#!/usr/bin/perl

use Benchmark;

sub logbase1 {                # Compute the value each time.
    my ($base, $numbers) = @_;
    my @result;
    for (my $i = 0; $i < @$numbers; $i++) {
        push @result, log ($numbers->[$i]) / log ($base);
    }
    return @result;
}

sub logbase2 {                # Store log $base in a temporary variable.
    my ($base, $numbers) = @_;
    my @result;
    my $logbase = log $base;
    for (my $i = 0; $i < @$numbers; $i++) {
        push @result, log ($numbers->[$i]) / $logbase;
    }
    return @result;
}

@numbers = (1..1000);

timethese (1000, { no_temp => 'logbase1( 10, \@numbers )',
                   temp => 'logbase2( 10, \@numbers )'  });