Reputation: 971
While trying to create a Heatmap in R as mentioned in http://davetang.org/muse/2010/12/06/making-a-heatmap-with-r/
data <- read.table("test.txt",sep="\t",header=TRUE,row.names=1)
data_matrix <- data.matrix(data)
install.packages("RColorBrewer")
library("RColorBrewer")
heatmap(data_matrix,Colv=NA,col=brewer.pal(9,"Blues"))
How do I get the scale of colours beside the heatmap that shows range of values corresponding to shades of colours used, (small value corresponding to light shade and high value to a dark shade) similar to the first heatmap in Creating a continuous heat map in R
Upvotes: 0
Views: 2176
Reputation: 6532
I am simply copying/adapting the following example code from the ggplot2 docs site:
> library(ggplot2)
> library(reshape2) # for melt
> M=melt(volcano)
> head(M)
Var1 Var2 value
1 1 1 100
2 2 1 101
3 3 1 102
4 4 1 103
5 5 1 104
6 6 1 105
> ggplot(M, aes(x=Var1, y=Var2, fill=value)) + geom_tile()
geom_tile
is the important bit here. You can choose your own colours by adding something like e.g.
+ scale_fill_gradient(low="green", high="red")
Upvotes: 1