goat (version 1.1.2)

test_genesets: Perform geneset enrichment testing using any supported method

Description

Perform geneset enrichment testing using any supported method

Usage

test_genesets(
  genesets,
  genelist,
  method,
  padj_method = "BH",
  padj_sources = TRUE,
  padj_cutoff = 0.01,
  padj_min_signifgenes = 0L,
  ...
)

Value

the input genesets, with results stored in columns 'pvalue', 'pvalue_adjust' and 'signif'

Arguments

genesets

tibble with genesets, must contain columns 'source', 'source_version', 'id', 'name', 'genes', 'ngenes', 'ngenes_signif'

genelist

tibble with genes, must contain column 'gene' and 'test'. gene = character column, which are matched against list column 'genes' in genesets tibble. test = boolean column (you can set all to FALSE if not performing Fisher-exact or hypergeometric test downstream)

method

method for overrepresentation analysis. Options: "goat", "hypergeometric", "fisherexact", "fisherexact_ease", "gsea", "idea"

padj_method

first step of multiple testing correction; method for p-value adjustment, passed to stats::p.adjust() via padjust_genesets(), e.g. set "BH" to compute FDR adjusted p-values (default) or "bonferroni" for a more stringent procedure

padj_sources

second step of multiple testing correction; apply Bonferroni adjustment to all p-values according to the number of geneset sources that were tested. Boolean parameter, set TRUE to enable (default) or FALSE to disable

padj_cutoff

cutoff for adjusted p-value, signif column is set to TRUE for all values lesser-equals

padj_min_signifgenes

if a value larger than zero is provided, this will perform additional post-hoc filtering; after p-value adjustment, set the pvalue_adjust to NA and signif to FALSE for all genesets with fewer than padj_min_signifgenes 'input genes that were significant' (ngenes_signif column in genesets table). So this does not affect the accuracy of estimated p-values, in contrast to prefiltering genesets prior to p-value computation or adjusting p-values

...

further parameters are passed to the respective stats method

Details

After application of the enrichment testing algorithm (e.g. GOAT, ORA or GSEA), multiple testing correction is applied to obtain adjusted p-values using padjust_genesets. That function will first apply the specified pvalue adjustment procedure in the padj_method parameter within each 'source' in the genesets table. Second, it applies Bonferroni adjustment to all p-values according to the number of different geneset sources that were tested (or set padj_sources = FALSE to disable).

For example, if the input is a genesets table that contains GO_CC, GO_BP and GO_MF genesets, first multiple testing correction is applied within each source (e.g. using FDR if so desired) and afterwards a Bonferroni correction is applied based on 3 repeated analyses.

Note that this is more rigorous than typical GO tools; hypothetically, one could split all GO_CC pathways into 1000 different databases/'sources' and then run enrichment testing. Consequently, the multiple testing burden is reduced if one doesn't adjust p-values for the number of 'sources' as we do here.

Examples

# \donttest{
#' # note; this example downloads data when first run, and typically takes ~60seconds

## Basic example for a complete GOAT workflow
# Downloads test data to your computer and stores it at current working directory
# Refer to the GitHub documentation for elaborate documentation and a worked example

# store the downloaded files in the following directory. Here, the temporary file
# directory is used. Alternatively, consider storing this data in a more permanent location.
# e.g. output_dir="~/data/go" on unix systems or output_dir="C:/data/go" on Windows
output_dir = tempdir()

# download an example gene list
datasets = download_goat_manuscript_data(output_dir)
genelist = datasets$`Wingo 2020:mass-spec:PMID32424284`

# download GO genesets
genesets_asis = download_genesets_goatrepo(output_dir)

# filter genesets for sufficient overlap with the genelist, then apply GOAT
genesets_filtered = filter_genesets(genesets_asis, genelist)
result = test_genesets(genesets_filtered, genelist, method = "goat",
  score_type = "effectsize", padj_method = "bonferroni", padj_cutoff = 0.05)

# print first 10 rows of the result table
print(result |> select(source, name, ngenes, pvalue_adjust) |> utils::head(n=10))
# }