feat: add ndarray/find

lib/node_modules/@stdlib/ndarray/find/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2024 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.
+
+-->
+
+# findElement
+
+> Return the first element in the [ndarray][@stdlib/ndarray/ctor] that passes a test implemented by a predicate function.
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var findElement = require( '@stdlib/ndarray/find' );
+```
+
+#### findElement( x\[, options], predicate\[, thisArg] )
+
+Return the first element in the [ndarray][@stdlib/ndarray/ctor] that passes a test implemented by a predicate function.
+
+<!-- eslint-disable no-invalid-this, max-len -->
+
+```javascript
+var Float64Array = require( '@stdlib/array/float64' );
+var ndarray = require( '@stdlib/ndarray/ctor' );
+var ndarray2array = require( '@stdlib/ndarray/to-array' );
+
+function predicate( z ) {
+    return z > 6.0;
+}
+
+var buffer = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
+var shape = [ 2, 3 ];
+var strides = [ 6, 1 ];
+var offset = 1;
+
+var x = ndarray( 'float64', buffer, shape, strides, offset, 'row-major' );
+// returns <ndarray>
+
+var arr = ndarray2array( x );
+// returns [ [ 2.0,  3.0,  4.0 ], [ 8.0, 9.0, 10.0 ] ]
+
+var y = findElement( x, predicate );
+// returns 8.0
+```
+
+The function accepts the following arguments:
+
+-   **x**: input [ndarray][@stdlib/ndarray/ctor].
+-   **options**: function options _(optional)_.
+-   **predicate**: predicate function.
+-   **thisArg**: predicate function execution context _(optional)_.
+
+The function accepts the following options:
+
+-   **order**: index iteration order. By default, the function iterates over elements according to the [layout order][@stdlib/ndarray/orders] of the provided [ndarray][@stdlib/ndarray/ctor]. Accordingly, for row-major input [ndarrays][@stdlib/ndarray/ctor], the last dimension indices increment fastest. For column-major input [ndarrays][@stdlib/ndarray/ctor], the first dimension indices increment fastest. To override the inferred order and ensure that indices increment in a specific manner, regardless of the input [ndarray][@stdlib/ndarray/ctor]'s layout order, explicitly set the iteration order. Note, however, that iterating according to an order which does not match that of the input [ndarray][@stdlib/ndarray/ctor] may, in some circumstances, result in performance degradation due to cache misses. Must be either `'row-major'` or `'column-major'`.
+
+By default, the output element's [data type][@stdlib/ndarray/dtypes] is inferred from the input [ndarray][@stdlib/ndarray/ctor].
+
+<!-- eslint-disable max-len -->
+
+```javascript
+var Float64Array = require( '@stdlib/array/float64' );
+var ndarray = require( '@stdlib/ndarray/ctor' );
+var ndarray2array = require( '@stdlib/ndarray/to-array' );
+
+function predicate( z ) {
+    return z > 3.0;
+}
+
+var buffer = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
+var shape = [ 2, 3 ];
+var strides = [ 6, 1 ];
+var offset = 1;
+
+var x = ndarray( 'float64', buffer, shape, strides, offset, 'row-major' );
+// returns <ndarray>
+
+var arr = ndarray2array( x );
+// returns [ [ 2.0,  3.0,  4.0 ], [ 8.0, 9.0, 10.0 ] ]
+
+var opts = {
+    'order': 'column-major'
+};
+var y = findElement( x, opts, predicate );
+// returns 8.0
+
+opts = {
+    'order': 'row-major'
+};
+y = findElement( x, opts, predicate );
+// returns 4.0
+```
+
+To set the `predicate` function execution context, provide a `thisArg`.
+
+<!-- eslint-disable no-invalid-this, max-len -->
+
+```javascript
+var Float64Array = require( '@stdlib/array/float64' );
+var ndarray = require( '@stdlib/ndarray/ctor' );
+var ndarray2array = require( '@stdlib/ndarray/to-array' );
+
+function predicate( z ) {
+    this.count += 1;
+    return z > 6.0;
+}
+
+var buffer = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
+var shape = [ 2, 3 ];
+var strides = [ 6, 1 ];
+var offset = 1;
+
+var x = ndarray( 'float64', buffer, shape, strides, offset, 'row-major' );
+// returns <ndarray>
+
+var arr = ndarray2array( x );
+// returns [ [ 2.0,  3.0,  4.0 ], [ 8.0, 9.0, 10.0 ] ]
+
+var ctx = {
+    'count': 0
+};
+var y = findElement( x, predicate, ctx );
+// returns 8.0
+
+var count = ctx.count;
+// returns 4
+```
+
+The `predicate` function is provided the following arguments:
+
+-   **value**: current array element.
