feat: add C implementation math/base/special/logitf

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

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2022 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.
+
+-->
+
+# logitf
+
+> Compute the [logit][logit] function. of single-precision floating-point number.
+
+<section class="intro">
+
+The [logit][logit] function is defined as the logarithm of the odds `p / (1-p)`; i.e.,
+
+<!-- <equation class="equation" label="eq:logit_function" align="center" raw="\operatorname{logit}(p)=\log \left({\frac {p}{1-p}}\right)" alt="Logit function."> -->
+
+```math
+\mathop{\mathrm{logit}}(p)=\log \left({\frac {p}{1-p}}\right)
+```
+
+<!-- <div class="equation" align="center" data-raw-text="\operatorname{logit}(p)=\log \left({\frac {p}{1-p}}\right)" data-equation="eq:logit_function">
+    <img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@bb29798906e119fcb2af99e94b60407a270c9b32/lib/node_modules/@stdlib/math/base/special/logit/docs/img/equation_logit_function.svg" alt="Logit function.">
+    <br>
+</div> -->
+
+<!-- </equation> -->
+
+The [logit][logit] function is the inverse of the [standard logistic][standard-logistic] function, sometimes also called the sigmoid function.
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var logitf = require( '@stdlib/math/base/special/logitf' );
+```
+
+#### logitf( p )
+
+Computes the [logit][logit] function of single-precision floating-point number.
+
+```javascript
+var v = logitf( 0.2 );
+// returns ~-1.386
+
+v = logitf( 0.9 );
+// returns ~2.197
+```
+
+If `p < 0` or `p > 1`, the function returns `NaN`.
+
+```javascript
+var v = logitf( 1.3 );
+// returns NaN
+
+v = logitf( -0.2 );
+// returns NaN
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var randu = require( '@stdlib/random/base/randu' );
+var logitf = require( '@stdlib/math/base/special/logitf' );
+
+var p;
+var i;
+
+for ( i = 0; i < 100; i++ ) {
+    p = randu();
+    console.log( 'logitf(%d) = %d', p, logitf( p ) );
+}
+```
+
+</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/logitf.h"
+```
+
+#### stdlib_base_logitf( p )
+
+Computes the [logit][logit] function of single-precision floating-point number.
+
+```c
+float out = stdlib_base_logitf( 0.2 );
+// returns ~-1.386
+
+out = stdlib_base_logitf( 0.9 );
+// returns ~2.197
+```
+
+The function accepts the following arguments:
+
+-   **p**: `[in] float` input value.
+
+```c
+float stdlib_base_logitf( const float p );
+```
+
+</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/logitf.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;
+        v = stdlib_base_logitf( x );
+        printf( "logitf(%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">
+
+[logit]: https://en.wikipedia.org/wiki/Logit
+
+[standard-logistic]: https://en.wikipedia.org/wiki/Logistic_function
+
+</section>
+
+<!-- /.links -->

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

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+/**
+* @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 bench = require( '@stdlib/bench' );
+var randu = require( '@stdlib/random/base/randu' );
+var isnanf = require( '@stdlib/math/base/assert/is-nanf' );
+var pkg = require( './../package.json' ).name;
+var logitf = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+	var x;
+	var y;
+	var i;
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		x = randu();
+		y = logitf( x );
+		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/logitf/benchmark/benchmark.native.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2022 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 randu = require( '@stdlib/random/base/randu' );
+var isnanf = require( '@stdlib/math/base/assert/is-nanf' );
+var tryRequire = require( '@stdlib/utils/try-require' );
+var pkg = require( './../package.json' ).name;
+
+
+// VARIABLES //
+
+var logitf = tryRequire( resolve( __dirname, './../lib/native.js' ) );
+var opts = {
+	'skip': ( logitf instanceof Error )
+};
+
+
+// MAIN //
+
+bench( pkg+'::native', opts, function benchmark( b ) {
+	var x;
+	var y;
+	var i;
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		x = randu();
+		y = logitf( x );
+		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();
+});