128 lines
3.4 KiB
Markdown
128 lines
3.4 KiB
Markdown
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<!--
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@license Apache-2.0
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Copyright (c) 2019 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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# iterprod
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> Compute the product of all [iterated][mdn-iterator-protocol] values.
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<section class="intro">
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The product is defined as
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<!-- <equation class="equation" label="eq:product" align="center" raw="p = \prod_{i=0}^{n-1} x_i" alt="Equation for the product."> -->
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<div class="equation" align="center" data-raw-text="p = \prod_{i=0}^{n-1} x_i" data-equation="eq:product">
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<img src="https://cdn.jsdelivr.net/gh/stdlib-js/stdlib@e7ac225deb396ee6d2b4d5fc1a2faa645582349f/lib/node_modules/@stdlib/stats/iter/prod/docs/img/equation_product.svg" alt="Equation for the product.">
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<br>
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</div>
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<!-- </equation> -->
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</section>
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<!-- /.intro -->
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<!-- Package usage documentation. -->
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<section class="usage">
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## Usage
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```javascript
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var iterprod = require( '@stdlib/stats/iter/prod' );
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```
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#### iterprod( iterator )
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Computes the product of all [iterated][mdn-iterator-protocol] values.
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```javascript
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var array2iterator = require( '@stdlib/array/to-iterator' );
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var arr = array2iterator( [ -1.0, -2.0, -3.0, 4.0 ] );
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var p = iterprod( arr );
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// returns -24.0
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```
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</section>
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<!-- /.usage -->
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<!-- Package 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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## Notes
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- If an iterated value is non-numeric (including `NaN`), the returned [`iterator`][mdn-iterator-protocol] returns `NaN`. If non-numeric iterated values are possible, you are advised to provide an [`iterator`][mdn-iterator-protocol] which type checks and handles non-numeric values accordingly.
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- For iterators which can generate many values or which may output large numbers, care should be taken to prevent overflow.
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</section>
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<!-- /.notes -->
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<!-- Package usage examples. -->
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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 runif = require( '@stdlib/random/iter/uniform' );
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var iterprod = require( '@stdlib/stats/iter/prod' );
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// Create an iterator for generating uniformly distributed pseudorandom numbers:
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var rand = runif( -10.0, 10.0, {
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'seed': 1234,
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'iter': 100
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});
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// Compute the product:
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var p = iterprod( rand );
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// returns <number>
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console.log( 'Product: %d.', p );
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```
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</section>
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<!-- /.examples -->
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<!-- 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. -->
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<section class="references">
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</section>
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<!-- /.references -->
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<!-- Section for all links. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
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<section class="links">
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[mdn-iterator-protocol]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#The_iterator_protocol
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</section>
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<!-- /.links -->
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