Re: extracting corresponding values from another array

[thinker]

Hi [Monk},

This should work

#!/usr/bin/perl -w

use strict;

my @temps =  ('69', '70', '71');
my @numbers = ('0.115', '3.667', '4.78');
my $counter=0;
my $index=0;
my $largest=shift @numbers;
for (@numbers){
        $index  = $counter if ($temps[$counter++]>$largest);

}
print $temps[$index];

hope this helps

thinker

Update

I'm sure it won't help, as it doesn't work. Sorry.
Here is a tested :-) version.

#!/usr/bin/perl -w

use strict;

my @temps = ('69', '70', '71');
my @numbers = ('0.115', '3.667', '4.78');

my $index=0;
my $largest=$numbers[0];

for (1 .. $#numbers) {
        if ($numbers[$_] > $largest){
                $largest=$numbers[$_];
                $index=$_;
        }
}
print $temps[$index];

thinker

[Jaap]

You might want to make it a bit clearer, less obfuscated:

my @temps =  ('69', '70', '71');
my @numbers = ('0.115', '3.667', '4.78');
my $highNumberIndex = 0;

for (my $i = 0; $i < @number; $i++)
{
  if ($numbers[$highNumberIndex] < $numbers[$i])
  {
    $highNumberIndex = $i;
  }
}
print $temps[$highNumberIndex];

[demerphq]

You might want to make it a bit clearer, less obfuscated:

Likewise. for(;;) is a dirty C trick that doesnt really belong in perl. Especially when the replacement is easier to understand, less prone to error and most importantly more efficient.

y @temps =  ('69', '70', '71');
my @numbers = ('0.115', '3.667', '4.78');
my $highNumberIndex = 0;

for my $i (0..$#number)
{
  if ($numbers[$highNumberIndex] < $numbers[$i])
  {
    $highNumberIndex = $i;
  }
}
print $temps[$highNumberIndex];

And this isnt a valid solution as if the list is empty we get a false return of 0.

--- demerphq
my friends call me, usually because I'm late....

[Abigail-II]

Likewise. for(;;) is a dirty C trick that doesnt really belong in perl. Especially when the replacement is easier to understand, less prone to error and most importantly more efficient.

Oh, really? A significant part of Perl comes from C, shell, AWK, Ada, BASIC, Python, Fortran, and other languages. Why is for (;;) a dirty C trick that doesn't really belong in Perl, and why isn't for $var (@array) a dirty AWK trick that doesn't belong in Perl? Leave it to the villains of "Harry Potter and the Secret Chamber" to strive for "pure blood".

I also disagree with your other claims. I'm not convinced that the replacement is easier to understand, less prone to error, and more efficient. Let's consider the "dirty C trick":

    for (my $i = 0; $i < 1000000; $i += 2) {$sum += $i}

The AWK-like replacement would be:

    for my $i (map {$_ * 2} 0 .. 1000000 / 2) {$sum += $i}

I don't think that's easier to understand, or less prone to error. As for efficientcy:

#!/usr/bin/perl

use strict;
use warnings;

use Benchmark;

timethese -10, {
    C    =>  'my $sum; for (my $i = 0; $i < 1000000; $i += 2) {$sum +=
+ $i}',
    AWK  =>  'my $sum; for my $i (map {$_ * 2} 0 .. 1000000 / 2) {$sum
+ += $i}'
};

__END__
Benchmark: running C, AWK for at least 10 CPU seconds...
     C: 10 wallclock secs (10.66 usr +  0.00 sys = 10.66 CPU) @  1.41/
+s (n=15)
   AWK: 10 wallclock secs (10.08 usr +  0.00 sys = 10.08 CPU) @  0.69/
+s (n=7)

Abigail

[demerphq]

This is predicated on @numbers being sorted, a precondition we werent provided with, furthermore if the list is empty it returns an incorrect result. Ie 0.

Sorry, I misread the shift() as somehow being pop(). (/note to self, get glasses checked, and reduce the caffiene intake :-) But its still does return a 0 if there are no elements...

--- demerphq
my friends call me, usually because I'm late....