Re: Weird math...

[Vic Norton]

Here's a short rounding routine that uses sprintf and does produce 
correct results.

#!/usr/bin/perl -w

while (<DATA>) { print round($_,2), "\n" }

sub round {
        my ($number, $places) = @_;
        my $tenpower = 10**$places;
        return (sprintf "%.0f", $number * $tenpower)/$tenpower;
}
__END__
1.655
1.755
Regards,

Vic

At 1:49 PM -0500 10/13/03, Bill Stephenson wrote:
I've got a script that takes numbers similar to those below and then rounds
them and adds them together using code similar to what is below.
    #!/usr/bin/perl -w

    use strict;

    my $item_1 = "1.655";

    my $item_2 = "1.755";

    my $rnd_1 = (sprintf qq~%.2f~, $item_1);

    my $rnd_2 = (sprintf qq~%.2f~, $item_2);

    print "$rnd_1, $rnd_2";

The code above prints this result (system 10.1.5, perl 5.6.0):

    1.66, 1.75

But shouldn't it be:

    1.66, 1.76

or:

    1.65, 1.75

I'm no math wizard, so if someone could please take the time and tell what
I'm missing here I would very much appreciate it!
--

Bill Stephenson
www.PerlHelp.com
1-417-546-5593
--
Vic Norton
vic at norton dot name