#======================================================================
#                    . I N T E R P . N N B R 
#                    doc: Wed Nov 22 21:01:09 2000
#                    dlm: Wed Aug  3 11:48:59 2011
#                    (c) 2000 A.M. Thurnherr
#                    uE-Info: 32 0 NIL 0 0 72 8 2 4 NIL ofnI
#======================================================================

# nearest neighbor resampling

# HISTORY:
# 	Nov 22, 2000: - adapted from [.interp.linear]
#	Apr  3, 2004: - added nominal -x
#	Jan 12, 2006: - renamed from [.interp.subsample]
#	Jul 28, 2006: - added xf to ISInit() args
#	Aug 22, 2006: - adapted to work with [match]
#   Aug  5, 2008: - added idr param to IS_init()
#	Aug  3, 2011: - removed -x, which is now handled by [resample]

# see [.interp.linear] for documentation of interface

$IS_opts = "";
$IS_optsUsage = "";

sub IS_usage() {}
sub IS_init($$$$) {}

sub IS_interpolate($$$$$$)
{
	my($bR,$idR,$xf,$xv,$xi,$f) = @_;

	return $bR->[$xi+1][$f]
		if ($bR->[$xi+1][$xf] - $xv < $xv - $bR->[$xi][$xf]);
	return $bR->[$xi][$f];
}

1;