reference on contr.helmert and typo on its help page.
On Sun, Nov 8, 2009 at 10:11 AM, Duncan Murdoch <murdoch at stats.uwo.ca> wrote:
On 08/11/2009 11:03 AM, Peng Yu wrote:
I'm wondering which textbook discussed the various contrast matrices mentioned in the help page of 'contr.helmert'. Could somebody let me know?
Doesn't the reference on that page discuss them?
It does explain what the functions are. But I need a more basic and complete reference. For example, I want to understand what 'Helmert parametrization' (on page 33 of 'Statistical Models in S') is.
BTW, in R version 2.9.1, there is a typo on the help page of
'contr.helmert' ('cont.helmert' should be 'contr.helmert').
Thanks, I've fixed the typo. Duncan Murdoch