Bioequivalence and Bioavailability Forum

Huge gap in my understanding [General Statistics]

posted by martin – Austria, 2018-03-06 15:40 (2241 d 21:54 ago) – Posting: # 18498
Views: 4,872

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:

LSMeans ElMaestro 2018-02-27 09:02
- Understanding (!) LSMeans d_labes 2018-02-28 09:49
- Huge gap in my understanding ElMaestro 2018-03-04 10:03
  - Huge gap in my understandingmartin 2018-03-06 14:40
    - Huge gap in my understanding ElMaestro 2018-03-06 17:30
      - Huge gap in my understanding martin 2018-03-06 19:58
        
        Huge gap in my understanding ElMaestro 2018-03-06 20:53
        
        Huge gap in my understanding martin 2018-03-07 08:42

Huge gap in my understanding [General Sta­tis­tics]

Complete thread:

Huge gap in my understanding [General Statistics]