Add pkg to create an array containing pseudorandom numbers drawn from a beta distribution

Author: kgryte

lib/node_modules/@stdlib/random/array/beta/README.md

@@ -0,0 +1,352 @@
+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2023 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.
+
+-->
+
+# Beta Random Numbers
+
+> Create an array containing pseudorandom numbers drawn from a [beta][@stdlib/random/base/beta] distribution.
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var beta = require( '@stdlib/random/array/beta' );
+```
+
+#### beta( len, alpha, beta\[, options] )
+
+Returns an array containing pseudorandom numbers drawn from a [beta][@stdlib/random/base/beta] distribution.
+
+```javascript
+var out = beta( 10, 2.0, 5.0 );
+// returns <Float64Array>
+```
+
+The function has the following parameters:
+
+-   **len**: output array length.
+-   **alpha**: first shape parameter.
+-   **beta**: second shape parameter.
+-   **options**: function options.
+
+The function accepts the following `options`:
+
+-   **dtype**: output array data type. Must be a [real-valued floating-point data type][@stdlib/array/typed-real-float-dtypes] or "generic". Default: `'float64'`.
+
+By default, the function returns a [`Float64Array`][@stdlib/array/float64]. To return an array having a different data type, set the `dtype` option.
+
+```javascript
+var opts = {
+    'dtype': 'generic'
+};
+
+var out = beta( 10, 2.0, 5.0, opts );
+// returns [...]
+```
+
+#### beta.factory( \[alpha, beta, ]\[options] )
+
+Returns a function for creating arrays containing pseudorandom numbers drawn from a [beta][@stdlib/random/base/beta] distribution.
+
+```javascript
+var random = beta.factory();
+
+var out = random( 10, 2.0, 5.0 );
+// returns <Float64Array>
+
+var len = out.length;
+// returns 10
+```
+
+If provided `alpha` and `beta`, the returned generator returns random variates from the specified distribution.
+
+```javascript
+var random = beta.factory( 2.0, 5.0 );
+
+var out = random( 10 );
+// returns <Float64Array>
+
+out = random( 10 );
+// returns <Float64Array>
+```
+
+If not provided `alpha` and `beta`, the returned generator requires that both parameters be provided at each invocation.
+
+```javascript
+var random = beta.factory();
+
+var out = random( 10, 2.0, 5.0 );
+// returns <Float64Array>
+
+out = random( 10, 2.0, 5.0 );
+// returns <Float64Array>
+```
+
+The function accepts the following `options`:
+
+-   **prng**: pseudorandom number generator for generating uniformly distributed pseudorandom numbers on the interval `[0,1)`. If provided, the function **ignores** both the `state` and `seed` options. In order to seed the underlying pseudorandom number generator, one must seed the provided `prng` (assuming the provided `prng` is seedable).
+-   **seed**: pseudorandom number generator seed.
+-   **state**: a [`Uint32Array`][@stdlib/array/uint32] containing pseudorandom number generator state. If provided, the function ignores the `seed` option.
+-   **copy**: `boolean` indicating whether to copy a provided pseudorandom number generator state. Setting this option to `false` allows sharing state between two or more pseudorandom number generators. Setting this option to `true` ensures that an underlying generator has exclusive control over its internal state. Default: `true`.
+-   **dtype**: default output array data type. Must be a [real-valued floating-point data type][@stdlib/array/typed-real-float-dtypes] or "generic". Default: `'float64'`.
+
+To use a custom PRNG as the underlying source of uniformly distributed pseudorandom numbers, set the `prng` option.
+
+```javascript
+var minstd = require( '@stdlib/random/base/minstd' );
+
+var opts = {
+    'prng': minstd.normalized
+};
+var random = beta.factory( 2.0, 5.0, opts );
+
+var out = random( 10 );
+// returns <Float64Array>
+```
+
+To seed the underlying pseudorandom number generator, set the `seed` option.
+
+```javascript
+var opts = {
+    'seed': 12345
+};
+var random = beta.factory( 2.0, 5.0, opts );
+
+var out = random( 10, opts );
+// returns <Float64Array>
+```
+
+The returned function accepts the following `options`:
+
+-   **dtype**: output array data type. Must be a [real-valued floating-point data type][@stdlib/array/typed-real-float-dtypes] or "generic". This overrides the default output array data type.
+
+To override the default output array data type, set the `dtype` option.
+
+```javascript
+var random = beta.factory( 2.0, 5.0 );
+
+var out = random( 10 );
+// returns <Float64Array>
+
+var opts = {
+    'dtype': 'generic'
+};
+out = random( 10, opts );
+// returns [...]
+```
+
+#### beta.PRNG
+
+The underlying pseudorandom number generator.
+
+```javascript
+var prng = beta.PRNG;
+// returns <Function>
+```
+
+#### beta.seed
+
