tikz produces empty file in R loop

Question

I am using the tikzDevice library in R to produce tikzpicture plots in latex. It works when plots are produced one by one. However, when I want to produce the plots in a loop, I get empty files. This issue is illustrated in the following minimal example:

library(ggplot2)
library(tikzDevice)

df <- data.frame(
    x = c(1, 2),
    y = c(1, 2)
)

path <- 'some path here'

for (j in 1:25){

    filename <- paste(path, j, sep = '')
    filename <- paste(filename, '.tex', sep = '')

    tikz(file = filename)

    plot <-
        ggplot(data=df, aes(x=x, y=y)) 
    plot
    dev.off()

}

This produces 25 empty plots. However, if I run the code without the for loop (for instance, copying the content in the loop 25 times and changing j accordingly, then it produces the plots. What is the problem here?

Answer 1

plot(plot) or one loses the plot