I want to use subplot function to plot 6 ggplots in a 2 rows x 4 columns grid.

Here is a reproducible example:

figlist <- list()
for (i in 1:6) figlist[[i]] <- ggplot(data.frame(a = 1:3,b = 4:6), aes(a,b)) + geom_point()
subplot(figlist, nrows = 2, widths = rep(0.25,4))

This generates "Error: The length of the widths argument must be equal to the number of columns"

Looking into the code of subplots.R, the subplot function accepts arguments nrows, widths and heights, which appear to be passed through to get_domains.

The problem is that get_domains calculates ncols ignoring length(widths) and then generates an error when these don't match.

I would have expected get_domains to calculate ncols only if widths was not supplied.

I hope this helps.