Huge gap in my understanding [General Sta­tis­tics]

posted by martin  – Austria, 2018-03-06 15:40 (2533 d 04:42 ago) – Posting: # 18498
Views: 5,561

Dear ElMaestro,

You may have a look at R package lsmeans for more details and this R code may help (credits to Alex) in understanding.

library(lsmeans)

### Covariance example (from Montgomery Design (8th ed.), p.656)
print(fiber)

### model
fiber.lm <- lm(strength ~ diameter + machine, data = fiber)
summary(fiber.lm)

# means versus ls-means
fiber$pred <- predict(fiber.lm, list(machine=fiber$machine, diameter=rep(mean(fiber$diameter), 15)))
aggregate(fiber$strength, by=list(fiber$machine), mean) # mean
aggregate(fiber$pred, by=list(fiber$machine), mean)     # lsmean

# lsmeans via R package lsmeans
fiber.lsm <- lsmeans(fiber.lm, "machine")
fiber.lsm

Complete thread:

UA Flag
Activity
 Admin contact
23,379 posts in 4,913 threads, 1,661 registered users;
269 visitors (0 registered, 269 guests [including 18 identified bots]).
Forum time: 20:22 CET (Europe/Vienna)

Science is what you know.
Philosophy is what you don’t know.    Bertrand Russell

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5