Coloring a specific cell in pheatmap graph

Question

I'm trying to color arbitrary cells cells in a diagram created with the R package pheatmap.

Short example:

library (pheatmap)

dat <- as.data.frame (scale (mtcars))

pheatmap (dat,
          color = colorRampPalette (c ("white", "red")) (5),
          cluster_rows = FALSE,
          cluster_cols = FALSE,
)

results in this:

What I would like is to color specific cells in arbitrary colors, so I get something like this:

Any ideas how I could achieve that?

Answer 1

You can set to NA the cells that you need to color differently. Then, using the na_col option of pheatmap, you can set the color for these cells.

library (pheatmap)
dat <- as.data.frame(scale(mtcars))

# Set to NA the cells 
dat[, 10] <- NA
dat[10, 6] <- NA
dat[16, 4:6] <- NA

pheatmap(dat,
          color = colorRampPalette (c ("white", "red")) (5),
          cluster_rows = FALSE,
          cluster_cols = FALSE,
          na_col = "blue"
)