Bioequivalence and Bioavailability Forum • Mean as intercept; model matrices

Mean as intercept; model matrices [🇷 for BE/BA]

posted by yjlee168 – Kaohsiung, Taiwan, 2009-05-23 22:06 (6225 d 18:54 ago) – Posting: # 3741
Views: 14,061

Dear ElMaestro,

I don't quite understand the link that you mentioned in this post. So it's called "contrast coding"? And what you do mean about '...principle of summing to zero...'? We have already known that SPSS, SAS, and now R have different coding policy for dummy variables. Thanks, EM.

❝ It appears that options(contrasts = c("contr.helmert",

❝ "contr.poly")) does the trick, then the model fits the mean as

❝ intercept. I got the inspiration for this here. Let it be said, I am

❝ not totally comfortable with contrasts (or with BE or with R or ...)

—
All the best,
-- Yung-jin Lee
bear v2.9.6:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan https://www.pkpd168.com/bear
Download link (updated) -> here

Complete thread:

Mean as intercept; model matrices ElMaestro 2009-05-20 20:35
- Mean as intercept; model matrices yjlee168 2009-05-21 13:35
  - Mean as intercept; model matrices ElMaestro 2009-05-21 14:30
- Mean as intercept; model matrices ElMaestro 2009-05-22 14:39
  - Mean as intercept; model matricesyjlee168 2009-05-23 20:06
  - Mean as intercept; model matrices Aceto81 2009-05-26 10:28
- Mean as intercept; model matrices yjlee168 2009-05-23 19:30
  - Mean as intercept; model matrices ElMaestro 2009-05-23 19:53
- Reparameterization d_labes 2009-05-25 11:47
  - Reparameterization yjlee168 2009-05-25 14:17
  - Reparameterization ElMaestro 2009-05-25 20:29
    - Reparameterized brain d_labes 2009-05-26 08:01