I am trying to use heatmap.send() in package sendplot with the example data given in 'A tutorial for sendplot R package', Section 4. The code I am using (copied from tutorial) is: data(mtcars) x <- as.matrix(mtcars) xy.labels=list(value=x) x.labels=data.frame(label=colnames(x), description=c("Miles/(US) gallon","Numberof cylinders", "Displacement (cu.in.)", "Gross horsepower", "Rear axle ratio", "Weight (lb/1000)", "1/4 mile time", "V/S", "Transmission (0 = automatic, 1 = manual)", "Number of forward gears", "Number of carburetors") ) rc <- rainbow(nrow(x),start=0,end=.3) cc = rainbow(ncol(x), start=0, end=.3) heatmap.send(x,scale="column",xy.labels=xy.labels,x.labels=x.labels, RowSideColors = rc, ColSideColors = cc, margin=c(5,10), xlab="specification variables", ylab="Car Models", main = "mtcars data", fname.root="exHeat", dir=".", font.size=18,image.size="600x900") Unfortunately I get the error: ERROR: could not map. one of the required tif files is not found Missing either .exHeatDot.tif or .exHeat.tif Error in boundingPt$up.left : $ operator is invalid for atomic vectors sessionInfo() R version 3.0.2 (2013-09-25) Platform: x86_64-pc-linux-gnu (64-bit) locale: [1] C attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] sendplot_4.0.0 rtiff_1.4.4 pixmap_0.4-11 loaded via a namespace (and not attached): [1] KernSmooth_2.23-10 bitops_1.0-6 caTools_1.16 gdata_2.13.2 [5] gplots_2.12.1 grid_3.0.2 gtools_3.3.1 lattice_0.20-27 [9] tools_3.0.2 Thank you.