Histogram of p-values
A good diagnostic plot is the histogram of p-values. A large density of low p-values indicates many differentially expressed genes; whereas, a uniformly distributed histogram indicates there are few. Create a p-value histogram for the leukemia study.
Latihan ini adalah bagian dari kursus
Differential Expression Analysis with limma in R
Petunjuk latihan
The fitted model object of the leukemia study from Chapter 2, fit2, has been loaded in your workspace. The limma package is already loaded.
Use
topTableto obtain the summary statistics for every gene.To obtain results for every gene, set the argument
numberto be the number of rows offit2.To disable sorting the results by significance level, set the argument
sort.byto"none".Use
histto create a histogram of p-values.
Latihan interaktif praktis
Cobalah latihan ini dengan menyelesaikan kode contoh berikut.
# Obtain the summary statistics for every gene
stats <- ___(fit2, number = ___, sort.by = ___)
# Plot a histogram of the p-values
___(stats[, ___])