the p-value as determined using the hypergeometric distribution.
Arguments
term_genes
vector of genes in the selected term gene set
chosen_genes
vector containing the set of input genes
background_genes
vector of background genes (i.e. universal set of
genes in the experiment)
Details
To determine whether the chosen_genes are enriched
(compared to a background pool of genes) in the term_genes, the
hypergeometric distribution is assumed and the appropriate p value
(the value under the right tail) is calculated and returned.