tmod (version 0.19)

tmodPCA: PCA plot annotated with tmod

Description

Generate a PCA plot on which each dimension is annotated by a tag cloud based on tmod enrichment test.

Usage

tmodPCA(pca, loadings = NULL, genes, tmodfunc = "tmodCERNOtest",
  plotfunc = pca2d, mode = "simple", components = c(1, 2),
  plot.params = NULL, filter = TRUE, simplify = TRUE, legend = FALSE,
  ...)

Arguments

pca

Object returned by prcomp or a matrix of PCA coordinates. In the latter case, a loading matrix must be provided separately.

loadings

A matrix with loadings

genes

A character vector with gene identifiers

tmodfunc

Name of the tmod enrichment test function to use. Either

plotfunc

Function for plotting the PCA plot. See Details

mode

Type of the plot to generate; see Details. tmodCERNOtest or tmodUtest (tmodHGtest is not suitable)

components

integer vector of length two: components which components to show on the plot. Must be smaller than the number of columns in pca.

plot.params

A list of parameters to be passed to the plotting function. See Details

filter

Whether "uninteresting" modules (with no annotation) should be removed from the tag cloud

simplify

Whether the names of the modules should be simplified

legend

whether a legend should be shown

...

Any further parameters passed to the tmod test function

Value

• A list containing the calculated enrichments as well as the return value from the plotting function

Details

There are three types of plots that can be generated (parameter "mode"): simple, leftbottom and cross. In the "simple" mode, two enrichments are run, on on each component, sorted by absolute loadings of the PCA components. Both "leftbottom" and "cross" run two enrichment analyses on each component, one on the loadings sorted from lowest to largest, and one on the loadings sorted from largetst to lowest. Thus, two tag clouds are displayed per component. In the "leftbottom" mode, the tag clouds are displayed to the left and below the PCA plot. In the "cross" mode, the tag clouds are displayed on each of the four sides of the plot.

By default, the plotting function is pca2d from the pca3d package. Any additional parametrs for pca2d can be passed on using the plot.params parameter. You can define your own function instead of pca2d, however, mind that in any case, there will be two parameters passed to it on the first two positions: pca and components, named "pca" and "components" respectively.

Examples

data(Egambia)
E <- as.matrix(Egambia[,-c(1:3)])
pca <- prcomp(t(E), scale.=TRUE)
group <- rep(c("CTRL", "TB"), each=15)
tmodPCA(pca,
  genes=Egambia$GENE_SYMBOL,
  components=4:3,
  plot.params=list(group=group))