fix: fix array declaration and data length in test.js

Author: anxhukumar

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

@@ -55,13 +55,13 @@ tape( 'the accumulator function incrementally computes an arithmetic mean', func
 	var d;
 	var N;
 
-	sum = 0;
-	count = 0;
-	N = data.length;
 	data = [ 2.0, 3.0, 2.0, NaN, 4.0, NaN, 3.0, 4.0 ];
+	N = data.length;
+	count = 0;
+	sum = 0;
 
-	expected = Array(N).fill(undefined);
-	actual = Array(N).fill(undefined);
+	expected = []; 
+	actual = [];
 
 	acc = incrnanmean();
 
@@ -71,8 +71,8 @@ tape( 'the accumulator function incrementally computes an arithmetic mean', func
 			sum += d;
 			count += 1;
 		}
-		expected[ i ] = ( count === 0 ) ? null : sum / count;
-		actual[ i ] = acc( d );
+		expected.push( ( count === 0 ) ? null : sum / count );
+		actual.push( acc( d ) );
 	}
 	t.deepEqual( actual, expected, 'returns expected incremental results' );
 	t.end();