feat: add math/base/special/gammasgnf

lib/node_modules/@stdlib/math/base/special/gammasgnf/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2025 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.
+
+-->
+
+# gammasgnf
+
+> Sign of the [gamma function][@stdlib/math/base/special/gamma] for a single-precision floating-point number.
+
+<section class="intro">
+
+The sign of the [gamma-function][@stdlib/math/base/special/gamma] is defined as
+
+<!-- <equation class="equation" label="eq:gamma_sign_function" align="center" raw="\operatorname{gammasgn} ( x ) = \begin{cases} 1 & \textrm{if}\ \Gamma > 0 \\ -1 & \textrm{if}\ \Gamma < 0 \\ 0 & \textrm{otherwise}\ \end{cases}" alt="Sign of the gamma function"> -->
+
+```math
+\mathop{\mathrm{gammasgn}} ( x ) = \begin{cases} 1 & \textrm{if}\ \Gamma > 0 \\ -1 & \textrm{if}\ \Gamma < 0 \\ 0 & \textrm{otherwise}\ \end{cases}
+```
+
+<!-- </equation> -->
+
+The [gamma function][@stdlib/math/base/special/gamma] can be computed as the product of `gammasgn(x)` and `exp(gammaln(x))`.
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var gammasgnf = require( '@stdlib/math/base/special/gammasgnf' );
+```
+
+#### gammasgnf( x )
+
+Computes the sign of the [gamma function][@stdlib/math/base/special/gamma] for a single-precision floating-point number.
+
+```javascript
+var v = gammasgnf( 1.0 );
+// returns 1.0
+
+v = gammasgnf( -2.5 );
+// returns -1.0
+
+v = gammasgnf( 0.0 );
+// returns 0.0
+
+v = gammasgnf( NaN );
+// returns NaN
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   The [gamma function][@stdlib/math/base/special/gamma] is not defined for negative integer values (i.e., `gamma(x) === NaN` when `x` is a negative integer). The [natural logarithm of the gamma function][@stdlib/math/base/special/gammaln] is defined for negative integer values (i.e., `gammaln(x) === Infinity` when `x` is a negative integer). Accordingly, in order for the equality `gamma(x) === gammasgn(x) * exp(gammaln(x))` to hold (i.e., return `NaN`), `gammasgn` needs to either return `NaN` or `0`. By convention, this function returns `0`.
+
+</section>
+
+<!-- /. notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var logEachMap = require( '@stdlib/console/log-each-map' );
+var uniform = require( '@stdlib/random/array/uniform' );
+var gammasgnf = require( '@stdlib/math/base/special/gammasgnf' );
+
+var x = uniform( 100, -10.0, 10.0, {
+    'dtype': 'float32'
+});
+
+logEachMap( 'x: %0.4f, f(x): %0.4f', x, gammasgnf );
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- C interface documentation. -->
+
+* * *
+
+<section class="c">
+
+## C APIs
+
+<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<!-- C usage documentation. -->
+
+<section class="usage">
+
+### Usage
+
+```c
+#include "stdlib/math/base/special/gammasgnf.h"
+```
+
+#### stdlib_base_gammasgnf( x )
+
+Computes the sign of the [gamma function][@stdlib/math/base/special/gamma] for a single-precision floating-point number.
+
+```c
+float out = stdlib_base_gammasgnf( 1.0f );
+// returns 1.0f
+
+out = stdlib_base_gammasgnf( -2.5f );
+// returns -1.0f
+```
+
+The function accepts the following arguments:
+
+-   **x**: `[in] float` input value.
+
+```c
+float stdlib_base_gammasgnf( const float x );
+```
+
+</section>
+
+<!-- /.usage -->
+
+<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="notes">
+
+</section>
+
+<!-- /.notes -->
+
+<!-- C API usage examples. -->
+
+<section class="examples">
+
+### Examples
+
+```c
+#include "stdlib/math/base/special/gammasgnf.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+int main( void ) {
+    float x;
+    float v;
+    int i;
+
+    for ( i = 0; i < 100; i++ ) {
+        x = ( (float)rand() / (float)RAND_MAX ) * 100.0f;
+        v = stdlib_base_gammasgnf( x );
+        printf( "gammasgnf(%f) = %f\n", x, v );
+    }
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+</section>
+
+<!-- /.c -->
+
+<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
+
+<section class="related">
+
+</section>
+
+<!-- /.related -->
+
+<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="links">
+
+[@stdlib/math/base/special/gamma]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/math/base/special/gamma
+
+[@stdlib/math/base/special/gammaln]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/math/base/special/gammaln
+
+<!-- <related-links> -->
+
+<!-- </related-links> -->
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/math/base/special/gammasgnf/benchmark/benchmark.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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 bench = require( '@stdlib/bench' );
+var uniform = require( '@stdlib/random/array/uniform' );
+var isnanf = require( '@stdlib/math/base/assert/is-nanf' );
+var pkg = require( './../package.json' ).name;
+var gammasgnf = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+	var x;
+	var y;
+	var i;
+
+	x = uniform( 100, -10.0, 10.0, {
+		'dtype': 'float32'
+	});
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		y = gammasgnf( x[ i%x.length ] );
+		if ( isnanf( y ) ) {
+			b.fail( 'should not return NaN' );
+		}
+	}
+	b.toc();
+	if ( isnanf( y ) ) {
+		b.fail( 'should not return NaN' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});

lib/node_modules/@stdlib/math/base/special/gammasgnf/benchmark/benchmark.native.js

@@ -0,0 +1,63 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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 bench = require( '@stdlib/bench' );
+var uniform = require( '@stdlib/random/array/uniform' );
+var isnanf = require( '@stdlib/math/base/assert/is-nanf' );
+var tryRequire = require( '@stdlib/utils/try-require' );
+var pkg = require( './../package.json' ).name;
+
+
+// VARIABLES //
+
+var gammasgnf = tryRequire( resolve( __dirname, './../lib/native.js' ) );
+var opts = {
+	'skip': ( gammasgnf instanceof Error )
+};
+
+
+// MAIN //
+
+bench( pkg+'::native', opts, function benchmark( b ) {
+	var x;
+	var y;
+	var i;
+
+	x = uniform( 100, -10.0, 10.0, {
+		'dtype': 'float32'
+	});
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		y = gammasgnf( x[ i%x.length ] );
+		if ( isnanf( y ) ) {
+			b.fail( 'should not return NaN' );
+		}
+	}
+	b.toc();
+	if ( isnanf( y ) ) {
+		b.fail( 'should not return NaN' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});