I perform PLS with pls package in R using plsr
function.
Why am I unable to get the same predicted Y value as when I use the predict
function as when I dot product the regression coefficients with the test data. I have read from other answers that I should be able to do this, especially if the method is set to simpls
.
EDIT:
I did some further testing and it seems like there is a bias/intercept constant that I have not added in. However, from elsewhere I read that with mean centering, the intercept should be 0 and I believe plsr
has already mean centered all my data by default. I am wondering why is there still an intercept and also how can I find this intercept constant from the plsr
model?
EDIT again:
I have found the coef(,intercept=TRUE)
function! However, my question still remains, why is there an intercept when my data has been mean centered (Both X and Y)?
Many thanks for your help!! Let me know if I can clarify anything at all!