Re: Sorting large sets of geometric coordinates

A hash isn't appropriate, because nothing is guaranteed to be unique (as far as you've let on). You also ask to sort, and hashes are unordered.

my @unsorted_data;
while (<DATA>) {
   my @fields = /([\d.]+)/g or next;
   push(@unsorted_data, \@fields);
}

my @sorted_data = sort {  $a->[1] <=> $b->[1]
                       || $a->[0] <=> $b->[0] } @unsorted_data;

print("(($_->[0] $_->[1]) ($_->[2] $_->[3]))\n")
   foreach @sorted_data;
[download]

Update: Tested. Fixed the print.

Update: Fixed the error discussed below.

Comment on Re: Sorting large sets of geometric coordinates Select or Download Code

Replies are listed 'Best First'.
Re^2: Sorting large sets of geometric coordinates by thor (Priest) on Apr 20, 2006 at 02:43 UTC
`my @sorted_data = sort { $a->[1] <=> $b->[1] \|\| $a->[0] <=> $a->[0] } @unsorted_data;` [download] Wouldn't the second part of that sort be a no-op? thor `The only easy day was yesterday`	[reply] [d/l]
Re^3: Sorting large sets of geometric coordinates by ikegami (Patriarch) on Apr 20, 2006 at 02:47 UTC
It handles ties in $row_ly. `<=>` returns 0 if the two things it compares are equal. For example, if the compare function were to be called to compare the following two rows, `((5.0 0.4) (48.0 0.5)) ((48.1 0.4) (99.0 0.5))` [download] The first `<=>` would return 0 since `$a->[1] (0.4)` and `$b->[1] (0.4)` are both equal. It would then go on to compare `$a->[0] (5.0)` with `$b->[0] (48.1)` Update: OOPS! Copy and paste error. The code should read: `my @sorted_data = sort { $a->[1] <=> $b->[1] \|\| $a->[0] <=> $b->[0] } @unsorted_data;` [download] Nod to BrowserUk for the head's up.	[reply] [d/l] [select]


Welcome to the Monastery
	PerlMonks