update: bear v1.1.4 for R (a free tool for ABE) [🇷 for BE/BA]

posted by yjlee168 Homepage – Kaohsiung, Taiwan, 2008-09-23 12:07 (6478 d 02:50 ago) – Posting: # 2386
Views: 26,599

Dear martin,

The lee function from package PK (for R) seems not working correctly. We tried several examples here and found the result weird. The code we used to test and the result we obtained is shown as follow (one of tested examples).
> ##1 example for preparation 1 from Lee et al. (1990)
> time <- c(0.5, 1.0, 4.0, 8.0, 12.0, 24.0)  # truncated dp before Tmax
> conc <- c(75, 72, 61, 54, 36, 6)           # truncated dp before Tmax
> result1 <- lee(conc=conc, time=time, method='ols', points=2, lt=TRUE)
> print(result1$parms)
              initial    terminal
halflife   6.59747708  6.59747708
slope     -0.04562805 -0.04562805
intercept  1.97385991  1.97385991

And its plot of the regression line is like this:
[image]
Interesting to find that lee function seems to take all data points to estimate lambdaz with the subset data. Looked like that lee function cannot pick up appropriate data points to estimate lambdaz (or half-lives). Apparently, lee function doesn't meet our needs.
—
All the best,
-- Yung-jin Lee
bear v2.9.6:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan https://www.pkpd168.com/bear
Download link (updated) -> here

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