feat: add math/base/special/fast/atanhf

lib/node_modules/@stdlib/math/base/special/fast/atanhf/README.md

@@ -0,0 +1,216 @@
+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2026 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.
+
+-->
+
+# atanhf
+
+> Compute the [hyperbolic arctangent][inverse-hyperbolic] of a single‐precision floating-point number.
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var atanhf = require( '@stdlib/math/base/special/fast/atanhf' );
+```
+
+#### atanhf( x )
+
+Computes the [hyperbolic arctangent][inverse-hyperbolic] of a single‐precision floating-point `number` (in radians).
+
+```javascript
+var v = atanhf( 0.0 );
+// returns 0.0
+
+v = atanhf( -0.0 );
+// returns -0.0
+
+v = atanhf( 0.5 );
+// returns ~0.549
+
+v = atanhf( 0.9 );
+// returns ~1.472
+
+v = atanhf( 1.0 );
+// returns Infinity
+
+v = atanhf( -1.0 );
+// returns -Infinity
+```
+
+The domain of `x` is restricted to `[-1,1]`. If `|x| > 1`, the function returns `NaN`.
+
+```javascript
+var v = atanhf( -3.14 );
+// returns NaN
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   For small `x`, the function will underflow.
+
+    ```javascript
+    var v = atanhf( 1.0e-17 );
+    // returns 0.0
+    // (expected 1.0e-17)
+    ```
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var uniform = require( '@stdlib/random/array/uniform' );
+var logEachMap = require( '@stdlib/console/log-each-map' );
+var atanhf = require( '@stdlib/math/base/special/fast/atanhf' );
+
+var opts = {
+    'dtype': 'float32'
+};
+var x = uniform( 103, -1.0, 1.0, opts );
+
+logEachMap( 'atanhf(%0.4f) = %0.4f', x, atanhf );
+```
+
+</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/fast/atanhf.h"
+```
+
+#### stdlib_base_fast_atanhf( x )
+
+Computes the [hyperbolic arctangent][inverse-hyperbolic] of a single-precision floating-point number (in radians).
+
+```c
+float out = stdlib_base_fast_atanhf( 0.0f );
+// returns 0.0f
+
+out = stdlib_base_fast_atanhf( -0.0f );
+// returns -0.0f
+```
+
+The function accepts the following arguments:
+
+-   **x**: `[in] float` input value.
+
+```c
+float stdlib_base_fast_atanhf( 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/fast/atanhf.h"
+#include <stdio.h>
+
+int main( void ) {
+    const float x[] = { -1.0f, -0.78f, -0.56f, -0.33f, -0.11f, 0.11f, 0.33f, 0.56f, 0.78f, 1.0f };
+
+    float v;
+    int i;
+    for ( i = 0; i < 10; i++ ) {
+        v = stdlib_base_fast_atanhf( x[ i ] );
+        printf( "atanh(%f) = %f\n", x[ i ], 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">
+
+[inverse-hyperbolic]: https://en.wikipedia.org/wiki/Inverse_hyperbolic_function
+
+<!-- <related-links> -->
+
+<!-- </related-links> -->
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/math/base/special/fast/atanhf/benchmark/benchmark.js

@@ -0,0 +1,55 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2026 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 atanhf = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+	var x;
+	var y;
+	var i;
+
+	x = uniform( 100, -1.0, 1.0, {
+		'dtype': 'float32'
+	});
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		y = atanhf( x[ i%x.length ] );
+		if ( isnanf( y ) ) {
+			b.fail( 'should not return NaN' );
+		}
+	}
+	b.toc();
+	if ( isnanf( y ) ) {
+		b.fail( 'should not return NaN' );
+	} else {
+		b.pass( 'benchmark finished' );
+	}
+	b.end();
+});

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

@@ -0,0 +1,65 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2026 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 format = require( '@stdlib/string/format' );
+var tryRequire = require( '@stdlib/utils/try-require' );
+var pkg = require( './../package.json' ).name;
+
+
+// VARIABLES //
+
+var atanhf = tryRequire( resolve( __dirname, './../lib/native.js' ) );
+var opts = {
+	'skip': ( atanhf instanceof Error )
+};
+
+
+// MAIN //
+
+bench( format('%s::native', pkg ), opts, function benchmark( b ) {
+	var x;
+	var y;
+	var i;
+
+	x = uniform( 100, -1.0, 1.0, {
+		'dtype': 'float32'
+	});
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		y = atanhf( x[ i%x.length ] );
+		if ( isnanf( y ) ) {
+			b.fail( 'should not return NaN' );
+		}
+	}
+	b.toc();
+	if ( isnanf( y ) ) {
+		b.fail( 'should not return NaN' );
+	} else {
+		b.pass( 'benchmark finished' );
+	}
+	b.end();
+});