bear v1.0.0 for R - first impressions [🇷 for BE/BA]

posted by yjlee168 Homepage – Kaohsiung, Taiwan, 2008-07-14 12:26 (5758 d 17:56 ago) – Posting: # 2022
Views: 56,666

Dear HS,

Thank you for your testing.

❝ I had a quick view already, some first impressions below:

❝ – The plots for selection of data points in NCA should be in semilog scale rather than linear.


Definitely. You're correct! We will change this asap.

❝ – Maybe it’s possible to open only one graphics device and turn the history on - instead of opening a new device for every plot.


For cleaning reason on the screen, the plots should be displayed as you suggested. We will try and see if it can be done.

❝ – In sample size estimation you should consider rounding up to the next even number:

❝ Example:

❝ For 20% CV, theta 95%, power 80% bear comes up with:

❝ --------------------------------------------------------------------------

❝                                <<Suggestion>>

❝ --------------------------------------------------------------------------

❝              n>= 9.13  (sample size number for per sequence)

❝             Total sample size 18

❝ --------------------------------------------------------------------------

❝ I implemented Hauschke’s approximation in Excel (sorry, a quick shot) and obtained:

❝ 9.1763 / sequence = 18.3526 / total -> rounded up to next even number = 20

❝ David Dubins’ FARTSSIE comes up with 19 / total

❝ StudySize2.01: 9.1876 / sequence = 18.3752 / total

❝ My R-code (modified from Patterson’s/Jones’ SAS) would give a total of 20 (power 83.47%).

❝ With bear’s suggested n=18 I got power of only 79.1% (StudySize).


Yes, we should not use rounding up. It should be 20 when we have estimated sample size of 18.3. It will be fixed in the next release.

❝ I failed in reading in the NCA test file. I tried it with tabulator and

❝ semicolon as field separators and got an error:

❝ Error in readChar(con, 5L, useBytes = TRUE) :

❝   cannot open connection


We have not tested with a .csv file using semicolon(;) before. Please try with comma(,) to see if it can work normally. I just tried with semicolon as field separator, it can cause error.

❝ – I would avoid the term "Tests of Hypothese using the Type I MS for

❝ SUBJECT(SEQUENCE) as an error term" and use "Tests of

❝ Hypothesis for SUBJECT(SEQUENCE) as an error term" instead. There were some discussions on the R-list and here also about Types I-III; don’t fall into the trap of using SAS’ proprietary terminology… ;-)


Of course. will be fixed, too.

❝ - IMHO a posteriori power is meaningless.


Just for the purpose of submission to regulatory agent (at least in Taiwan).
However, you're absolutely right.

❝ Two points for the wishlist:

❝ – CVintra and CVinter

❝ – intra-subject residuals - something everybody misses in WinNonlin…


These seems not so difficult to implement. We will add these as you suggest.

❝ Again, many thanks; I will continue testing - time allowing.


Thank you so much, HS.

Best regards,
Yung-jin Lee
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