+The value used to seed the underlying pseudorandom number generator.
+
+```javascript
+var seed = beta.seed;
+// returns <Uint32Array>
+```
+
+If the `factory` method is provided a PRNG for uniformly distributed numbers, the associated property value on the returned function is `null`.
+
+```javascript
+var minstd = require( '@stdlib/random/base/minstd-shuffle' ).normalized;
+
+var random = beta.factory( 2.0, 5.0, {
+    'prng': minstd
+});
+
+var seed = random.seed;
+// returns null
+```
+
+#### beta.seedLength
+
+Length of underlying pseudorandom number generator seed.
+
+```javascript
+var len = beta.seedLength;
+// returns <number>
+```
+
+If the `factory` method is provided a PRNG for uniformly distributed numbers, the associated property value on the returned function is `null`.
+
+```javascript
+var minstd = require( '@stdlib/random/base/minstd-shuffle' ).normalized;
+
+var random = beta.factory( 2.0, 5.0, {
+    'prng': minstd
+});
+
+var len = random.seedLength;
+// returns null
+```
+
+#### beta.state
+
+Writable property for getting and setting the underlying pseudorandom number generator state.
+
+```javascript
+var state = beta.state;
+// returns <Uint32Array>
+```
+
+If the `factory` method is provided a PRNG for uniformly distributed numbers, the associated property value on the returned function is `null`.
+
+```javascript
+var minstd = require( '@stdlib/random/base/minstd-shuffle' ).normalized;
+
+var random = beta.factory( 2.0, 5.0, {
+    'prng': minstd
+});
+
+var state = random.state;
+// returns null
+```
+
+#### beta.stateLength
+
+Length of underlying pseudorandom number generator state.
+
+```javascript
+var len = beta.stateLength;
+// returns <number>
+```
+
+If the `factory` method is provided a PRNG for uniformly distributed numbers, the associated property value on the returned function is `null`.
+
+```javascript
+var minstd = require( '@stdlib/random/base/minstd-shuffle' ).normalized;
+
+var random = beta.factory( 2.0, 5.0, {
+    'prng': minstd
+});
+
+var len = random.stateLength;
+// returns null
+```
+
+#### beta.byteLength
+
+Size (in bytes) of underlying pseudorandom number generator state.
+
+```javascript
+var sz = beta.byteLength;
+// returns <number>
+```
+
+If the `factory` method is provided a PRNG for uniformly distributed numbers, the associated property value on the returned function is `null`.
+
+```javascript
+var minstd = require( '@stdlib/random/base/minstd-shuffle' ).normalized;
+
+var random = beta.factory( 2.0, 5.0, {
+    'prng': minstd
+});
+
+var sz = random.byteLength;
+// returns null
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   If PRNG state is "shared" (meaning a state array was provided during function creation and **not** copied) and one sets the underlying generator state to a state array having a different length, the function returned by the `factory` method does **not** update the existing shared state and, instead, points to the newly provided state array. In order to synchronize the output of the underlying generator according to the new shared state array, the state array for **each** relevant creation function and/or PRNG must be **explicitly** set.
+-   If PRNG state is "shared" and one sets the underlying generator state to a state array of the same length, the PRNG state is updated (along with the state of all other creation functions and/or PRNGs sharing the PRNG's state array).
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var logEach = require( '@stdlib/console/log-each' );
+var beta = require( '@stdlib/random/array/beta' );
+
+// Create a function for generating random arrays originating from the same state:
+var random = beta.factory( 2.0, 5.0, {
+    'state': beta.state,
+    'copy': true
+});
+
+// Generate 3 arrays:
+var x1 = random( 5 );
+var x2 = random( 5 );
+var x3 = random( 5 );
+
+// Print the contents:
+logEach( '%f, %f, %f', x1, x2, x3 );
+
+// Create another function for generating random arrays with the original state:
+random = beta.factory( 2.0, 5.0, {
+    'state': beta.state,
+    'copy': true
+});
+
+// Generate a single array which replicates the above pseudorandom number generation sequence:
+var x4 = random( 15 );
+
+// Print the contents:
+logEach( '%f', x4 );
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- 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">
+
+[@stdlib/random/base/beta]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/random/base/beta
+
+[@stdlib/array/typed-real-float-dtypes]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/typed-real-float-dtypes
+
+[@stdlib/array/uint32]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/uint32
+
+[@stdlib/array/float64]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/float64
+
+</section>
+
+<!-- /.links -->