Bioequivalence and Bioavailability Forum • SAS -> R -> SAS

SAS -> R -> SAS [🇷 for BE/BA]

posted by Helmut – Vienna, Austria, 2009-10-05 16:53 (5738 d 12:54 ago) – Posting: # 4297
Views: 34,207

Dear D Labes,

❝ Implementing the Julious formulas (according to Helmut's R-code) in "The power to know" results in power=-0.027799235, same as Fartssie!

Funny!
My R-code was just ported from Patterson's/Jones' SAS-code. Tweaking the code to calculate power (haha) at n=38:

options(digits=8)

alpha  <- 0.05; CV <- 0.65; ratio <- 0.95; n <- 38

Theta1 <- 0.80; Theta2 <- 1/Theta1

s      <- sqrt(2)*sqrt(log(1+CV^2))

t1     <- qt(1-alpha,n-2)

nc1    <- sqrt(n)*(log(ratio)-log(Theta1))/s

nc2    <- sqrt(n)*(log(ratio)-log(Theta2))/s

prob1  <- pt(+t1,n-2,nc1)

prob2  <- pt(-t1,n-2,nc2)

power  <- prob2-prob1

power

I get -0.027799235, which is either an Ouroboros or another strong hint that SAS and R follow the same algorithm.

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz

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Complete thread:

non-central t, power, R: ElMaestro 2009-10-03 19:05
- non-central t, power, R: Helmut 2009-10-03 21:45
  - non-central t, power, R: ElMaestro 2009-10-04 21:51
    - non-central t, power, R: Helmut 2009-10-04 23:58
- non-central t is not the question d_labes 2009-10-05 12:58
  - SAS -> R -> SASHelmut 2009-10-05 14:53
    - Lost in translation d_labes 2009-10-06 14:31
      - Lost in translation Helmut 2009-10-06 14:42
        
        Macacus cynocephalus d_labes 2009-10-06 15:14
        
        Lost in translation Helmut 2009-10-06 21:46
  - non-central t is not the question ElMaestro 2009-10-05 17:32
    - Power of TOST in R d_labes 2009-10-06 16:45
      - Power of TOST (R package MBESS) Helmut 2009-10-07 02:18
        
        Power of TOST (R package MBESS) d_labes 2009-10-07 08:46
        
        Power of TOST (R package MBESS) Helmut 2009-10-07 12:38
      - The Power at limits d_labes 2009-10-07 11:32
        
        Power at limits 2 d_labes 2009-10-07 15:15
        
        package MBESS Helmut 2009-10-07 22:36
        
        Package MBESS and Power curiosity d_labes 2009-10-15 14:57
        
        Package MBESS and Power curiosity ElMaestro 2009-10-17 12:26
        
        Apfelstrudel and EFG 2.01 Helmut 2009-10-17 13:44
        EFG and another power curiosity d_labes 2009-10-20 11:35
        
        EFG and another power curiosity ElMaestro 2009-11-23 19:03
        
        EFG and another power curiosity Helmut 2009-11-23 19:17
- non-central t, power, R: yjlee168 2009-10-07 00:08
  - PASS Helmut 2009-10-07 01:16
    - PASS yjlee168 2009-10-12 23:17
- R code for power ElMaestro 2009-10-09 11:32
  - Belgian beer ? Ohlbe 2009-10-09 11:50
  - Another one - R code for power of TROST d_labes 2009-10-09 13:50