Re: [R] less than full rank contrast methods

2010-12-07 Thread mxkuhn
Greg and Frank, Thanks for the replies. I didn't express myself very well; I'm not interest in the model fitting aspect. I'd just like to get the full set of dummy variables (optimally from model.matrix) Max On Dec 6, 2010, at 10:29 PM, Frank Harrell f.harr...@vanderbilt.edu wrote: Given

Re: [R] less than full rank contrast methods

2010-12-07 Thread Gabor Grothendieck
'On Tue, Dec 7, 2010 at 5:19 AM, mxkuhn mxk...@gmail.com wrote: Greg and Frank, Thanks for the replies. I didn't express myself very well; I'm not interest in the model fitting aspect. I'd just like to get the full set of dummy variables (optimally from model.matrix) Try this:

Re: [R] less than full rank contrast methods

2010-12-07 Thread Gabor Grothendieck
On Tue, Dec 7, 2010 at 7:54 AM, Gabor Grothendieck ggrothendi...@gmail.com wrote: 'On Tue, Dec 7, 2010 at 5:19 AM, mxkuhn mxk...@gmail.com wrote: Greg and Frank, Thanks for the replies. I didn't express myself very well; I'm not interest in the model fitting aspect. I'd just like to get the

[R] less than full rank contrast methods

2010-12-06 Thread Max Kuhn
I'd like to make a less than full rank design using dummy variables for factors. Here is some example data: when - data.frame(time = c(afternoon, night, afternoon, morning, morning, morning, morning, afternoon, afternoon),

Re: [R] less than full rank contrast methods

2010-12-06 Thread Greg Snow
Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- project.org] On Behalf Of Max Kuhn Sent: Monday, December 06, 2010 8:35 AM To: r-help@r-project.org Subject: [R] less than full rank

Re: [R] less than full rank contrast methods

2010-12-06 Thread Frank Harrell
Given a non-singular fit, the contrast function in the rms package will allow you to request multi-dimensional contrasts some of which are redundant. These singular contrasts are automatically ignored. One use for this is to test for differences in longitudinal trends between two of three