Refactor to support signed zeros and NaNs

kgryte · kgryte · commit 8e3ef7556afe · 2018-05-14T01:13:07.000-07:00
diff --git a/lib/node_modules/@stdlib/stats/incr/mmax/lib/main.js b/lib/node_modules/@stdlib/stats/incr/mmax/lib/main.js
@@ -21,6 +21,8 @@
 // MODULES //
 
 var isPositiveInteger = require( '@stdlib/assert/is-positive-integer' ).isPrimitive;
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var isPositiveZero = require( '@stdlib/math/base/assert/is-positive-zero' );
 var NINF = require( '@stdlib/constants/math/float64-ninf' );
 
 
@@ -78,6 +80,7 @@ function incrmmax( W ) {
 	* // returns 5.0
 	*/
 	function accumulator( x ) {
+		var v;
 		var k;
 		if ( arguments.length === 0 ) {
 			if ( N === 0 ) {
@@ -91,20 +94,35 @@ function incrmmax( W ) {
 		// Case: update initial window...
 		if ( N < W ) {
 			N += 1;
-			if ( x > max ) {
+			if (
+				isnan( x ) ||
+				x > max ||
+				( x === max && isPositiveZero( x ) )
+			) {
 				max = x;
 			}
 		}
-		// Case: incoming value is greater than current maximum value...
-		else if ( x > max ) {
+		// Case: both incoming and outgoing values are NaN...
+		else if ( isnan( x ) && isnan( buf[ i ] ) ) {
+			max = x;
+		}
+		// Case: incoming value is greater than current maximum value OR incoming value is equal to current maximum value which is zero...
+		else if ( x > max || ( x === max && isPositiveZero( x ) ) ) {
 			max = x;
 		}
 		// Case: outgoing value is the current maximum and the new value is less than the maximum, and, thus, we need to find a new maximum among the current values...
-		else if ( buf[ i ] === max && x < max ) {
+		else if ( ( buf[ i ] === max && x < max ) || isnan( buf[ i ] ) ) {
 			max = x;
 			for ( k = 0; k < W; k++ ) {
-				if ( k !== i && buf[ k ] > max ) {
-					max = buf[ k ];
+				if ( k !== i ) {
+					v = buf[ k ];
+					if ( isnan( v ) ) {
+						max = v;
+						break; // no need to continue searching
+					}
+					if ( v > max || ( v === max && isPositiveZero( v ) ) ) {
+						max = v;
+					}
 				}
 			}
 		}
