Make a Heatmap from CSV/tab delimited file: R - Project Scripts:

I tried this and it is working well:
http://flowingdata.com/2010/01/21/how-to-make-a-heatmap-a-quick-and-easy-solution/

Heatmap:

1. In R-commander, load the Matrix (from CSV, tab delimeted etc) for
heatmap in a name, say "Dataset"

2. Now change the data into matrix
> Dataset <- data.matrix(Dataset)
> Dataset_Matrix <- data.matrix(Dataset)
> Dataset_Heatmap <- heatmap(Dataset_Matrix,Rowv=NA, Colv=NA,col = cm.colors(256), scale="column", margins=c(5,10))

Now you should see a heatmap window

3. Change color
> Dataset_Heatmap <- heatmap(Dataset_Matrix,Rowv=NA, Colv=NA,col = heat.colors(256), scale="column", margins=c(5,10))

Another:
http://www2.warwick.ac.uk/fac/sci/moac/students/peter_cock/python/heatmap/