From: Reid Thompson <reid.thompson@...>
Date: 2009-02-11T13:43:04+09:00
Subject: Re: Ruby vs Perl performance

William James wrote:
> Reid Thompson wrote:
> 
>> Reid Thompson wrote:
>>> Ruby Elapsed 0.045477
>>>
>>>
>> #!/usr/local/bin/ruby
>>
>> require 'rubygems'
>> require 'inline'
>>
>> BAILOUT = 16
>> MAX_ITERATIONS = 1000
>>
>> class Mandelbrot
>>
>>      def initialize
>>          puts "Rendering"
>>          for y in -39...39 do
>>              puts
>>              for x in -39...39 do
>>                  i = iterate(x/40.0,y/40.0)
>>                  if (i == 0)
>>                      print "*"
>>                  else
>>                      print " "
>>                  end
>>              end
>>          end
>>      end
>>
>>      inline do |builder|
>>          builder.c "
>>          int iterate (double x, double y)
>>          {
>>              int BAILOUT = 16;
>>              int MAX_ITERATIONS = 1000;
>>              double cr = y-0.5;
>>              double ci = x;
>>              double zi = 0.0;
>>              double zr = 0.0;
>>              double zr2 = 0.0;
>>              double zi2 = 0.0;
>>              int i = 0;
>>              double temp = 0.0;
>>
>>              while (1)
>>              {
>>                 i += 1;
>>                 temp = zr * zi;
>>                 zr2 = zr * zr;
>>                 zi2 = zi * zi;
>>                 zr = zr2 - zi2 + cr;
>>                 zi = temp + temp + ci;
>>
>>                 if ( zi2 + zr2 > BAILOUT)
>>                 {
>>                     return i;
>>                 }
>>                 if ( i > MAX_ITERATIONS)
>>                 {
>>                     return 0;
>>                 }
>>              }
>>          }"
>>      end
> 
>> end
>>
>>
>> time = Time.now
>> Mandelbrot.new
>> puts
>> puts "Ruby Elapsed %f" % (Time.now - time)
> 
> 
> Using the functional language F#:
> 
> 0.0400575999999999 on my laptop with 2GHz Pentium.
> 

On same box using all C.
Echo delay is 0s and 20842us -> 20842 microseconds = 0.020842 seconds.  This is 
an Intel(R) Core(TM)2 CPU 6320  @ 1.86GHz box w 2GB RAM running gentoo with 
entire system compiled with CFLAGS="-march=prescott -O2 -g -pipe" + feature 
splitdebug ( everything compiled with debug except mandInC ).
-rwxr-xr-x  1 rthompso staff         7104 2009-02-10 23:36 mandInC


time calc code pulled from the web...

rthompso@raker ~ $ cat mandInC.c
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

/**
  * this function is for computing the time difference between timeval x and y
  * the result is stored in result
  */
int
timeval_subtract (struct timeval *result, struct timeval *x, struct timeval *y)
{
     /* Perform the carry for the later subtraction by updating y. */
     if (x->tv_usec < y->tv_usec) {
         int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1;
         y->tv_usec -= 1000000 * nsec;
         y->tv_sec += nsec;
     }
     if (x->tv_usec - y->tv_usec > 1000000) {
         int nsec = (x->tv_usec - y->tv_usec) / 1000000;
         y->tv_usec += 1000000 * nsec;
         y->tv_sec -= nsec;
     }

     /* Compute the time remaining to wait.
     tv_usec is certainly positive. */
     result->tv_sec = x->tv_sec - y->tv_sec;
     result->tv_usec = x->tv_usec - y->tv_usec;

     /* Return 1 if result is negative. */
     return x->tv_sec < y->tv_sec;
}

int iterate (double x, double y)
{
     int BAILOUT = 16;
     int MAX_ITERATIONS = 1000;
     double cr = y-0.5;
     double ci = x;
     double zi = 0.0;
     double zr = 0.0;
     double zr2 = 0.0;
     double zi2 = 0.0;
     int i = 0;
     double temp = 0.0;

     while (1)
     {
         i += 1;
         temp = zr * zi;
         zr2 = zr * zr;
         zi2 = zi * zi;
         zr = zr2 - zi2 + cr;
         zi = temp + temp + ci;

         if ( zi2 + zr2 > BAILOUT)
         {
             return i;
         }
         if ( i > MAX_ITERATIONS)
         {
             return 0;
         }
     }
}

int main()
{
     int y = -39;
     int x = -39;
     int i = -1;
     struct timeval start, stop, echodelay;  // start, stop and echo delay times

     if((gettimeofday(&start, NULL)) == -1)
     {
         perror("gettimeofday");
         exit(1);
     }
     for (y = -39; y <= 39; ++y)
     {
         printf("\n");
         for (x = -39; x <= 39; ++x)
         {
             i = iterate(x/40.0, y/40.0);
             if (i == 0)
                 printf("*");
             else
                 printf(" ");
         }
     }

     if((gettimeofday(&stop, NULL)) == -1)
     {
         perror("gettimeofday");
         exit(1);
     }
     /* compute time delay */
     timeval_subtract(&echodelay, &stop, &start);

     printf("\nEcho delay is %ds and %dus\n", echodelay.tv_sec, echodelay.tv_usec);

     return 0;
}