Bioequivalence and Bioavailability Forum • Proc MIXED

Proc MIXED - start value [Software]

posted by ElMaestro – Denmark, 2014-10-11 23:18 (3860 d 22:10 ago) – Posting: # 13689
Views: 38,584

Hi Yung-jin,

(if I may chime in)

❝ However, I still wonder how to set it up. Could you share the results (incl. codes) here with and without PARMS option to run PROC MIXED here? I don't have SAS and dataset to try this. :-D I was wondering the PARMS is for the fixed effects and random effects (the model), not for the covariance parameters.

❝ ❝ The PARMS statement specifies initial values for the covariance parameters, or it requests a grid search over several values of these parameters. ..."

Means: The PARMS statement gives you control of starter values for the random effects - these are the covariances.

❝ I did find that there is an option (start) in nlme(). This start option is an optional numeric vector, or list of initial estimates for the fixed effects and random effects. If declared as a numeric vector, it is converted internally to a list with a single component fixed, given by the vector. The fixed component is required, unless the model function inherits from class selfStart, in which case initial values will be derived from a call to nlsList....

❝

❝ So I don't think that this option (start) is for setting the initial values of covariance parameters.

This is a bit mumbojumbo. As above, inits for the random effects might be what you are looking for but I don't know is meant by the list with a single component fixed.

—
Pass or fail!
ElMaestro

Complete thread:

reference dataset elba.romero 2013-07-02 05:08 [Software]
- Public datasets Helmut 2013-07-02 15:44
  - Public datasets yjlee168 2013-07-03 03:10
    - Public datasets elba.romero 2013-07-03 05:19
      - Public datasets yjlee168 2013-07-03 13:11
        
        Challenging data sets Helmut 2013-07-03 16:32
        
        Fantastic idea? ⇒ Challenging data sets yjlee168 2013-07-04 08:06
        
        Fantastic idea! Helmut 2013-07-04 13:18
    - NIST; cross-validation Helmut 2013-07-03 14:28
      - NIST; cross-validation yjlee168 2013-07-03 23:47
        
        NIST; cross-validation Helmut 2013-07-04 00:45
  - Public datasets elba.romero 2013-07-03 05:10
- Eight Reference Datasets (2×2×2 ☑) Helmut 2014-10-06 02:24
  - What??? ElMaestro 2014-10-06 13:20
    - What??? Helmut 2014-10-06 17:08
      - What??? ElMaestro 2014-10-06 17:31
        
        What the heck‽ Helmut 2014-10-06 19:05
  - link of electronic supplement material? yjlee168 2014-10-07 09:53
    - link of electronic supplement material? nobody 2014-10-07 10:59
      - Thanks! yjlee168 2014-10-07 11:35
        
        Thanks! nobody 2014-10-07 11:44
        
        Direct links & hint Helmut 2014-10-07 13:54
    - Replicated designs are relevant, too ElMaestro 2014-10-07 12:36
      - Replicated designs are relevant, too yjlee168 2014-10-07 13:00
        
        RSABE: SAS and PHX/WNL only? Helmut 2014-10-07 14:47
        
        for the future? yjlee168 2014-10-08 10:05
        
        Star Trek: The Next Generation Helmut 2014-10-09 00:26
        
        Star Trek: The Next Generation d_labes 2014-10-09 08:09
        Star Trek: The Next Generation nobody 2014-10-09 08:23
        Star Trek: The Next Generation yjlee168 2014-10-09 11:06
        
        Some comments ElMaestro 2014-10-09 11:52
        
        Some comments yjlee168 2014-10-09 12:18
        
        Proc MIXED - start value d_labes 2014-10-10 08:35
        
        Proc MIXED - start value ElMaestro 2014-10-10 11:44
        Proc MIXED - start value yjlee168 2014-10-11 21:09
        
        Proc MIXED - start valueElMaestro 2014-10-11 21:18
        
        Optimizer settings Helmut 2014-10-09 14:08
        
        Optimizer settings nobody 2014-10-09 15:32
        Optimizer settings yjlee168 2014-10-09 18:14
        
        FDA’s model… Helmut 2014-10-09 18:34
  - Just received a letter… Helmut 2014-11-03 14:54
  - 11 Reference Datasets (2-group parallel ☑) Helmut 2014-12-09 15:51