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Re: how to seperate array after a certain number of elements?

by artist (Parson)
on Sep 19, 2007 at 15:51 UTC ( [id://639914]=note: print w/replies, xml ) Need Help??


in reply to how to seperate array after a certain number of elements?

Here is the iterator approach. ( N at a time) 
use List::MoreUtils qw(natatime);

my @myArray = (1..100);
my @myMainArray = ();
my $chunkSize = 5;

my $iterator = natatime $chunkSize, @myArray;
while(my @values = $iterator->()){
  push @myMainArray, [@values];
}
foreach  (@myMainArray){
  my @smallArray = @{$_};
  print "@smallArray\n";
}

[download]
Here is a 'hacked' approach using 'part'. 
use List::MoreUtils qw(part);
@array = (1..100);
$i = -0.1;
@parts = part { $i += 0.2   }  @array;

[download]
--Artist

Replies are listed 'Best First'.
Re^2: how to seperate array after a certain number of elements?
by ikegami (Patriarch) on Sep 20, 2007 at 19:53 UTC

    It's dangerous to repeatedly add decimal numbers since many of them are periodic in binary and therefore cannot be stored precisely. This includes 0.2.

    >perl -le"printf '%.17f', .2
0.20000000000000001

    [download]

    The following is a safer, simpler and easier to read (since "5" actually appears) version of your second snippet:

    use List::MoreUtils qw(part);
my @array = (1..100);
my $i; my @parts = part { ($i++)/5 } @array;

    [download]
[reply]
[d/l]
[select]
      Thanks, I never knew the reason behind it. Very useful tip.
      --Artist
[reply]
[d/l]

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