Is there an R function to log CPU usage?

Question

I want to run a code chunk and see how much of my CPU is being used. The equivalent of using task manager (activity monitor in mac), is there any R-way to achieve that?

Answer 1

Perhaps you could make a system call, e.g.

cpu_log <- c()
for (i in seq(1, 1000, 1)) {
  print(i)
  cpu_log[[i]] <- system("ps -A -o %cpu | awk '{ cpu += $1} END {print cpu}' ", intern = TRUE)
}

plot(y = cpu_log, x = 1:1000)

Answer 2

I don't know if this is the best way, but you can use proc.time(), which is part of base r.

ptm <- proc.time()

for (i in 1:1000) {rnorm(100000)}  #insert your code here

CPU_usage<-proc.time() - ptm      #compute the difference

CPU_usage

   user  system elapsed 
  6.407   0.385   6.896 

There is more written about user, sys, and elapsed time here.

Answer 3

You can use system.time:

system.time(for(i in 1:100) mad(runif(1000)))
#       User      System verstrichen 
#      0.035       0.000       0.045 

or using profvis:

library(profvis)
profvis({
  dat <- data.frame(
    x = rnorm(5e4),
    y = rnorm(5e4)
  )
  
  plot(x ~ y, data = dat)
  m <- lm(x ~ y, data = dat)
  abline(m, col = "red")
})