e); prior parameters for inverse of experimental variance

alpha.b, beta.b

Gamma(alpha.b,alpha.b); prior parameters for inverse of biological variance

alpha.t, beta.t

Gamma(alpha.b,alpha.b); prior parameters for inverse of total variance

n.digits

number of digits

print.message.on.screen

if TRUE, process status is shown on screen.

Value

n.gene

numer of genes

n.chip

number of chips

n.cond

number of conditions

design

design matrix

burn.ins

number of burn-ins for MCMC

n.samples

number of samples for MCMC

priors

prior parameters

m.mu

estimated mean expression intensity for each gene under each condition

m.x

estimated unobserved expression intensity for each combination of genes, conditions, and individuals (n.layer=2)

m.var.b

estimated biological variances (n.layer=2)

m.var.e

estimated experiemental variances (n.layer=2)

m.var.t

estimated total variances (n.layer=1)

H

H-scores

Author(s)

HyungJun Cho and Jae K. Lee

References

Cho, H. and Lee, J.K. (2004) Bayesian Hierarchical Error Model for Analysis of Gene Expression Data, Bioinformatics, 20: 2016-2025.

See Also

hem.eb.prior, hem.fdr

Examples

#Example 1: Two-layer HEM

data(pbrain)

##construct a design matrix
cond <- c(1,1,1,1,1,1,2,2,2,2,2,2) #condition
ind  <- c(1,1,2,2,3,3,1,1,2,2,3,3) #biological replicate
rep  <- c(1,2,1,2,1,2,1,2,1,2,1,2) #experimental replicate
design <- data.frame(cond,ind,rep)

##normalization
pbrain.nor <- hem.preproc(pbrain[,2:13])

##fit HEM with two layers of error
##using the small numbers of burn-ins and MCMC samples for a testing purpose;
##but increase the numbers for a practical purpose 
#pbrain.hem <- hem(pbrain.nor, n.layer=2, design=design, 
#                  burn.ins=10, n.samples=30)

##print H-scores
#pbrain.hem$H 


#Example 2: One-layer HEM

data(mubcp)

##construct a design matrix
cond <- c(rep(1,6),rep(2,5),rep(3,5),rep(4,5),rep(5,5))
ind  <- c(1:6,rep((1:5),4))
design <- data.frame(cond,ind)

##construct a design matrix
mubcp.nor <- hem.preproc(mubcp)

#fit HEM with one layers of error
#using the small numbers of burn-ins and MCMC samples for a testing purpose;
#but increase the numbers for a practical purpose 
#mubcp.hem <- hem(mubcp.nor, n.layer=1,design=design, burn.ins=10, n.samples=30)

##print H-scores
#mubcp.hem$H


###NOTE: Use 'hem.fdr' for FDR evaluation
###NOTE: Use 'hem.eb.prior' for Empirical Bayes (EB) prior sepecification
###NOTE: Use EB-HEM ('hem' after 'hem.eb.prior') for small data sets

Empirical Bayes (EB) Prior Specification

Description

Estimates experimental and biological variances by LPE and resampling

Usage

hem.eb.prior(dat,  n.layer, design, 
             method.var.e="neb", method.var.b="peb", method.var.t="neb", 
             rep=TRUE, baseline.var="LPE", p.remove=0, max.chip=4,
             q=0.01, B=25, n.digits=10, print.message.on.screen=TRUE)

Arguments

dat

data

n.layer

number of layers

design

design matrix

method.var.e

prior specification method for experimental variance; "peb"=parametric EB prior specification, "neb"=nonparametric EB prior specification

method.var.b

prior specification method for biological variance; "peb"=parametric EB prior specification

method.var.t

prior specification method for total variance; "peb"=parametric EB prior specification, "neb"=nonparametric EB prior specification

rep

no replication if FALSE

baseline.var

baseline variance estimation method: LPE for replicated data and BLPE, PSE, or ASE for unreplicated data

p.remove

percent of removed rank-variance genes for BLPE

max.chip

maximum number of chips to estimate errors

q

quantile for paritioning genes based on expression levels

B

number of iterations for resampling

n.digits

number of digits

print.message.on.screen

if TRUE, process status is shown on screen.

