Bioequivalence and Bioavailability Forum • V

V [🇷 for BE/BA]

posted by ElMaestro – Denmark, 2011-01-28 13:14 (5203 d 20:43 ago) – Posting: # 6507
Views: 66,712

Dear d_labes,

❝ where are the intra-individual (error or residual) variances or sd for Test and Reference?

❝ You have only one residual.

❝ The trt1 and trt2 variances (and corr) in your output are the between subject covariance parameter.

Interesting. Let us discuss for a moment the covariance matrix V (not Z and not G, and at this point also not discussing which syntax SAS applies for the given problem (leaves disussions about CSH, FA(0) out here)).
V holds the key.
Further, let us assume for simplicity we only look at the first subject which is the first 4x4 of V where the data are ordered as TRTR (i.e. per1-per2-per3-per4 for the first subject; in the original dataset above they were ordered differently but the order in this context does not change the point):

Data in per1 and per3 correlate within the subject as (s)he gets T (within variance VT).
Data in per2 and per4 correlate within the subject as (s)he gets R (within variance VR).
To this we add a common error variance on the diagonal (V0).

Having no particular mathematical understanding, the first 4x4 of V I think will be:

V0+VT     0         VT       0

0         V0+VR     0        VR

VT        0         V0+VT    0

0         VR        0        V0+VR

Both of the models discussed above correspond to a fit with this V, as far as I can see.

—
Pass or fail!
ElMaestro

Complete thread:

Freedom for replicate bears d_labes 2009-04-17 12:06
- Freedom for replicate bears ElMaestro 2009-04-17 14:50
  - Contain does not contain d_labes 2009-04-17 15:07
- Freedom for replicate bears ElMaestro 2009-04-18 03:45
  - Freedom incompatible with baseball bats d_labes 2009-04-20 08:42
- Freedom for replicate bears yjlee168 2009-04-19 21:38
  - Freedom to some degree d_labes 2009-04-20 08:30
    - Freedom to some degree yjlee168 2009-04-21 14:03
      - FDA loves replicate bears? d_labes 2009-04-21 16:11
        
        Cholesky factor ?! Helmut 2009-04-22 00:46
        
        Cholesky factor ?! d_labes 2009-04-22 11:20
        
        FDA loves replicate bears? yjlee168 2009-04-23 08:08
        
        FDA loves SAS code? d_labes 2009-04-23 09:48
        
        FDA loves SAS code? definitely. yjlee168 2009-04-23 10:46
        
        SAS? or R? or what? d_labes 2009-04-23 15:07
        
        SAS? or R? or what? Helmut 2009-04-23 15:25
        
        SAS? or R? or what? d_labes 2009-04-23 16:06
        
        SAS? or R? or what? Helmut 2009-04-23 16:30
        
        SAS? YES; R? why not? as long as they are useful... yjlee168 2009-04-23 19:56
        
        New Forum-Category 'bear'? Helmut 2009-04-23 20:03
        
        New Forum-Category 'bear'? yjlee168 2009-04-23 20:19
        
        New Forum-Category 'R for BE/BA' Helmut 2009-04-23 20:37
        
        New Forum-Category 'R for BE/BA' yjlee168 2009-04-24 09:19
        
        Replicated again d_labes 2009-04-24 08:27
        
        Replicated again yjlee168 2009-04-24 09:26
- getting decimals ElMaestro 2010-06-03 05:21
  - getting decimals yjlee168 2010-06-03 08:37
    - getting decimals ElMaestro 2010-06-04 01:59
- Freedom for replicate bears ElMaestro 2011-01-27 21:50
  - lmer vs. lme d_labes 2011-01-28 09:02
    - lmer vs. lme ElMaestro 2011-01-28 09:42
      - lmer vs. lme d_labes 2011-01-28 11:37
        
        VElMaestro 2011-01-28 12:14
        
        V corrected d_labes 2011-01-28 14:12
        
        V corrected ElMaestro 2011-01-28 15:20
        
        Peculiar partial replicate d_labes 2011-01-28 16:10