Calculate Membership Functions with DFP package in R for ALL dataset

Question

[h72ghorashi]

Hi, I'm using calculateMembershipFunctions from DFP package in R to find membership functions for ALL microarray dataset from package ALL.Here is this line of my code:

mfs<-calculateMembershipFunctions(ALL, skipFactor = 3)

I get the below error.

Error in names(rmav) <- sampleNames(rmadataset) : 
attempt to set an attribute on NULL

But I'm not using the default dataset (that is rmadataset), Can anyone please tell me what's wrong with this line of code? Thanks in advance