180 lines
3.0 KiB
Markdown
180 lines
3.0 KiB
Markdown
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<!--
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@license Apache-2.0
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Copyright (c) 2018 The Stdlib Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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-->
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# abs2
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> Compute the squared [absolute value][absolute-value] of a double-precision floating-point number.
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<section class="intro">
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</section>
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<!-- /.intro -->
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<section class="usage">
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## Usage
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```javascript
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var abs2 = require( '@stdlib/math/base/special/abs2' );
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```
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#### abs2( x )
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Computes the squared [absolute value][absolute-value] of a double-precision floating-point number.
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```javascript
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var v = abs2( -1.0 );
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// returns 1.0
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v = abs2( 2.0 );
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// returns 4.0
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v = abs2( 0.0 );
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// returns 0.0
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v = abs2( -0.0 );
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// returns 0.0
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v = abs2( NaN );
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// returns NaN
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```
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</section>
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<!-- /.usage -->
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<section class="examples">
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## Examples
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<!-- eslint no-undef: "error" -->
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```javascript
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var randu = require( '@stdlib/random/base/randu' );
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var round = require( '@stdlib/math/base/special/round' );
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var abs2 = require( '@stdlib/math/base/special/abs2' );
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var x;
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var i;
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for ( i = 0; i < 100; i++ ) {
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x = round( randu() * 100.0 ) - 50.0;
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console.log( 'abs2(%d) = %d', x, abs2( x ) );
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}
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```
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</section>
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<!-- /.examples -->
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<!-- C interface documentation. -->
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* * *
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<section class="c">
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## C APIs
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<!-- Section to include introductory text. Make sure to keep an empty line after the intro `section` element and another before the `/section` close. -->
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<section class="intro">
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</section>
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<!-- /.intro -->
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<!-- C usage documentation. -->
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<section class="usage">
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### Usage
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```c
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#include "stdlib/math/base/special/abs2.h"
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```
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#### stdlib_base_abs2( x )
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Computes the squared absolute value of a double-precision floating-point number.
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```c
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double y = stdlib_base_abs2( -5.0 );
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// returns 25.0
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```
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The function accepts the following arguments:
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- **x**: `[in] double` input value.
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```c
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double stdlib_base_abs2( const double x );
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```
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</section>
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<!-- /.usage -->
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<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
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<section class="notes">
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</section>
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<!-- /.notes -->
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<!-- C API usage examples. -->
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<section class="examples">
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### Examples
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```c
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#include "stdlib/math/base/special/abs2.h"
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#include <stdio.h>
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int main() {
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double x[] = { 3.14, -3.14, 0.0, 0.0/0.0 };
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double y;
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int i;
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for ( i = 0; i < 4; i++ ) {
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y = stdlib_base_abs2( x[ i ] );
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printf( "abs2(%lf) = %lf\n", x[ i ], y );
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}
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}
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```
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</section>
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<!-- /.examples -->
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</section>
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<!-- /.c -->
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<section class="links">
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[absolute-value]: https://en.wikipedia.org/wiki/Absolute_value
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</section>
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<!-- /.links -->
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