feat: add ndarray/base/maybe-broadcast-arrays

Author: kgryte

lib/node_modules/@stdlib/ndarray/base/maybe-broadcast-arrays/README.md

@@ -0,0 +1,156 @@
+<!--
+
+@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.
+
+-->
+
+# maybeBroadcastArrays
+
+> Broadcast [ndarrays][@stdlib/ndarray/base/ctor] to a common shape.
+
+<!-- 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 maybeBroadcastArrays = require( '@stdlib/ndarray/base/maybe-broadcast-arrays' );
+```
+
+#### maybeBroadcastArrays( arrays )
+
+Broadcasts [ndarrays][@stdlib/ndarray/base/ctor] to a common shape.
+
+```javascript
+var array = require( '@stdlib/ndarray/array' );
+var zeros = require( '@stdlib/ndarray/zeros' );
+
+// Create a 2x2 ndarray:
+var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
+// returns <ndarray>
+
+// Create a 2x2x2 ndarray:
+var y = zeros( [ 2, 2, 2 ] );
+// returns <ndarray>
+
+// Broadcast to a common shape:
+var out = maybeBroadcastArrays( [ x, y ] );
+// returns [ <ndarray>, <ndarray> ]
+```
+
+</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">
+
+## Notes
+
+-   The function throws an error if a provided [broadcast-incompatible][@stdlib/ndarray/base/broadcast-shapes] ndarrays.
+-   If a provided [ndarray][@stdlib/ndarray/base/ctor] has a shape matching the common shape, the function returns the provided [ndarray][@stdlib/ndarray/base/ctor].
+-   If a provided [ndarray][@stdlib/ndarray/base/ctor] has a different (broadcast compatible) shape than the common shape, the function returns a new (base) [ndarray][@stdlib/ndarray/base/ctor] view of the provided [ndarray][@stdlib/ndarray/base/ctor]'s data. The view is typically **not** contiguous. As more than one element of a returned view may refer to the same memory location, writing to a view may affect multiple elements. If you need to write to a returned [ndarray][@stdlib/ndarray/base/ctor], copy the [ndarray][@stdlib/ndarray/base/ctor] **before** performing operations which may mutate elements.
+-   A returned [ndarray][@stdlib/ndarray/base/ctor] is a "base" [ndarray][@stdlib/ndarray/base/ctor], and, thus, a returned [ndarray][@stdlib/ndarray/base/ctor] view does not perform bounds checking or afford any of the guarantees of the non-base [ndarray][@stdlib/ndarray/ctor] constructor. The primary intent of this function is to broadcast ndarray-like objects within internal implementations and to do so with minimal overhead.
+
+</section>
+
+<!-- /.notes -->
+
+<!-- Package usage examples. -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var array = require( '@stdlib/ndarray/array' );
+var zeros = require( '@stdlib/ndarray/zeros' );
+var numel = require( '@stdlib/ndarray/base/numel' );
+var ind2sub = require( '@stdlib/ndarray/ind2sub' );
+var maybeBroadcastArrays = require( '@stdlib/ndarray/base/maybe-broadcast-arrays' );
+
+// Create a 2x2 array:
+var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
+// returns <ndarray>
+
+// Create a 3x2x2 array:
+var y = zeros( [ 3, 2, 2 ] );
+// returns <ndarray>
+
+// Broadcast arrays to a common shape:
+var out = maybeBroadcastArrays( [ x, y ] );
+// returns <ndarray>
+
+// Retrieve the common shape:
+var sh = out[ 0 ].shape;
+// returns [ 3, 2, 2 ]
+
+// Retrieve the number of elements:
+var N = numel( sh );
+
+// Loop through the array elements...
+var i;
+for ( i = 0; i < N; i++ ) {
+    console.log( 'X[%s] = %d', ind2sub( sh, i ).join( ', ' ), out[ 0 ].iget( i ) );
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- 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">
+
+</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/ndarray/ctor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/ctor
+
+[@stdlib/ndarray/base/ctor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/base/ctor
+
+[@stdlib/ndarray/base/broadcast-shapes]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/base/broadcast-shapes
+
+</section>
+
+<!-- /.links -->