I am using the Combat module on the Gene Pattern platform to analyse qPCR data and correct for batch variations. I keep getting the following error that I cannot interpret :
Error in matrix(0, length(vec), nlevels(vec) - start + 1) :
invalid 'ncol' value (< 0)
Calls: parseCmdLine ... gp.combat.R -> ComBat -> design.mat -> build.design -> matrix
I would appreciate any help in figuring out what this means and how to avoid the error.