3D arrays, again

stu96art has asked for the wisdom of the Perl Monks concerning the following question:

I want to thank everyone for helping me, but I am still having trouble. I am trying to get data from a file, like the one below. The 88888 marker means the end of a block. What I am trying to do is have a list of blocks which contain a list of vertices, which contains four elements. I am a little confused on how to read the vertices into the array when I don't know how many there are until I read the file. I apologize if I am repeating myself, but I am still confused. I am using a two dimensional array now and below the data is the code I use to get that. Could I do something like $Block[0] = @datavertex[0];? SO that I can have $Block[0][0][1]


1
786.582394
1480.624270
2
877.141985
1284.635536
3
779.147607
1239.355735
4
688.588015
1435.344469
5
786.582394
1480.624270
88888
6
664.833374
241.139500
7
661.222659
245.226628
[download]

VERTEX: while ($line1 = <FHV>) {
    if ($line1 == $ek) {
#        print "BLOCK END\n";
        $line1 = <FHV>;
        if ($line1 = eof) {
            last VERTEX;
        }
    }
    my @vertex = (
               scalar($line1),
               scalar(<FHV>),
               scalar(<FHV>),
               scalar(0) );
    $vertexcount = $vertexcount + 1;
    chomp @vertex;
    push @datavertex, \ @vertex;
}
[download]

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Re: 3D arrays, again by cfreak (Chaplain) on Feb 07, 2003 at 23:07 UTC
I'm confused by your 88888 to read blocks (maybe because I'm not seeing it in your data), as far as creating multi-diminsional arrays, they aren't really supported in Perl but you can duplicate the functionality using references. Could I do something like `$Block[0] = @datavertex[0];`? SO that I can have `$Block[0][0][1]` Not really, use references. Something like this would do it: `my @array = qw(oranges bannanas apples kiwi); my @array2 = (); $array2[0] = \@array; my @array3 = (); $array3[0] = \@array2; # ad nausium ...` [download] So now you could dereference and get 'oranges' from the third array `my $fruit = $array3[0]->[0]->[0];` Also if you're using a loop to set up that same structure you can do it in one statement, like this (assuming you already defined array3: `$array3[0] = [['oranges','bannanas','apples','kiwi']]; # and multiple ones like this $array3[0] = [['oranges','bannanas'],['apples','kiwi']];` [download] I hope that gives you a better idea, I'm not understanding exactly what it is your doing, maybe if you provide some of the data I could give you a better example. Chris Lobster Aliens Are attacking the world!	[reply] [d/l] [select]
Re: 3D arrays, again by BrowserUk (Patriarch) on Feb 07, 2003 at 23:55 UTC
I think this gets close to what your looking for #! perl -slw use strict; my (@blocks, $datavertex); # Build the structure while(my $in = <DATA>) { if ( $in =~ /^88888/ ) { push @blocks, $datavertex; $datavertex = []; next; } my @vertex = ($in, scalar <DATA>, scalar <DATA>, 0); chomp @vertex; push @{$datavertex}, \@vertex; } push @blocks, $datavertex if @$datavertex; #! push the last block # Accessing it for my $block (0..$#blocks) { for my $dv ( 0 .. $#{$blocks[$block]} ) { for my $vertex ( 0 .. $#{$blocks[$block][$dv]} ) { print"[$block][$dv][$vertex] =>", $blocks[$block][$dv][$ve +rtex]; } print ''; } } __DATA__ 1 786.582394 1480.624270 2 877.141985 1284.635536 3 779.147607 1239.355735 4 688.588015 1435.344469 5 786.582394 1480.624270 88888 6 664.833374 241.139500 7 661.222659 245.226628 [download] The output Read more... (1520 Bytes) Examine what is said, not who speaks. The 7th Rule of perl club is -- pearl clubs are easily damaged. Use a diamond club instead.	[reply] [d/l] [select]
Re: 3D arrays, again by justinNEE (Monk) on Feb 07, 2003 at 23:52 UTC
stu, is this what you want? `$array2[0][0]` is 'oranges'. `my @array = qw(oranges bannanas apples kiwi); my @array2 = (); $array2[0] = \@array; # ad nausium ... print $array2[0][0];` [download] update forgot to address the other part of your question. "I am a little confused on how to read the vertices into the array when I don't know how many there are until I read the file." You are doing this by saying, while there is another line of data to be read, ... `while ($line1 = <FHV>) {` [download]	[reply] [d/l] [select]