LSMEANS Statement
 LSMEANS effects < / options > ;
The LSMEANS statement computes leastsquares means (LSmeans)
corresponding to the specified effects for the linear predictor
part of the model.
The L matrix constructed to compute them is
precisely the same as the one formed in PROC GLM.
The LSMEANS statement is not available for multinomial distribution
models for ordinal response data.
Each LSmean is computed as , where L is
the coefficient matrix associated with the leastsquares mean and
is the estimate of the parameter
vector. The approximate standard errors for
the LSmean is computed as the square root of .
LSmeans can be computed for any effect in the MODEL statement that
involves CLASS variables. You can specify multiple effects in one
LSMEANS statement or multiple LSMEANS statements, and all LSMEANS
statements must appear after the MODEL statement.
As in the
ESTIMATE statement, the L matrix is tested for estimability, and
if this test fails, PROC GENMOD displays "Nonest" for the LSmeans
entries.
Assuming the LSmean is estimable, PROC GENMOD constructs a
Wald chisquare test to test the null hypothesis that the
associated population quantity equals zero.
You can specify the following options in the LSMEANS statement
after a slash (/).
 ALPHA=number

requests that a confidence interval be constructed for
each of the LSmeans with confidence level
(1  number)×100%.
The value of number must be between 0 and 1;
the default value is 0.05,
corresponding to a 95% confidence interval.
 CL

requests that confidence limits be constructed for each
of the LSmeans. The confidence level is 0.95 by default; this can
be changed with the ALPHA= option.
 CORR

displays the estimated correlation matrix of the LSmeans
as part of the "Least Squares Means" table.
 COV

displays the estimated covariance matrix of the LSmeans
as part of the "Least Squares Means" table.
 DIFF

requests that differences of the LSmeans be displayed.
All possible differences of LSmeans, standard errors,
and a Wald chisquare test are computed. Confidence limits
are computed if the CL option is also specified.
 E

requests that the L matrix coefficients for all LSMEANS effects
be displayed.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.