Handy Loop Timer Script

Hi all, I wrote a loop timer script over the weekend. You can find it on the Ecotope rebsite http://www.nwlink.com/~ecotope1/reb/loop-timer.r For an example, I used the script to examine the speed of simple looping and block access constructs for the kind of tight loops often used in numeric programming, vector-matrix operations, image processing, etc. The script is easily rewritten to create timing tests for your own interests. The example takes about 3 minutes to run at 450MHz, for slower machines you can reduce the ITS variable. My example results for Core and View/Pro (450MHz PII Win98) with some brief comments are given in http://www.nwlink.com/~ecotope1/reb/loop-times.txt One interesting finding was that View is about 3% faster than Core. Some excerpts from the example results are shown below. Enjoy -Larry ---------------------------------------------------- Loop Timer Test Results View/Pro 1.1.0.3.1 Date: 5-May-2001/21:10:28-7:00 Block size: 10000 Loop its: 100 Time Loop Source Code Empty loops 0.11 [loop sz []] 0.11 [repeat j sz []] 0.17 [foreach el x []] 2.21 [j: 1 while [j <= sz] [j: j + 1]] 5.27 [for j 1 sz 1 []] 6.92 [forall x [] x: head x] 7.92 [forskip x 1 [] x: head x] Set and reset current series index 2.42 [loop sz [x: tail x x: head x]] Access all elements of block 0.61 [foreach el x [s: el]] 1.65 [repeat j sz [s: pick x j]] 1.86 [repeat j sz [s: x/:j]] 2.37 [loop sz [s: first x x: next x] x: head x] 2.80 [j: 1 loop sz [s: pick x j j: j + 1]] 4.23 [while [not tail? x] [s: first x x: next x] x: head x] 7.31 [for j 1 sz 1 [s: pick x j]] 8.63 [forall x [s: first x] x: head x] 9.39 [forskip x 1 [s: first x] x: head x] Sum elements of block of numbers 1.53 [s: 0 foreach el x [s: s + el]] 2.53 [s: 0 repeat j sz [s: s + pick x j]] 3.85 [s: 0 j: 1 loop sz [s: s + pick x j j: j + 1]] 3.79 [s: 0 loop sz [s: s + pick x 1 x: next x] x: head x] 8.23 [s: 0 for j 1 sz 1 [s: s + pick x j]] 10.06 [s: 0 forall x [s: s + first x] x: head x]