Hello All if my question is very basic please bear with me because heat map i am leaning. I have sample control vs test with 4000 gene . I took the fpkm value of control and test both in excel sheet along with that i also added the gene name in first column. So my first column is gene name 2nd column is fpkm from control 3column is fpkm from test(this file is one which has no significant or FC filter i means it contain all the genes.) i am trying to generate heatmap using R as of now i tried this command:
a <- read.csv("/home/Desktop/heatmap.csv",sep=",",header=true)
b <- as.matrix(a[,2:3])
heatmap(b,Rowv=TRUE,col=heat.colors(256),cexCol =1.0,margins=c(10,20),offsetRow =5,scale="row",dendrogram="column")
the above command has generated heatmap but the yaxis that is what i assume are gene name the not visible i means just one dark colour line thats it. how to go about i am not sure please help.
Can you post the output of
head /home/Desktop/heatmap.csv # on command line
or
head(a) # in R
If you plot 4000 genes you will not be able to read the gene names from the resulting plot labels, the font size will be too small and the labels will overlap, you will only be able to read the names if you plot only the top few genes.
There is another heatmap command in R, heatmap.2 from the gplots package.