#!/usr/bin/perl -w

# ----------------------------------------------------------------
# John Kerl
# kerl.john.r@gmail.com
# 2005-01-11
#
# This is a matrix multiply.  Example:
#
# bash$ cat a.txt
# -2  1  0  0
#  1 -2  1  0
#  0  1 -2  1
#  0  0  1 -2
# bash$ cat b.txt
#  1  2  3  4  5
#  5  6  7  8  9
#  1  3  5  7  9
#  0  2  4  6  8
# bash$ pmatmul a.txt b.txt
#  3.0000  2.0000  1.0000  0.0000 -1.0000
# -8.0000 -7.0000 -6.0000 -5.0000 -4.0000
#  3.0000  2.0000  1.0000  0.0000 -1.0000
#  1.0000 -1.0000 -3.0000 -5.0000 -7.0000
# ----------------------------------------------------------------

# Setup information:
# (1) Obtain my PMATLIB.pm;
# (2) Put PMATLIB.pm somewhere, e.g. the $HOME/bin directory;
# (3) Include that directory in the PERLLIB environment variable.
#     For bash, if PERLLIB exists:         export PERLLIB=$HOME/bin
#     For bash, if PERLLIB does not exist: export PERLLIB=$PERLLIB:$HOME/bin
#     For csh, if PERLLIB exists:          setenv PERLLIB $HOME/bin
#     For csh, if PERLLIB does not exist:  setenv PERLLIB ${PERLLIB}:$HOME/bin
use PMATLIB;

while (@ARGV) {
	last unless $ARGV[0] =~ m/^-/;

	if (pmatlib_opt(\@ARGV)) {
		;
	}

	elsif ($ARGV[0] eq "-t") {
		shift @ARGV;
		@transpose_indices[shift @ARGV] = 1;
	}

	else {
		usage();
	}
}

if (@ARGV < 1) {
	usage();
}
else {

	$count = 1;
	@A = (); $anr = 0; $anc = 0; 
	read_matrix(\@A, \$anr, \$anc, $ARGV[0]);
	shift @ARGV;
	transpose_in_place(\@A, \$anr, \$anc) if ($transpose_indices[$count++]);

	while (@ARGV) {
		@B = (); $bnr = 0; $bnc = 0; 
		read_matrix(\@B, \$bnr, \$bnc, $ARGV[0]);
		shift @ARGV;
		transpose_in_place(\@B, \$bnr, \$bnc) if ($transpose_indices[$count++]);
		matmul(\@A, $anr, $anc, \@B, $bnr, $bnc, \@A, \$anr, \$anc);
	}
	transpose_in_place(\@A, \$anr, \$anc) if ($transpose_indices[$count++]);
	print_matrix(\@A, $anr, $anc);

}

# ----------------------------------------------------------------
sub usage
{
	die
		"Usage: $0 [options] {input 1 file name} {input 2 file name}\n" .
		"Options:\n" .
		pmatlib_options_string() .
		"  -t 1: transpose input 1 before multiplying.\n" .
		"  -t 2: transpose input 2 before multiplying.\n" .
		"  -t 3: transpose output  after  multiplying.\n";
}