This program is to prompt the user for a temperature and use the input to compute potential temperature at each pressure level from 500 to 1000 in increments of 100. I used: 
my (@thetas, @press);
my ($i);

use strict;
use warnings;

my $outfilename = "pot_temp.txt";# define an output filename
open(TFILE,">$outfilename");

print "What is the temperature (K)? \n";
my $T = <STDIN>;
chomp ($T);

for ($i=500, $i=900 , $i += 100) 
    {
    my $theta = $T*((1013/$i)**(287/1004));
    push (@press, $i);
    push (@thetas,$theta);
    }
    
print TFILE "A T of $T results in thetas of @thetas at the pressure le
+vels @press \n";

[download]
The file gets written fine, but the results are bogus so the problem is in the loop. Specifically, I get three identical values for $theta and $i, and I should get 5 different values.

Thanks to those that offered advice to my last "Improve my Coding" post. I tried to implement some suggestions.

In reply to For loop trouble by cheech

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