Value

var.b

prior estimate matrix for biological variances (n.layer=2)

var.e

prior estimate matrix for experiemtnal variances (n.layer=2)

var.t

prior estimate matrix for total variances (n.layer=1)

Author(s)

HyungJun Cho and Jae K. Lee

See Also

hem, hem.fdr

Examples

#Example 1: Two-layer HEM with EB prior specification

data(pbrain)

##construct a design matrix
cond <- c(1,1,1,1,1,1,2,2,2,2,2,2)
ind  <- c(1,1,2,2,3,3,1,1,2,2,3,3)
rep  <- c(1,2,1,2,1,2,1,2,1,2,1,2)
design <- data.frame(cond,ind,rep)

##normalization
pbrain.nor <- hem.preproc(pbrain[,2:13])

##take a subset for a testing purpose;
##use all genes for a practical purpose
pbrain.nor <- pbrain.nor[1:1000,]

##estimate hyperparameters of variances by LPE
#pbrain.eb  <- hem.eb.prior(pbrain.nor, n.layer=2,  design=design,
#                           method.var.e="neb", method.var.b="peb")     

#fit HEM with two layers of error
#using the small numbers of burn-ins and MCMC samples for a testing purpose;
#but increase the numbers for a practical purpose 
#pbrain.hem <- hem(pbrain.nor, n.layer=2,  design=design,burn.ins=10, n.samples=30, 
#              method.var.e="neb", method.var.b="peb", 
#              var.e=pbrain.eb$var.e, var.b=pbrain.eb$var.b)


#Example 2: One-layer HEM with EB prior specification

data(mubcp)

##construct a design matrix
cond <- c(rep(1,6),rep(2,5),rep(3,5),rep(4,5),rep(5,5))
ind  <- c(1:6,rep((1:5),4))
design <- data.frame(cond,ind)

##normalization
mubcp.nor <- hem.preproc(mubcp)

##take a subset for a testing purpose;
##use all genes for a practical purpose
mubcp.nor <- mubcp.nor[1:1000,] 

##estimate hyperparameters of variances by LPE
#mubcp.eb  <- hem.eb.prior(mubcp.nor, n.layer=1, design=design,
#             method.var.t="neb")                                

#fit HEM with two layers of error
#using the small numbers of burn-ins and MCMC samples for a testing purpose;
#but increase the numbers for a practical purpose 
#mubcp.hem <- hem(mubcp.nor, n.layer=1, design=design,  burn.ins=10, n.samples=30, 
#             method.var.t="neb", var.t=mubcp.eb$var.t)

FDR Evaluation

Description

Computes resampling-based False Discovery Rate (FDR)

Usage

hem.fdr(dat,  n.layer, design, rep=TRUE, hem.out, eb.out=NULL, n.iter=5, q.trim=0.9,
        target.fdr=c(0.001, 0.005, 0.01, 0.05, 0.1, 0.15, 0.20, 0.30, 0.40, 0.50),
        n.digits=10, print.message.on.screen=TRUE)

Arguments

dat

data

n.layer

number of layers: 1=one-layer EM; 2=two-layer EM

design

design matrix

rep

no replication if FALSE

hem.out

output from hem function

eb.out

output from hem.eb.prior function

n.iter

number of iterations

q.trim

quantile used for estimtaing the proportion of true negatives (pi0)

target.fdr

Target FDRs

n.digits

number of digits

print.message.on.screen

if TRUE, process status is shown on screen.

Value

fdr

H-values and corresponding FDRs

pi0

estimated proportion of true negatives

H.null

H-scores from null data

targets

given target FDRs, corrsponding critical values and numbers of significant genes are provided

Author(s)

HyungJun Cho and Jae K. Lee

See Also

hem.eb.prior hem

Examples

data(pbrain)

##construct a design matrix
cond <- c(1,1,1,1,1,1,2,2,2,2,2,2)
ind  <- c(1,1,2,2,3,3,1,1,2,2,3,3)
rep  <- c(1,2,1,2,1,2,1,2,1,2,1,2)
design <- data.frame(cond,ind,rep)

##normalization
pbrain.nor <- hem.preproc(pbrain[,2:13])

##take a subset for a testing purpose;
##use all genes for a practical purpose
pbrain.nor <- pbrain.nor[1:1000,]

##estimate hyperparameters of variances by LPE
#pbrain.eb  <- hem.eb.prior(pbrain.nor, n.layer=2,  design=design,
#                           method.var.e="neb", method.var.b="peb")     

