The function plots the distribution of gene set statistic values under the null hypothesis. It requires the
significance assessment step of the enrichment analysis configuration (parameter significance or gsAnalysis) to be a computer-intensive testing procedure that yields a distribution of gene set statistic p-values under the null hypothesis. Predefined configurations for which this plot works are analysis.gsea, analysis.averageCorrelation and analysis.averageTStatistic.
A histogram is plotted for the analysis in x. If x includes the analyses for several gene sets, one histogram is plotted for each of the gene sets.
The statistic value of the input set is depicted as a vertical line.
The most common graphical parameters can be supplied as vectors (one entry per analyzed gene set) to vary them between the different analyses. These parameters are: main, xlab, ylab.