feat: c bug fix and tests added

Author: aayush0325

lib/node_modules/@stdlib/stats/base/dists/arcsine/kurtosis/src/main.c

@@ -38,5 +38,5 @@ double stdlib_base_dists_arcsine_kurtosis( const double a, const double b ) {
 	) {
 		return 0.0 / 0.0; // NaN
 	}
-	return 1.5;
+	return -1.5;
 }

lib/node_modules/@stdlib/stats/base/dists/arcsine/kurtosis/test/test.native.js

@@ -0,0 +1,89 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2018 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var resolve = require( 'path' ).resolve;
+var tape = require( 'tape' );
+var tryRequire = require( '@stdlib/utils/try-require' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var randu = require( '@stdlib/random/base/randu' );
+var PINF = require( '@stdlib/constants/float64/pinf' );
+var NINF = require( '@stdlib/constants/float64/ninf' );
+
+
+// VARIABLES //
+
+var kurtosis = tryRequire( resolve( __dirname, './../lib/native.js' ) );
+var opts = {
+	'skip': ( kurtosis instanceof Error )
+};
+
+
+// TESTS //
+
+tape( 'main export is a function', opts, function test( t ) {
+	t.ok( true, __filename );
+	t.strictEqual( typeof kurtosis, 'function', 'main export is a function' );
+	t.end();
+});
+
+tape( 'if provided `NaN` for any parameter, the function returns `NaN`', opts, function test( t ) {
+	var v = kurtosis( NaN, 0.5 );
+	t.equal( isnan( v ), true, 'returns NaN' );
+
+	v = kurtosis( 10.0, NaN );
+	t.equal( isnan( v ), true, 'returns NaN' );
+
+	t.end();
+});
+
+tape( 'if provided `a >= b`, the function returns `NaN`', opts, function test( t ) {
+	var y;
+
+	y = kurtosis( 3.0, 2.0 );
+	t.equal( isnan( y ), true, 'returns NaN' );
+
+	y = kurtosis( 2.0, 2.0 );
+	t.equal( isnan( y ), true, 'returns NaN' );
+
+	y = kurtosis( NINF, NINF );
+	t.equal( isnan( y ), true, 'returns NaN' );
+
+	y = kurtosis( PINF, NINF );
+	t.equal( isnan( y ), true, 'returns NaN' );
+
+	t.end();
+});
+
+tape( 'the function returns `-3/2` as the excess kurtosis of an arcsine distribution ', opts, function test( t ) {
+	var a;
+	var b;
+	var i;
+	var v;
+
+	for ( i = 0; i < 10; i++ ) {
+		a = ( randu() *10.0 );
+		b = ( randu()*10.0 ) + a;
+		v = kurtosis( a, b );
+		t.equal( v, -3/2, 'returns -3/2' );
+	}
+	t.end();
+});