Plot p-value function with multiple comparisons

multiple_comparisons.R

library(ggplot2)
library(tidyr)
library(dplyr)

X = matrix(0,10,10)
set.seed(1234)
X[,1:5] = rnorm(50, 0)
X[,6:10] = rnorm(50, 2)

colwise_ttest <- function(X, mu, method=NULL){
  pv = apply(X, 2, function(x)t.test(x, mu = mu, conf.int=FALSE)$p.value)
  p.adjust(pv, method = method)  
}

z = seq(-4, 4, length.out=201)
res_pv = sapply(z, function(mu0){colwise_ttest(X, mu0)})
df_pv = pivot_longer(data.frame(t(res_pv), mu=z), cols = 1:10,
                     names_prefix = "X") %>% 
  mutate(name=factor(as.integer(name)))

p = ggplot(df_pv, aes(x=mu,y=value,group=name))+
  geom_line()+
  facet_grid(row = vars(name))+
  theme_bw(18)

ggsave("pv_m.png", plot = p, width = 8, height = 12)