sumcol<-colSums(mat)
eff_relatif<-round(t(apply(mat,1,function(x) {(x/t(as.matrix(sumcol))*1000)})),2)
colnames(eff_relatif) <- colnames(mat)
sumcol<-colSums(mat)
eff_relatif<-round(t(apply(mat,1,function(x) {(x/t(as.matrix(sumcol))*1000)})),2)
colnames(eff_relatif) <- colnames(mat)