The four drug-by-dose means of ex125 (25.45, 24.28, 21.48 and 17.13) and their variance 1.27,
as least-squares means.
References
Duchateau, L., Janssen, P. and Rowlands, G. J. (1998). Linear Mixed Models. An Introduction with Applications in Veterinary Research. International Livestock Research Institute, Nairobi.
See also
Other VetResearchLMM examples:
Examp1.3.2,
Examp2.2.1.7,
Examp2.3.2,
Examp2.4.2.2,
Examp2.4.3.1,
Examp2.5.1.1,
Examp2.5.3.1,
Examp2.5.4.1,
Examp2.6.1,
Examp3.1,
Examp3.2,
Examp3.3
Author
Muhammad Yaseen (myaseen208@gmail.com)
Examples
# SAS program of the book (Appendix B):
# proc mixed data=ex125;
# class drug dose region;
# model pcv = drug dose drug*dose;
# random region drug*region;
# lsmeans drug*dose;
# run;
fm <-
vlm_fit(
fixed = Pcv ~ Drug + dose + Drug:dose
, data = ex125
, random = ~ Region + Region:Drug
, repeated = NULL
, method = "REML"
, ddfm = "default"
, type = 3
, class = NULL
, bound = TRUE
, control = list()
)
vlm_lsmeans(
fit = fm
, specs = ~ Drug:dose
, at = NULL
, diff = FALSE
, adjust = "none"
, level = 0.95
)
#> Least-squares means (denominator df: contain; 95% limits)
#>
#> Least squares means
#> Drug dose estimate se df t p lower upper
#> BERENIL h 25.45 1.128 10 22.56 <1e-04 22.94 27.96
#> BERENIL l 24.28 1.128 10 21.53 <1e-04 21.77 26.80
#> samorin h 21.48 1.128 10 19.05 <1e-04 18.97 24.00
#> samorin l 17.13 1.128 10 15.19 <1e-04 14.62 19.65
#>
#> Sources: Duchateau, Janssen and Rowlands (1998); Searle, Speed and Milliken
#> (1980). Full references: vlm_cite(x).