sub int_gen_curve
{
        my ($self, $x, $mean, $sdev ) = @_;
	my $pi = 3.14159265358979323844;
        return 1 / ( sqrt( 2 * $pi * $sdev * $sdev ))
                * exp( -($x-$mean)*($x-$mean) / ( 2 * $sdev * $sdev ));
}