Bioequivalence and Bioavailability Forum

loop ↔ vectorized ↔ direct [Two-Stage / GS Designs]

posted by ElMaestro  – Denmark, 2017-08-20 17:22 (2863 d 07:22 ago) – Posting: # 17721
Views: 30,002

Hi Hötzi,

❝ Later down you makes calls to vecQT1[df] and vecQT2[df]. That’s awfully sl^oo_ow. Why not simply call qt(p=foo, df=bar) directly?

That kind of benchmarking is misleading. Here you are doing the vectorise operation of array generation numerous times which will never happens in practice; you only need to initialise the arrays once within every run of 1000000 iterations, possible even keep the arrays/vectors across runs.

I agree that whole "once" operation is faster when you use
vecQT1 <- qt(p=1-alpha1, df=1:5000)
(I had no idea you could do that, actually)
, but if you benchmark the entire you you will see the difference may be a few microsecs out of numerous seconds or minutes. Saving 0.0001% time? That's not optimization, it beautification or achieving the same with fewer lines of code which isn't what I am after.

I am not very experienced with vectorised functions at all - I understand code better if loops are visible. That's just me, of course.

Complete thread:

• Initial sample size guess for the Potvin methods ElMaestro 2017-08-19 15:04 
  • Initial sample size guess for the Potvin methods Helmut 2017-08-19 16:06
    • Initial sample size guess for the Potvin methods ElMaestro 2017-08-19 16:14
      • Initial sample size guess for the Potvin methods Helmut 2017-08-19 17:12
        • Initial sample size guess for the Potvin methods ElMaestro 2017-08-19 17:17
          • Confuse-a-Cat Helmut 2017-08-19 17:33
            • Confuse-a-Cat ElMaestro 2017-08-19 17:56
      • loop ↔ vectorized ↔ direct Helmut 2017-08-20 14:40
        • loop ↔ vectorized ↔ directElMaestro 2017-08-20 15:22
          • loop ↔ vectorized ↔ direct Helmut 2017-08-20 16:23
            • loop ↔ vectorized ↔ direct ElMaestro 2017-08-20 17:22
  • The n ext crackpot iteration ElMaestro 2017-08-19 20:04
    • The n ext crackpot iteration Helmut 2017-08-20 02:20
  • The ultimate crackpot iteration! ElMaestro 2017-08-20 14:35
    • The ultimate crackpot iteration! Helmut 2017-08-20 15:11
      • The ultimate crackpot iteration! ElMaestro 2017-08-20 15:28
        • The ultimate crackpot iteration! Helmut 2017-08-20 16:06
          • The ultimate crackpot iteration! ElMaestro 2017-08-20 16:15
            • The ultimate crackpot iteration! Helmut 2017-08-20 18:58
              • The ultimate crackpot iteration! ElMaestro 2017-08-20 19:32
                • Suggested code ElMaestro 2017-08-21 18:13
                  • Nitpicker! Helmut 2017-08-22 13:33
                    • Nitpicker! ElMaestro 2017-08-22 17:27
                      • Nitpicker! Helmut 2017-08-22 17:49
                        • Nitpicker! ElMaestro 2017-08-22 17:59
                          • Nitpicker! Helmut 2017-08-22 19:15
                            • Benchmark code ElMaestro 2017-08-22 22:29
                              • Benchmark code Helmut 2017-08-23 01:48