Dear Bj??rn-Helge, Sorry, I wrote the wrong number of observation. It should be 1184. I saw on the book that variance is defined by sd^2. If variation is a different concept from variance and defined by sd^2*(n-1) ? Since I formerly took variance and variation as the same. Thank you, Shengzhe Shengzhe Wu writes:
I have a data set with 15 variables (first one is the response) and 1200 observations. Now I use pls package to do the plsr as below.
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Because the trainSet has been scaled before training, I think Xtotvar should be equal to 14, but unexpectedly Xtotvar = 16562,
Because the Xtotvar is the "total X variation", measured by sum(X^2) (where X has been centered). With 14 variables, scaled to sd == 1, and 1200 observations, you should get Xtotvar == 14*(1200-1) == 16786. (Maybe you have 1184 observations: 14*1183 == 16562.) -- Bj?rn-Helge Mevik