Hi, > The code I have used is > >> summary(prefdata) >> prefdata[prefdata>5]=NA >> summary(prefdata) >> prefdata2=as.matrix(prefdata[3:22]) >> stats=paf(prefdata2) > [1] "One of your variables is a constant. Constants are disallowed as > part of could you provide some data / sample data you used for prefdata and code that is fully reproducible? Regards!