#myGrid <- grid.arrange(.decay = c(0.01,0.05,0.1),
                   .size=c(1,2,3,4,5,6))
     fit.pca2 <- train(pca.X,pca.Y,
              tuneGrid = myGrid,
              method = 'nnet',
              maxit = 1000,
              linout = TRUE,
              trace = FALSE

        )

Error: Please make sure `y` is a factor or numeric value.