Here's the tail benchmark written in J: tail=: 4 : 0 (;|.<;.2 freads x) fwrites y )
This is based on my reading of the C implementation of the tail benchmark vs the cat benchmark, and on the cat benchmark in this J implementation, except that I have failed to reproduce a bug in the C implementation which shows up when the file contains very long lines and instead I have assumed that the file ends in a newline (which is a valid assumption for the gutenberg kjv bible). Let me know if you think I have made a mistake here. Thanks, -- Raul On Tue, May 18, 2021 at 7:02 PM Thomas McGuire <tmcguir...@gmail.com> wrote: > > I was going over Devon McCormick's notes from the latest NYCJUG meeting. > There was a discussion about Benchmarks with an example of the Kernighan/Van > Wyk benchmarks in LISP/Scheme. Devon had made the comment that for most > things people use J for that correctness overshadowed performance. > > The K/VW benchmarks were originally made for C and seem to test looping > controls and memory allocation which at a time of low memory minicomputers > and PCs, coupled with multiple available C compilers, made the benchmarks a > nice way of comparing compiler implementations as well as new processor speed. > > However it seemed like a simple project to exercise my J programming skills > with so I have attached the program to this email. > > Note: you will need to download the King James Version of the Bible from > project Guttenburg (not included with the attachment) to run the full > benchmarks. I also created my own file of floating point numbers to sum > (routine to create a file of random floats is included). I have added some > routines to accomplish similar functionality in the way I would do it in J > (at least for my mere mortal understanding of J). > > Running on my mac book pro (2016 with 2.9 Ghz Quad core I7) the results are: > > benchmarks '' > sumloop: 0.214383 8.39149e6 > sumj: 0.000162 1.04986e6 > ack: 4e_6 721472 > array1: 0.000578 1.05107e6 > array1t: 2.5e_5 1.05107e6 > string1: 0.003237 2.88634e6 > cat: 0.014234 2.51685e7 > wc: 0.302383 1.58152e8 > sum1: 0.124006 4.04989e7 > sum1j: 0.000956 1.18086e6 > > thought I would share > > Tom McGuire > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
