ggplot2 make missing value in geom_tile not blank

Question

In the geom_tile() layer in the ggplot2 data visualization package for R, when a cell contains no data it is not drawn. E.g. http://docs.ggplot2.org/current/geo

Answer 1

For posterity, here is the right solution compatible with ggplot2 version 1.9.3

+ theme(panel.background=element_rect(fill="blue", colour="blue")

• In joran's answer, the plot.background is the whole plot including the title and legend etc. The panel.background is the area where the data appears.

• In the latest version of ggplot2, opts has been replaced with theme and theme_rect has been replaced with element_rect.

• In specifying element_rect, color is the boundary of the rectangle while fill is the interior of the rectangle.

I had originally used,

+ geom_rect(aes(xmin=-Inf, xmax=Inf, ymin=-Inf, ymax=Inf), fill="blue")

but when adding geom_raster rather than geom_tile over the the background and generate pdf output, pdf viewers had a very hard time rendering the plot, using substantially more cpu cycles and memory.