feat: add complex/float64/real

Ref: #2260

lib/node_modules/@stdlib/complex/float64/real/README.md

@@ -0,0 +1,236 @@
+<!--
+
+@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.
+
+-->
+
+# real
+
+> Return the real component of a double-precision complex floating-point number.
+
+<!-- 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 -->
+
+<!-- Package usage documentation. -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var real = require( '@stdlib/complex/float64/real' );
+```
+
+#### real( z )
+
+Returns the **real** component of a double-precision complex floating-point number.
+
+```javascript
+var Complex128 = require( '@stdlib/complex/float64/ctor' );
+
+var z = new Complex128( 5.0, 3.0 );
+var re = real( z );
+// returns 5.0
+```
+
+</section>
+
+<!-- /.usage -->
+
+<!-- Package usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="notes">
+
+</section>
+
+<!-- /.notes -->
+
+<!-- Package usage examples. -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint-disable max-len -->
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var Complex128 = require( '@stdlib/complex/float64/ctor' );
+var discreteUniform = require( '@stdlib/random/base/discrete-uniform' );
+var filledarrayBy = require( '@stdlib/array/filled-by' );
+var real = require( '@stdlib/complex/float64/real' );
+
+function random() {
+    return new Complex128( discreteUniform( -10, 10 ), discreteUniform( -10, 10 ) ); // eslint-disable-line max-len
+}
+
+// Generate an array of random complex numbers:
+var x = filledarrayBy( 100, 'complex128', random );
+// returns <Complex128Array>
+
+// Retrieve the real component of each complex number...
+var z;
+var i;
+for ( i = 0; i < x.length; i++ ) {
+    z = x.get( i );
+    console.log( 'real(%s) = %d', z.toString(), real( z ) );
+}
+```
+
+</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/complex/float64/real.h"
+```
+
+#### stdlib_complex128_real( z )
+
+Returns the real component of a double-precision complex floating-point number.
+
+```c
+#include "stdlib/complex/float64/ctor.h"
+
+stdlib_complex128_t z = stdlib_complex128( 5.0, 2.0 );
+
+// ...
+
+double re = stdlib_complex128_real( z );
+// returns 5.0
+```
+
+The function accepts the following arguments:
+
+-   **z**: `[in] stdlib_complex128_t` double-precision complex floating-point number.
+
+```c
+double stdlib_complex128_real( const stdlib_complex128_t z );
+```
+
+</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/complex/float64/real.h"
+#include "stdlib/complex/float64/ctor.h"
+#include <stdio.h>
+
+int main( void ) {
+    const stdlib_complex128_t x[] = {
+        stdlib_complex128( 5.0, 2.0 ),
+        stdlib_complex128( -2.0, 1.0 ),
+        stdlib_complex128( 0.0, -0.0 ),
+        stdlib_complex128( 0.0/0.0, 0.0/0.0 )
+    };
+
+    int i;
+    for ( i = 0; i < 4; i++ ) {
+        printf( "real(v) = %lf\n", stdlib_complex128_real( x[ i ] ) );
+    }
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+</section>
+
+<!-- /.c -->
+
+<!-- Section to include cited references. If references are included, add a horizontal rule *before* the section. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="references">
+
+</section>
+
+<!-- /.references -->
+
+<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
+
+<section class="related">
+
+* * *
+
+## See Also
+
+-   <span class="package-name">[`@stdlib/complex/float64/imag`][@stdlib/complex/float64/imag]</span><span class="delimiter">: </span><span class="description">return the imaginary component of a double-precision complex floating-point number.</span>
+-   <span class="package-name">[`@stdlib/complex/float64/reim`][@stdlib/complex/float64/reim]</span><span class="delimiter">: </span><span class="description">return the real and imaginary components of a double-precision complex floating-point number.</span>
+
+</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">
+
+<!-- <related-links> -->
+
+[@stdlib/complex/float64/imag]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/complex/float64/imag
+
+[@stdlib/complex/float64/reim]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/complex/float64/reim
+
+<!-- </related-links> -->
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/complex/float64/real/benchmark/benchmark.js

@@ -0,0 +1,57 @@
+/**
+* @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 Complex128 = require( '@stdlib/complex/float64/ctor' );
+var randu = require( '@stdlib/random/base/randu' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pkg = require( './../package.json' ).name;
+var real = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+	var values;
+	var re;
+	var i;
+
+	values = [
+		new Complex128( randu(), randu() ),
+		new Complex128( randu(), randu() ),
+		new Complex128( randu(), randu() )
+	];
+
+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		re = real( values[ i%values.length ] );
+		if ( isnan( re ) ) {
+			b.fail( 'should not return NaN' );
+		}
+	}
+	b.toc();
+	if ( isnan( re ) ) {
+		b.fail( 'should not return NaN' );
+	}
+	b.pass( 'benchmark finished' );
+	b.end();
+});