groupComparisonTMT: Finding differentially abundant proteins across conditions in...

Description Usage Arguments Value Examples

View source: R/groupComparsionTMT.R

Description

Tests for significant changes in protein abundance across conditions based on a family of linear mixed-effects models in TMT experiment. Experimental design of case-control study (patients are not repeatedly measured) is automatically determined based on proper statistical model.

Usage

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groupComparisonTMT(
  data,
  contrast.matrix = "pairwise",
  moderated = FALSE,
  adj.method = "BH",
  remove_norm_channel = TRUE,
  remove_empty_channel = TRUE
)

Arguments

data

Name of the output of proteinSummarization function. It should have columns named Protein, Mixture, TechRepMixture, Run, Channel, Condition, BioReplicate, Abundance.

contrast.matrix

Comparison between conditions of interests. 1) default is 'pairwise', which compare all possible pairs between two conditions. 2) Otherwise, users can specify the comparisons of interest. Based on the levels of conditions, specify 1 or -1 to the conditions of interests and 0 otherwise. The levels of conditions are sorted alphabetically.

moderated

TRUE will moderate t statistic; FALSE (default) uses ordinary t statistic.

adj.method

adjusted method for multiple comparison. "BH" is default.

remove_norm_channel

TRUE(default) removes 'Norm' channels from protein level data.

remove_empty_channel

TRUE(default) removes 'Empty' channels from protein level data.

Value

data.frame with result of inference

Examples

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data(input.pd)
# use protein.summarization() to get protein abundance data
quant.pd.msstats <- proteinSummarization(input.pd,
                                       method="msstats",
                                       global_norm=TRUE,
                                       reference_norm=TRUE)

test.pairwise <- groupComparisonTMT(quant.pd.msstats, moderated = TRUE)

# Only compare condition 0.125 and 1
levels(quant.pd.msstats$Condition)

# Compare condition 1 and 0.125
comparison<-matrix(c(-1,0,0,1),nrow=1)

# Set the names of each row
row.names(comparison)<-"1-0.125"

# Set the column names
colnames(comparison)<- c("0.125", "0.5", "0.667", "1")
test.contrast <- groupComparisonTMT(data = quant.pd.msstats,
contrast.matrix = comparison,
moderated = TRUE)

huang704/MSstatsTMT documentation built on Jan. 1, 2021, 3:21 a.m.