Limiting a data set and comparing subsamples in MIXED

SH1125 — Mon, 28 Apr 2014 21:53:11 GMT

1) Did I write this coding correctly? I'm running a CRD with subsamples. Fixed variables: Treatment and Rows(Treatment). Random variables Phenology.

2) I collected subsamples over three years but the years should not be pooled. How can I ask SAS to analyze only one year without altering my data set by hand?

3) How can I ask SAS to compare each row within each treatment and phenology but not between them? For example, I would like to compare 'Phenology Lvl 1, Trt Lvl 1, Row Lvl 1' vs. 'Phenology 1, Trt 1, Row 2' but I do not want to view 'Phenology 1, Trt 1, Row 1' vs. 'Phenology 2, Trt 2, Row 1.'

PROC MIXED DATA = Abundance3Year METHOD = TYPE3;

CLASS TREATMENT RowOrder PhenologyRef;

MODEL PairsRecovdRate = RowOrder(Treatment);

RANDOM PhenologyRef PhenologyRef*Treatment;

LSMEANS RowOrder(Treatment) / PDIFF;

RUN; QUIT;

Thanks for your help.

Re: Limiting a data set and comparing subsamples in MIXED

SteveDenham — Tue, 29 Apr 2014 12:57:15 GMT

1. Ought to work. I'm more used to the usual notation of A*B, rather than A(B) for the model and lsmeans statements, but they should work. I am curious why you would use type3 analysis rather than the default REML with this design, though.

2. A BY statement would give separate analyses by year. Be sure the data are sorted appropriately.

3. But phenology is a random effect, so if you want to do this, you will have to construct ESTIMATE statements to compare the BLUPs at each phenology. This could become tedious.

Steve Denham

topic Limiting a data set and comparing subsamples in MIXED in Statistical Procedures

Limiting a data set and comparing subsamples in MIXED

Re: Limiting a data set and comparing subsamples in MIXED