package expl8m;  # expl8m.m         package for expl8.pl

use strict;
use Exporter qw(import);

our $VERSION    = 1.00;
our @ISA        = qw(Exporter);
our @EXPORT_OK  = qw(matadd matsub); # see matrix.pm for many subroutines

sub matadd {
    my ($mat1, $mat2, $sum) = @_; # parameters
    my $r1 = @$mat1;
    my $c1 = @{$mat1->[0]};
    my $r2 = @$mat2;
    my $c2 = @{$mat2->[0]};
    print "in matadd r1=$r1, c1=$c1, r2=$r2, c2=$c2 \n";

    for (my $i = 0; $i < $r1; $i++) {
        for (my $j = 0; $j < $c1; $j++) {
           $sum->[$i][$j] = $mat1->[$i][$j] + $mat2->[$i][$j];
        }
    }
} # end matadd

sub matsub {
    my ($mat1, $mat2, $sum) = @_; # parameters
    my $r1 = @$mat1;
    my $c1 = @{$mat1->[0]};
    my $r2 = @$mat2;
    my $c2 = @{$mat2->[0]};
    print "in matsub r1=$r1, c1=$c1, r2=$r2, c2=$c2 \n";

    for (my $i = 0; $i < $r1; $i++) {
        for (my $j = 0; $j < $c1; $j++) {
           $sum->[$i][$j] = $mat1->[$i][$j] - $mat2->[$i][$j];
        }
    }
} # end matsub

1;