In this recipe, we will make a heat map that shows the variation in values of one variable (z
) along the x and y axes as a grid of colors and display a scale alongside.
We will only use the base graphics functions for this recipe. So, just open up the R prompt and type in the following code. We will use the sales.csv
example dataset for this recipe. So, let's first load it:
sales<-read.csv("sales.csv")
We will use the RColorBrewer
package for some good color palettes. So, let's make sure that it's installed and loaded:
install.packages("RColorBrewer") library(RColorBrewer)
The sales
dataset has monthly sales data for four cities. Let's make a heat map with the months along the x axis and the cities on the y axis:
rownames(sales)<-sales[,1] sales<-sales[,-1] data_matrix<-data.matrix(sales) pal=brewer.pal(7,"YlOrRd") breaks<-seq(3000,12000,1500) #Create layout with 1 row and 2 columns (for the heatmap...