# High resolution graphics with R

For most purposes PDF or other vector graphic formats such as windows metafile and SVG work just fine. However, if I plot lots of points, say 100k, then those files can get quite large and bitmap formats like PNG can be the better option. I just have to be mindful of the resolution.

As an example I create the following plot:

x <- rnorm(100000)


Saving the plot as a PDF creates a 5.2 MB big file on my computer, while the PNG output is only 62 KB instead. Of course, the PNG doesn’t look as crisp as the PDF file.

png("100kPoints72dpi.png", units = "px", width=400, height=400)
dev.off()

Hence, I increase the resolution to 150 dots per pixel.

png("100kHighRes150dpi.png", units="px", width=400, height=400, res=150)
dev.off()

This looks a bit odd. The file size is only 29 KB but the annotations look too big. Well, the file has only 400 x 400 pixels and the size of a pixel is fixed. Thus, I have to provide more pixels, or in other words increase the plot size. Doubling the width and height as I double the resolution makes sense.

png("100kHighRes150dpi2.png", units="px", width=800, height=800, res=150)
dev.off()

Next I increase the resolution further to 300 dpi and the graphic size to 1600 x 1600 pixels. The file is still very crisp. Of course the file size increased. Now it is 654 KB in size, yet sill only about 1/8 of the PDF and I can embed it in LaTeX as well.

png("100kHighRes300dpi.png", units="px", width=1600, height=1600, res=300)
dev.off()

### Citation

Markus Gesmann (Oct 29, 2013) High resolution graphics with R. Retrieved from https://magesblog.com/post/2013-10-29-high-resolution-graphics-with-r/

BibTeX citation:

@misc{ 2013-high-resolution-graphics-with-r,
author = { Markus Gesmann },
title = { High resolution graphics with R },
url = { https://magesblog.com/post/2013-10-29-high-resolution-graphics-with-r/ },
year = { 2013 }
updated = { Oct 29, 2013 }
}