feat: add stats/incr/nanrmse

Author: hrshya

lib/node_modules/@stdlib/stats/incr/nanrmse/test/test.js

@@ -60,14 +60,15 @@ tape( 'the accumulator function incrementally computes the root mean squared err
 	var x;
 	var y;
 	var i;
+	var c;
 
 	data = [
 		[ 2.0, 3.0 ],
 		[ 3.0, -1.0 ],
 		[ 2.0, 5.0 ],
-		[ NaN, 2.0 ],
-		[ 4.0, -4.0 ],
 		[ 1.0, NaN ],
+		[ 4.0, -4.0 ],
+		[ NaN, 2.0 ],
 		[ 3.0, 0.0 ],
 		[ -4.0, 5.0 ]
 	];
@@ -76,14 +77,18 @@ tape( 'the accumulator function incrementally computes the root mean squared err
 	acc = incrnanrmse();
 
 	sum = 0;
+	c = 0;
 	for ( i = 0; i < N; i++ ) {
 		x = data[ i ][ 0 ];
 		y = data[ i ][ 1 ];
-		if ( isnan( d ) === false ) {
+		if ( isnan( x ) === false && isnan( y ) === false ) {
 			r = y - x;
 			sum += r * r;
+			c += 1;
+			expected = sqrt( sum/c );
+		} else {
+			expected = sqrt( sum/c );
 		}
-		expected = sqrt( sum/(i+1) );
 		actual = acc( x, y );
 		if ( actual === expected ) {
 			t.equal( actual, expected, 'returns expected value' );