#======================================================================

#                    S V B K S B . P L 

#                    doc: Sat Jul 31 22:47:03 1999

#                    dlm: Wed Mar 11 19:29:39 2015

#                    (c) 1999 A.M. Thurnherr

#                    uE-Info: 20 0 NIL 0 0 72 2 2 4 NIL ofnI

#======================================================================

# SVBKSB routine from Numerical Recipes adapted to ANTS

#

#	solves Ax = b for x, given b

#

#	Notes:

#		- A = U W V' as done in [svdcmp.pl]

# HISTORY:

#	Jul 31, 1999: - manually converted from c-source

#	Mar 11, 2015: - fixed syntax errors (code had never been used before)

require "$ANTS/nrutil.pl";

use strict;

sub svbksb($$$$$)

{

	my($uR,$wR,$vR,$bR,$xR) = @_;

	my($jj,$j,$i);									# int

	my($s);										# float

	my(@tmp);									# float[]

	&vector(\@tmp,1,$#{$wR});

	for ($j=1; $j<=$#{$wR}; $j++) {

		$s = 0;

		if ($wR->[$j]) {

			for ($i=1; $i<=$#{$uR}; $i++) {

				$s += $uR->[$i][$j] * $bR->[$i];

			}

			$s /= $wR->[$j];

		}

		$tmp[$j]=$s;

	}

	for ($j=1; $j<=$#{$wR}; $j++) {

		$s = 0;

		for ($jj=1; $jj<=$#{$wR}; $jj++) {

			$s += $vR->[$j][$jj] * $tmp[$jj];

		}

		$xR->[$j] = $s;

	}

}