plot_anno_scores {GOfuncR} | R Documentation

## Plot distribution of scores of genes annotated to GO-categories

### Description

Uses the result of a GO-enrichment analysis performed with `go_enrich` and a vector of GO-IDs and plots for each of these GO-IDs the scores of the annotated genes. This refers to the scores that were provided as user-input in the `go_enrich` analysis.
`plot_anno_scores` works with all four tests implemented in `go_enrich` (hypergeometric, Wilcoxon rank-sum, binomial and 2x2 contingency table test), with test-specific output (see details).

### Usage

    plot_anno_scores(res, go_ids, annotations = NULL)

### Arguments

`res` | an object returned from `go_enrich` (list() of 4 elements).
`go_ids` | character() vector of GO-IDs, e.g. c('GO:0005737','GO:0071495'). This specifies the GO-categories that are plotted.
`annotations` | optional data.frame() for custom annotations, with two character() columns: (1) gene-symbols and (2) GO-categories. This is needed if `go_enrich` was run with custom `annotations` to generate `res`, too.

### Details

The plot depends on the statistical test that was specified in the `go_enrich` call.

For the hypergeometric test pie charts show the amounts of candidate and background genes that are annotated to the GO-categories and the root nodes (candidate genes in the colour of the corresponding root node). The top panel shows the odds-ratio and 95%-CI from fisher's exact test (two-sided) comparing the GO-categories with their root nodes. Note that `go_enrich` reports the the hypergeometric tests for over- and under-representation of candidate genes which correspond to the one-sided fisher's exact tests.

For the Wilcoxon rank-sum test violin plots show the distribution of the scores of genes that are annotated to each GO-category and the root nodes. Horizontal lines in the left panel indicate the median of the scores that are annotated to the root nodes. The Wilcoxon rank-sum test reported in the `go_enrich` result compares the scores annotated to a GO-category with the scores annotated to the corresponding root node.

For the binomial test pie charts show the amounts of A and B counts associated with each GO-category and root node, (A in the colour of the corresponding root node). The top-panel shows point estimates and the 95%-CI of p(A) in the nodes, as well as horizontal lines that correspond to p(A) in the root nodes. The p-value in the returned object is based on the null hypothesis that p(A) in a node equals p(A) in the corresponding root node. Note that `go_enrich` reports that value for one-sided binomial tests.

For the 2x2 contingency table test pie charts show the proportions of A and B, as well as C and D counts associated with a GO-category. Root nodes are not shown, because this test is independent of the root category. The top panel shows the odds ratio and 95%-CI from Fisher's exact test (two-sided) comparing A/B and C/D inside one node. Note that in `go_enrich`, if all four values are >=10, a chi-square test is performed instead of fisher's exact test.

### Value

For the hypergeometric, binomial and 2x2 contingency table test, a data.frame() with the statistics that are used in the plots.
For the Wilcoxon rank-sum test no statistical results are plotted, just the distribution of annotated scores. The returned element in this case is a list() with three data frames: annotations of genes to the GO-categories, annotations of genes to the root nodes and a table which contains for every GO-ID the corresponding root node.

### Author(s)

Steffi Grote

### See Also

`go_enrich`
`get_anno_genes`
`get_names`
`vioplot`

### Examples

    #### see the package's vignette for more examples

    #### Note that argument 'n_randsets' is reduced
    #### to lower computational time in the example.

    ## Assign two random counts to some genes to create example input
    set.seed(123)
    high_A_genes = c('G6PD', 'GCK', 'GYS1', 'HK2', 'PYGL', 'SLC2A8',
        'UGP2', 'ZWINT', 'ENGASE')
    low_A_genes = c('CACNG2', 'AGTR1', 'ANO1', 'BTBD3', 'MTUS1', 'CALB1',
        'GYG1', 'PAX2')
    A_counts = c(sample(15:25, length(high_A_genes)),
        sample(5:15, length(low_A_genes)))
    B_counts = c(sample(5:15, length(high_A_genes)),
        sample(15:25, length(low_A_genes)))
    genes = data.frame(gene=c(high_A_genes, low_A_genes), A_counts, B_counts)

    ## perform enrichment analysis to find GO-categories with high fraction of A
    go_binom = go_enrich(genes, test='binomial', n_randsets=20)

    ## plot sums of A and B counts associated with the top GO-categories
    top_gos = head(go_binom[[1]]$node_id)
    stats = plot_anno_scores(go_binom, go_ids=top_gos)

    ## look at the results of binomial test used for plotting
    ## (this is two-sided, go_enrich reports one-sided tests)
    head(stats)

[Package GOfuncR version 1.6.1 Index]