##fit HEM with two layers of error
##using the small numbers of burn-ins and MCMC samples for a testing purpose;
##but increase the numbers for a practical purpose 
#pbrain.hem <- hem(pbrain.nor, n.layer=2,  design=design,burn.ins=10, n.samples=30, 
#              method.var.e="neb", method.var.b="peb", 
#              var.e=pbrain.eb$var.e, var.b=pbrain.eb$var.b)

##Estimate FDR based on resampling 
#pbrain.fdr <- hem.fdr(pbrain.nor, n.layer=2,  design=design, 
#                  hem.out=pbrain.hem, eb.out=pbrain.eb)

Generation of null data

Description

Generates null data by resampling

Author(s)

HyungJun Cho and Jae K. Lee


Generation of null data

Description

Generates null data by resampling

Author(s)

HyungJun Cho and Jae K. Lee


Generation of null data

Description

Generates null data by resampling

Author(s)

HyungJun Cho and Jae K. Lee


Preprocessing

Description

Performs IQR normalization, thesholding, and log2-transformation

Usage

hem.preproc(x, data.type = "MAS5")

Arguments

x

data

data.type

data type: MAS5 or MAS4

Author(s)

HyungJun Cho and Jae K. Lee

See Also

hem, hem.eb.prior, hem.fdr

Examples

data(pbrain)
pbrain.nor <- hem.preproc(pbrain[,2:13])

Gene expression data for mouse B cell development

Description

This data set consists of gene expression of the five consecutive stages (pre-B1, large pre-B2, small pre-B2, immature B, and mature B cells) of mouse B cell development. The data were obtained with high-density oligonucleotide arrays, Affymetrix Mu11k GeneChips, from flow-cytometrically purified cells.

Usage

data(mubcp)

Format

A matrix containing 13,207 probe sets and 26 chips; first 6 chips for pre-B1 cell and next 20 chips for other stages (5 chips for each)

Source

Hoffmann, R., Seidl, T., Neeb, M., Rolink, A. and Melchers, F. (2002). Changes in gene expression profiles in developing B cells of murine bone marrow, Genome Research 12:98-111.


Baseline error nonparametric estimation for oligonucleotide arrays

Description

Estimates baseline error for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline error nonparametric estimation for oligonucleotide arrays

Description

Estimates baseline error for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline error nonparametric estimation for oligonucleotide arrays

Description

Estimates baseline error for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline error parametric estimation for oligonucleotide arrays

Description

Estimates baseline error for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline error parametric estimation for oligonucleotide arrays

Description

Estimates baseline error for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Baseline error parametric estimation for oligonucleotide arrays

Description

Estimates baseline error for oligonucleotide arrays

Author(s)

HyungJun Cho and Jae K. Lee


Gene expression data for primate brains

Description

This data set consists of gene expression of primate brains (Affymetrix U95A GeneChip). The frozen brains of three humans (H1, H2, H3) and three chimpanzees (C1, C2, C3) were used to take the postmortem tissue samples, and two independent tissue samples for each individual were taken.

Usage

data(pbrain)

Format

A matrix containing 12,600 probe sets and 12 chips (H1,H1,H2,H2,H3,H3,C1,C1,C2,C2,C3,C3); the first column is probe set ID

Source

Enard, W., Khaitovich, P., Klose, J., Zollner, S., Heissig, F., Giavalisco, P., Nieselt-Struwe, K., Muchmore, E., Varki, A., Ravid, R., Doxiadis, G.M., Bontrop, R.R., and Paabo, S. (2002) Intra- and interspecific variation in primate gene expression patterns, Science 296:340-343


Permutation

Description

Permute

Author(s)

HyungJun Cho and Jae K. Lee


Quantile normalization

Description

Performs quantile normalization

Author(s)

HyungJun Cho and Jae K. Lee


Normalization

Description

Normalization

Author(s)

HyungJun Cho and Jae K. Lee


Normalization

Description

Normalization

Author(s)

HyungJun Cho and Jae K. Lee


Quantile normalization

Description

Performs quantile normalization

Author(s)

HyungJun Cho and Jae K. Lee


Remove significant genes

Description

Remove significant genes

Author(s)

HyungJun Cho and Jae K. Lee