Bioequivalence and Bioavailability Forum

Multiple peaks: fallback to linear trapezoidal [NCA / SHAM]

posted by yjlee168  – Kaohsiung, Taiwan, 2013-05-22 23:57 (4785 d 00:43 ago) – Posting: # 10622
Views: 24,685

Dear Helmut,

Thank you for your messages and codes. I tried to run your codes without luck, but I will try it later. I will change the way of AUC calculation with bear later. I remembered that I read something about method comparisons for trapezoidal rule in one textbook, but just cannot remember which book.

❝ Not that I am aware of. If values increase again the algo falls back to the linear trapezoidal. Try this clumsy code (a bimodal release formulation with two lag-times, two absorption rate constants and a common elimination):

❝

❝ ...

❝   B1.1   <- C0.1*k01.1/(k01.1-K)*exp(k10*tlag1)

❝   B2.1   <- C0.1*k01.1/(k01.1-K)*exp(k01.1*tlag1)

Here I got Error: object 'K' not found and some error messages after this.

One more question, in your above presentation (slide#17[edited]; missing data occurred in R at 12h), it was a lin-up/log-down plot. As you said that no need to do data imputation if using lin-up/log-down. Do you do any line smoothing with your data first? Otherwise, the line should not be connected in that way. It should be connected as the line that the arrow points. Do I miss anything here?

Complete thread:

• handling of missing data gracehung 2013-05-20 07:35 [NCA / SHAM] 
  • Lin-up/log-down trapezoidal avoids most trouble Helmut 2013-05-20 14:22
    • Lin-up/log-down trapezoidal avoids most trouble yjlee168 2013-05-22 08:25
      • Multiple peaks: fallback to linear trapezoidal Helmut 2013-05-22 20:25
        • Multiple peaks: fallback to linear trapezoidalyjlee168 2013-05-22 21:57
          • No interpolation Helmut 2013-05-22 23:25
            • No interpolation yjlee168 2013-05-23 11:43
              • Spaghetti & other pasta Helmut 2013-05-23 15:15
                • Spaghetti & other pasta yjlee168 2013-05-23 20:47
                  • Spaghetti & other pasta Helmut 2013-05-23 21:29
                    • Spaghetti & other pasta yjlee168 2013-05-23 22:46
                      • Spaghetti & other pasta Helmut 2013-05-24 01:24
                        • Spaghetti & other pasta yjlee168 2013-05-24 09:17
            • No interpolation Ken Peh 2013-05-30 19:55
              • Different algos! Helmut 2013-05-30 22:38
                • Different algos! Ken Peh 2013-06-03 17:52
                  • Calculate what? Helmut 2013-06-03 18:11
      • Lin-up/log-down trapezoidal example Helmut 2013-05-25 15:09
        • Lin-up/log-down trapezoidal example yjlee168 2013-05-25 19:45
  • handling of missing data Ohlbe 2013-05-20 21:45
    • Sorry Helmut 2013-05-21 13:53
      • Sorry gracehung 2013-05-23 01:06
        • Uncertain time point Helmut 2013-05-23 01:35