How to loop over correlation matrices to place many plots into a single PDF?

[eyavuz21]

Hello all,

I have the formula below:

pdf('rplotings.pdf')
for (i in 1:length(n_people)){
object3 <- Datarray[, ,i]
object2 <- data.frame(object3)
ggcorrplot(object2) + ggtitle(paste("N=",n_people[i]))
}
dev.off()

What I have tried to do here is place all 20 plots into a single PDF file: the function seems to be running without error but when I try to open the file, it says there is an error?

[pieterjanvc]

Hi,

The reason this is happening is that a loop will only print output if you explicitly tell it to.

# No output printed to console
for(i in 1:10){
  i
}
# Output printed
for(i in 1:10){
  print(i)
}

So to make sure the PDF captures the ggplot, you need to wrap it in the plot() function

library(ggplot2)

pdf(file="test.pdf")
for(i in 1:10){
  plot(ggplot(data.frame(x = 1:10, y = runif(10)), aes(x = x, y = y)) + 
    geom_line())
}
dev.off()

That should fix it... unless there's something wrong with the plots itself of course, but you can check that by running the code inside the loop manually.

Hope this helps,
PJ

[eyavuz21]

Thank you so much! This is so helpful!