npm package: @stdlib/math-base-special-sec
Description: Compute the secant of a number.
Author: The Stdlib Authors
Latest version: 0.1.1

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<details>
  <summary>
    About stdlib...
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  <p>We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.</p>
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# Secant

[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url] <!-- [![dependencies][dependencies-image]][dependencies-url] -->

> Evaluate the [secant][trigonometric-functions] of a number.

<section class="intro">

</section>

<section class="installation">

## Installation

```bash
npm install @stdlib/math-base-special-sec
```

</section>

<section class="usage">

## Usage

```javascript
var sec = require( '@stdlib/math-base-special-sec' );
```

#### sec( x )

Evaluates the [secant][trigonometric-functions] of `x` (in radians).

```javascript
var v = sec( 0.0 );
// returns 1.0

v = sec( 3.141592653589793/2.0 );
// returns 16331239353195370.0

v = sec( -3.141592653589793/3.0 );
// returns ~1.9999999999999996

v = sec( 3.141592653589793/3.0 );
// returns ~1.9999999999999996

v = sec( NaN );
// returns NaN
```

</section>

<!-- /.usage -->

<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 TWO_PI = require( '@stdlib/constants-float64-two-pi' );
var sec = require( '@stdlib/math-base-special-sec' );

var opts = {
    'dtype': 'float64'
};
var x = uniform( 100, -TWO_PI, TWO_PI, opts );

logEachMap( 'sec(%0.4f) = %0.4f', x, sec );
```

</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/sec.h"
```

#### stdlib_base_sec( x )

Evaluates the [secant][trigonometric-functions] of `x` (in radians).

```c
double out = stdlib_base_sec( 0.0 );
// returns 1.0

out = stdlib_base_cos( 3.141592653589793 / 2.0 );
// returns 6.123233995736766e-17
```

The function accepts the following arguments:

-   **x**: `[in] double` input value.

```c
double stdlib_base_sec( const double 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/sec.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { 0.523, 0.785, 1.047, 3.14 };

    double y;
    int i;
    for ( i = 0; i < 4; i++ ) {
        y = stdlib_base_sec( x[ i ] );
        printf( "sec(%lf) = %lf\n", x[ i ], y );
    }
}
```

</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 -->

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<section class="main-repo" >

* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

#### Community

[![Chat][chat-image]][chat-url]

---

## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

</section>

<!-- /.stdlib -->

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<section class="links">

[npm-image]: http://img.shields.io/npm/v/@stdlib/math-base-special-sec.svg
[npm-url]: https://npmjs.org/package/@stdlib/math-base-special-sec

[test-image]: https://github.com/stdlib-js/math-base-special-sec/actions/workflows/test.yml/badge.svg?branch=v0.1.1
[test-url]: https://github.com/stdlib-js/math-base-special-sec/actions/workflows/test.yml?query=branch:v0.1.1

[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/math-base-special-sec/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/math-base-special-sec?branch=main

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[stdlib]: https://github.com/stdlib-js/stdlib

[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors

[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules

[deno-url]: https://github.com/stdlib-js/math-base-special-sec/tree/deno
[deno-readme]: https://github.com/stdlib-js/math-base-special-sec/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/math-base-special-sec/tree/umd
[umd-readme]: https://github.com/stdlib-js/math-base-special-sec/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/math-base-special-sec/tree/esm
[esm-readme]: https://github.com/stdlib-js/math-base-special-sec/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/math-base-special-sec/blob/main/branches.md

[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/math-base-special-sec/main/LICENSE

[trigonometric-functions]: https://en.wikipedia.org/wiki/Trigonometric_functions

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</section>

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