ggplot中缺少具有连续比例和远程桌面的颜色条

Question

I am having the problem identified here , namely, on Windows (7) using remote desktop, plots with continuous color scales show up missing the scale. The solution at that link (increase color depth of remote desktop server) is infeasible for me as it's a shared server maintained by a corporate technology team and they aren't willing to change it. I had hoped that saving the plot as a png without displaying it would solve the problem, but doing something like

p <- ggplot(...) ggsave(file='test.png', plot = p)

still fails. Even though the plot is never displayed, it still has missing legend scale. The only workaround I've found is to save it as pdf, display the pdf (where the color bar is displayed) then use the Windows "snipping tool". Obviously this is not an attractive solution for reproducibility. That is,

p <- ggplot(...) ggsave(file='test.pdf', plot = p)

then displaying the file with, say, acrobat reader, then taking a screenshot, works. So the ggplot object p has the required data, but ggsave of a png file loses it when the display depth is 16 bit, even when the figure is saved without displaying. (I need a png or jpg to insert in another doc.)

Any suggestions appreciated.

Answer 1

user12728748's suggestion solved the save-to-file problem.

An alternative, which is a partial solution to the original problem (being unable to see the color scale) is to modify the legend with something like:

guides(fill = guide_legend(override.aes = list(size = 5)))

This replaces the continuous scale legend by an approximate discrete legend, but that is adequate for getting a rough idea of corresponding values.