I am following the tutorial on sPLSDA:SRBCT with my dataset. I tried to do a preliminar PLS-DA tuned to 10 components in order to see the error rate and use the optimal ncomp for the sPLS-DA. As my number of samples is low (i.e., 47), I prefer using loo-cv. But when seeing the output of choice.ncomp, the table has only NAs:
coda_plsda <- plsda(codapls.dat, codapls.fac, ncomp = 10, mode = "regression") coda_plsda_tune <- perf(coda_plsda, validation = "loo") coda_plsda_tune$choice.ncomp max.dist centroids.dist mahalanobis.dist overall NA NA NA BER NA NA NA
Is this normal? If so, should I use the
plot(coda_plsda_tune) or is there another way to select my optimal ncomp?
Thanks a lot!