ComputePairWiseDE: Find markers (differentially expressed genes) between two...

Description Usage Arguments Value

View source: R/computePairDE.R

Description

Find markers (differentially expressed genes) between two group of cells.

Usage

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ComputePairWiseDE(
  object,
  cells.1 = NULL,
  cells.2 = NULL,
  features = NULL,
  logfc.threshold = 1.5,
  test.use = "wilcox",
  min.pct = 0.25,
  min.diff.pct = -Inf,
  verbose = TRUE,
  only.pos = FALSE,
  max.cells.per.ident = Inf,
  random.seed = 1,
  min.cells.group = 3,
  pseudocount.use = 1,
  MeanExprsThrs = 0,
  p.adjust.methods = "BH"
)

Arguments

object

dataMatrix of genes (rows) x cells (columns) expression matrix (log normalized value)

cells.1

Vector of cell names belonging to group 1

cells.2

Vector of cell names belonging to group 2

features

Genes to test. Default is NULL which mean to use all genes

logfc.threshold

Limit testing to genes which show, on average, at least X-fold difference (log-scale) between the two groups of cells. Default is log(1.5)

test.use

Denotes which test to use. Available options are:

  • "wilcox" : Identifies differentially expressed genes between two groups of cells using a Wilcoxon Rank Sum test (default)

  • "bimod" : Likelihood-ratio test for single cell gene expression, (McDavid et al., Bioinformatics, 2013)

  • "roc" : Identifies 'markers' of gene expression using ROC analysis. For each gene, evaluates (using AUC) a classifier built on that gene alone, to classify between two groups of cells. An AUC value of 1 means that expression values for this gene alone can perfectly classify the two groupings (i.e. Each of the cells in cells.1 exhibit a higher level than each of the cells in cells.2). An AUC value of 0 also means there is perfect classification, but in the other direction. A value of 0.5 implies that the gene has no predictive power to classify the two groups. Returns a 'predictive power' (abs(AUC-0.5) * 2) ranked matrix of putative differentially expressed genes.

  • "t" : Identify differentially expressed genes between two groups of cells using the Student's t-test.

min.pct

only test genes that are detected in a minimum fraction of min.pct cells in either of the two populations. Meant to speed up the function by not testing genes that are very infrequently expressed. Default is 0.25

min.diff.pct

only test genes that show a minimum difference in the fraction of detection between the two groups. Set to -Inf by default

verbose

Print a progress bar once expression testing begins

only.pos

Only return positive markers (FALSE by default)

max.cells.per.ident

Down sample each identity class to a max number. Default is no downsampling. Not activated by default (set to Inf)

random.seed

Random seed for downsampling. default is 1

min.cells.group

Minimum number of cells in one of the groups

pseudocount.use

Pseudocount to add to averaged expression values when calculating logFC. 1 by default.

MeanExprsThrs

a minimum expression threshold of average cluster expression for a gene to be considered a DE gene. the mean expression value is in the linear scale!

p.adjust.methods

correction method for calculating qvalue. default is BH (or FDR)

Value

returnObj returnObj = list( 'list CompGeneList: List of genes for which the DE statistical test was performed for each pairwise cluster comparison list qValueList: list of q-values from the DE statistical test for genes where test was performed for each pairwise cluster comparison list log2FCList: list of log2-fold-changes from the DE statistical test for genes where test was performed for each pairwise cluster comparison= character vector deGeneUnion: union of top ndeg DE genes from up- and down- regulated set for all pairwise comparison numeric matrix deCountMatrix: matrix with number of DE genes for each pairwise cluster comparison list deGeneRegulationList: list of up and down regulated DE genes for each pairwise cluster comparison ordered by log2-fold-change list log2FCDEList: list of log2-fold-change for up and down regulated DE genes for each pairwise cluster comparison - corresponds to same order as in deGeneRegulationList list qValueDEList: list of q-values for up and down regulated DE genes for each pairwise cluster comparison - corresponds to same order as in deGeneRegulationList list upregulatedDEGeneList: list of cluster-specific upregulated DE genes list downregulatedDEGeneList: list of cluster-specific downregulated DE genes )


linquynus/RCAv2-beta documentation built on Aug. 9, 2020, 12:34 a.m.