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The K/VW benchmarks were originally made for C and seem to test looping controls and memory allocation which at a time of low memory minicomputers and PCs, coupled with multiple available C compilers,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
NB. Kernighan/Van Wyk benchmarks in J NB. Missing the tail benchmark load 'tables/dsv' NB. sumloop NB. loop to sum by incrementing in a loop NB. done in non-J way sumloop =: 3 : 0 sum =. 0 for_i. i. y do. sum =. sum + 1 end. sum ) NB. sumj NB. sum consecutive integers as in J sumj =: 13 : '+/ y$1' NB. ackerman functon in J NB. implementation from Jsoftware essays: NB. https://code.jsoftware.com/wiki/Essays/Ackermann's_Function ack=: c1`c1`c2`c3 @. (#.@,&*) M. c1=: >:@] NB. if 0=x, 1+y c2=: <:@[ ack 1: NB.s if 0=y, (x-1) ack 1 c3=: <:@[ ack [ ack <:@] NB. else, (x-1) ack x ack y-1 NB. array1 benchmark NB. fills 2 arrays with consequtive integers NB. one in ascending order and one in decending order array1 =: 3 : 0 (i.y); i.(-y) ) NB. as tacit definition array1t =: 13 : '(i.y);i.(-y)' NB. string1 NB. grows a string from 'abcedf' until it reaches NB. the size given by the y input parameter NB. then releases it and does it again 10 times string1 =: 3 : 0 for_i. i. 10 do. s =. 'abcdef' while. (#s) <: y do. p =.'123',s,'456',s,'789' s =. p len =. #s p =. (-<.len%2){.s s =. p,(1+<.len%2){.s end. end. #s ) NB. cat benchmark NB. copies a file NB. x - input file NB. y - output file NB. the usual test is to download the King James Version of the bible NB. in text (UTF-8) format and make a copy of it NB. in the Benchmark function below this is placed in ~temp (J user dir) cat =: 4 : 0 (freads x) fwrites y ) NB. wc benchmark NB. read a file output character count, word count and line count wc =: 3 : 0 z =. freads y lc =. +/ LF = z NB. there are Carriage Return characters in the file string NB. they will show up as words so I remove them from the string wordc =. # ; cut each LF&cut CR&(-.~)z lc;wordc;#z ) NB. sum1 benchmark NB. read from a file 100000 floating point numbers and sum them sum1 =: 3 : 0 +/ ,makenum readdsv 'randfloats.dsv' ) NB. sum1j benchmark NB. original C is to read from a file a list of random floating point NB. values NB. In this J version I create my own numbers in program sum1j =: 3 : 0 nums =. ?y$0 +/nums ) NB. benchmarks NB. the test bench for collected routines benchmarks =: 3 : 0 smoutput 'sumloop: ',":timespacex 'sumloop 1000000' smoutput 'sumj: ',":timespacex 'sumj 1000000' smoutput 'ack: ',":timespacex '3 ack 8' NB. asignment used in array call as that is part of the test smoutput 'array1: ',": timespacex '''ip jp''=: array1 50000' smoutput 'array1t: ',": timespacex '''ip jp''=: array1t 50000' smoutput 'string1: ', ":timespacex 'string1 500000' smoutput 'cat: ', ":timespacex '''~temp/KJVGut.txt'' cat ''~temp/KJV1.txt''' smoutput 'wc: ', ":timespacex 'wc ''~temp/KJVGut.txt''' smoutput 'sum1: ', ": timespacex 'sum1 100000' smoutput 'sum1j: ', ":timespacex 'sum1j 100000' ) NB. make a file with y random floating point numbers NB. will use dsv addon for this makeRFloat =: 3 : 0 rfloats =. (? y$500)+(? y $ 0) rfloats writedsv '~temp/randfloats.dsv' )
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