I guess I should provide some real code.
below is a tiny module I grabbed from my project which is not that privacy
but sufficient for discussion.
#/usr/bin/perl
use warnings;
use 5.010;
use Carp;
use DB_File;
{
my %sum_cache;
my %deviation_cache;
tie %sum_cache => 'DB_File', "sum_cac
OK, I think I got the idea.
I am going to change the useless code caching the result I have already
summed or inline c code to achieve a better performance. Really learned
something. Thank you!
I know I am doing the repetitive and useless summing again and again. What
confuses me is that using the same algorithm, I mean
for my $i (99 .. 6)
{
my $sum;
map {$sum += $_->{foo_value}} @lines[$i - $n + 1 .. $i];
push @res, $sum;
}
in perl and
for(int i =99; i <= 6;
Thanks for your help!
I am sorry I missed something important in the code snippet.
for($i = 0; $i < @lines; $i++)
{
$sum = 0;
$sum += $lines[$_]->{foo_value} for ($i - $n + 1 .. $i);
push @res, $sum;
}
this is what I intend.I try to make it clear and removed something so that
change
Hi all:
I translated a program from c to perl.but the perl program cost 15 seconds
compare to the original c one cost only less than 1 second, I guess this
might be the result of I literally translated the program, using a lot of
array subscripts. After I profile the perl program, it turned out my
