fix: update sind to follow the IEEE 754-2019 standard

PR-URL: #6592
Reviewed-by: Athan Reines <[email protected]>
Signed-off-by: Karan Anand <[email protected]>

Author: anandkaranubc

lib/node_modules/@stdlib/math/base/special/sind/lib/main.js

@@ -69,7 +69,7 @@ function sind( x ) {
 	arx = abs( rx );
 
 	if ( rx === 0.0 ) {
-		return 0.0;
+		return rx;
 	}
 	if ( arx < 45.0 ) {
 		return kernelSin( deg2rad( rx ), 0.0 );

lib/node_modules/@stdlib/math/base/special/sind/src/main.c

@@ -48,7 +48,7 @@ double stdlib_base_sind( const double x ) {
 	arx = stdlib_base_abs( rx );
 
 	if ( rx == 0.0 ) {
-		return 0.0;
+		return rx;
 	}
 	if ( arx < 45.0 ) {
 		return stdlib_base_kernel_sin( stdlib_base_deg2rad( rx ), 0.0 );

lib/node_modules/@stdlib/math/base/special/sind/test/test.js

@@ -26,6 +26,8 @@ var abs = require( '@stdlib/math/base/special/abs' );
 var EPS = require( '@stdlib/constants/float64/eps' );
 var PINF = require( '@stdlib/constants/float64/pinf' );
 var NINF = require( '@stdlib/constants/float64/ninf' );
+var isNegativeZero = require( '@stdlib/assert/is-negative-zero' );
+var isPositiveZero = require( '@stdlib/assert/is-positive-zero' );
 var sind = require( './../lib' );
 
 
@@ -109,15 +111,34 @@ tape( 'if provided `-infinity`, the function returns `NaN`', function test( t )
 	t.end();
 });
 
-tape( 'if provided a multiple of `180.0`, the function returns `0.0`', function test( t ) {
+tape( 'if provided a positive multiple of `180.0`, the function returns `0.0`', function test( t ) {
 	var v = sind( 180.0 );
-	t.strictEqual( v, 0.0, 'returns expected value' );
-
-	v = sind( -180.0 );
-	t.strictEqual( v, 0.0, 'returns expected value' );
+	t.strictEqual( isPositiveZero( v ), true, 'returns expected value' );
 
 	v = sind( 360.0 );
-	t.strictEqual( v, 0.0, 'returns expected value' );
+	t.strictEqual( isPositiveZero( v ), true, 'returns expected value' );
+
+	t.end();
+});
+
+tape( 'if provided a negative multiple of `180.0`, the function returns `-0.0`', function test( t ) {
+	var v = sind( -180.0 );
+	t.strictEqual( isNegativeZero( v ), true, 'returns expected value' );
+
+	v = sind( -360.0 );
+	t.strictEqual( isNegativeZero( v ), true, 'returns expected value' );
+
+	t.end();
+});
+
+tape( 'the function returns `-0` if provided `-0`', function test( t ) {
+	var v = sind( -0.0 );
+	t.strictEqual( isNegativeZero( v ), true, 'returns expected value' );
+	t.end();
+});
 
+tape( 'the function returns `+0` if provided `+0`', function test( t ) {
+	var v = sind( 0.0 );
+	t.strictEqual( isPositiveZero( v ), true, 'returns expected value' );
 	t.end();
 });

lib/node_modules/@stdlib/math/base/special/sind/test/test.native.js

@@ -27,6 +27,8 @@ var abs = require( '@stdlib/math/base/special/abs' );
 var EPS = require( '@stdlib/constants/float64/eps' );
 var PINF = require( '@stdlib/constants/float64/pinf' );
 var NINF = require( '@stdlib/constants/float64/ninf' );
+var isNegativeZero = require( '@stdlib/assert/is-negative-zero' );
+var isPositiveZero = require( '@stdlib/assert/is-positive-zero' );
 var tryRequire = require( '@stdlib/utils/try-require' );
 
 
@@ -118,15 +120,34 @@ tape( 'if provided `-infinity`, the function returns `NaN`', opts, function test
 	t.end();
 });
 
-tape( 'if provided a multiple of `180.0`, the function returns `0.0`', opts, function test( t ) {
+tape( 'if provided a positive multiple of `180.0`, the function returns `0.0`', opts, function test( t ) {
 	var v = sind( 180.0 );
-	t.strictEqual( v, 0.0, 'returns expected value' );
-
-	v = sind( -180.0 );
-	t.strictEqual( v, 0.0, 'returns expected value' );
+	t.strictEqual( isPositiveZero( v ), true, 'returns expected value' );
 
 	v = sind( 360.0 );
-	t.strictEqual( v, 0.0, 'returns expected value' );
+	t.strictEqual( isPositiveZero( v ), true, 'returns expected value' );
+
+	t.end();
+});
+
+tape( 'if provided a negative multiple of `180.0`, the function returns `0.0`', opts, function test( t ) {
+	var v = sind( -180.0 );
+	t.strictEqual( isNegativeZero( v ), true, 'returns expected value' );
+
+	v = sind( -360.0 );
+	t.strictEqual( isNegativeZero( v ), true, 'returns expected value' );
+
+	t.end();
+});
+
+tape( 'the function returns `-0` if provided `-0`', opts, function test( t ) {
+	var v = sind( -0.0 );
+	t.strictEqual( isNegativeZero( v ), true, 'returns expected value' );
+	t.end();
+});
 
+tape( 'the function returns `+0` if provided `+0`', opts, function test( t ) {
+	var v = sind( 0.0 );
+	t.strictEqual( isPositiveZero( v ), true, 'returns expected value' );
 	t.end();
 });