# Simplest possible heatmap with ggplot2

[This article was first published on

Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

**is.R()**, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

Featuring the lovely “spectral” palette from Colorbrewer. This really just serves as a reminder of how to do four things I frequently want to do:

- Make a heatmap of some kind of matrix, often a square correlation matrix
- Reorder a factor variable, as displayed along the axis of a plot
- Define my own color palette with colorRampPalette()
- Use RColorBrewer, specifically the diverging “spectral” scheme

To

**leave a comment**for the author, please follow the link and comment on their blog:**is.R()**.R-bloggers.com offers

**daily e-mail updates**about R news and tutorials about learning R and many other topics. Click here if you're looking to post or find an R/data-science job.

Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.