refactor: clamp return value to expected range

Signed-off-by: Athan <kgryte@gmail.com>

Author: kgryte

lib/node_modules/@stdlib/stats/strided/dpcorrwd/lib/ndarray.js

@@ -21,6 +21,7 @@
 // MODULES //
 
 var sqrt = require( '@stdlib/math/base/special/sqrt' );
+var clamp = require( '@stdlib/math/base/special/clamp' );
 
 
 // MAIN //
@@ -162,6 +163,7 @@ function dpcorrwd( N, x, strideX, offsetX, y, strideY, offsetY ) {
 	var sx;
 	var sy;
 	var C;
+	var r;
 	var i;
 
 	if ( N <= 0 ) {
@@ -194,7 +196,8 @@ function dpcorrwd( N, x, strideX, offsetX, y, strideY, offsetY ) {
 	}
 	sx = sqrt( M2x/N );
 	sy = sqrt( M2y/N );
-	return ( C/N ) / ( sx*sy ); // Note: why all the dividing by `N`? To avoid overflow.
+	r = ( C/N ) / ( sx*sy ); // Why all the dividing by `N`? To avoid overflow.
+	return clamp( r, -1.0, 1.0 ); // Guard against floating-point errors resulting in |r| > 1
 }