Concatenate the rownames in heat map

Question

[najlaksouri]

i need help please

i m trying to create a heat map of deferentially expressed genes i have something like this:

gene Id        Function

cuff.121        NAC100

cuff.122        peroxidase 44

cuff.123        defensin 1

I want to put the 2 columns (gene Id and function) as the rowname, i tried these commands however the final look was not good enough (so compact) and i wanted to have 2 separated blocks for the rowname

r <-read.csv("response to stimulus.csv",header = T,sep = ";",dec = ".")

R1<-r[,1]

R2<-r[,2]

rnames<-paste (S1, S2, sep = "  ")

mat_data <- data.matrix(r[,4:ncol(r)])

rownames(mat_data) <-rnames

my_dist <- daisy(mat_data, metric="euclidean", stand=FALSE) 

nwk_tree <- as.phylo(hclust(my_dist, method="complete"), hang =-1)

[WouterDeCoster]

How does it look like and what do you want? Do you have examples?