+-   **indices**: current array element indices.
+-   **arr**: the input [ndarray][@stdlib/ndarray/ctor].
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   The function returns **NaN** if no element in ndarray passes test implemented by the predicate function.
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
+var ndarray2array = require( '@stdlib/ndarray/to-array' );
+var naryFunction = require( '@stdlib/utils/nary-function' );
+var array = require( '@stdlib/ndarray/array' );
+var isPositive = require( '@stdlib/assert/is-positive-number' ).isPrimitive;
+var findElement = require( '@stdlib/ndarray/find' );
+
+var buffer = discreteUniform( 10, -100, 100, {
+    'dtype': 'generic'
+});
+var x = array( buffer, {
+    'shape': [ 5, 2 ],
+    'dtype': 'generic'
+});
+console.log( ndarray2array( x ) );
+
+var y = findElement( x, naryFunction( isPositive, 1 ) );
+console.log( y );
+```
+
+</section>
+
+<!-- /.examples -->
+
+<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
+
+<section class="related">
+
+</section>
+
+<!-- /.related -->
+
+<section class="links">
+
+[@stdlib/ndarray/ctor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/ctor
+
+[@stdlib/ndarray/dtypes]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/dtypes
+
+[@stdlib/ndarray/orders]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/ndarray/orders
+
+<!-- <related-links> -->
+
+<!-- </related-links> -->
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/ndarray/find/benchmark/benchmark.1d.js

@@ -0,0 +1,142 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2024 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 isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pow = require( '@stdlib/math/base/special/pow' );
+var isInteger = require( '@stdlib/assert/is-integer' );
+var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
+var shape2strides = require( '@stdlib/ndarray/base/shape2strides' );
+var ndarray = require( '@stdlib/ndarray/ctor' );
+var pkg = require( './../package.json' ).name;
+var findElement = require( './../lib' );
+
+
+// VARIABLES //
+
+var xtypes = [ 'generic' ];
+var orders = [ 'row-major', 'column-major' ];
+
+
+// FUNCTIONS //
+
+/**
+* Predicate function.
+*
+* @private
+* @param {number} value - array element
+* @param {NonNegativeIntegerArray} indices - element indices
+* @param {ndarray} arr - input array
+* @returns {boolean} result
+*/
+function predicate( value ) {
+	return value > 0.0;
+}
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @param {NonNegativeIntegerArray} shape - ndarray shape
+* @param {string} xtype - input ndarray data type
+* @param {string} order - ndarray memory layout
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len, shape, xtype, order ) {
+	var strides;
+	var xbuf;
+	var x;
+
+	xbuf = discreteUniform( len, -100, 100, {
+		'dtype': xtype
+	});
+	strides = shape2strides( shape, order );
+	x = ndarray( xtype, xbuf, shape, strides, 0, order );
+
+	return benchmark;
+
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Benchmark} b - benchmark instance
+	*/
+	function benchmark( b ) {
+		var y;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			y = findElement( x, predicate );
+			if ( isnan( y ) ) {
+				b.fail( 'should not return NaN' );
+			}
+		}
+		b.toc();
+		if ( !isInteger( y ) ) {
+			b.fail( 'should return an ndarray' );
+		}
+		b.pass( 'benchmark finished' );
+		b.end();
+	}
+}
+
+
+// MAIN //
+
+/**
+* Main execution sequence.
+*
+* @private
+*/
+function main() {
+	var len;
+	var min;
+	var max;
+	var ord;
+	var sh;
+	var t1;
+	var f;
+	var i;
+	var j;
+	var k;
+
+	min = 1; // 10^min
+	max = 6; // 10^max
+
+	for ( k = 0; k < orders.length; k++ ) {
+		ord = orders[ k ];
+		for ( j = 0; j < xtypes.length; j++ ) {
+			t1 = xtypes[ j ];
+			for ( i = min; i <= max; i++ ) {
+				len = pow( 10, i );
+
+				sh = [ len ];
+				f = createBenchmark( len, sh, t1, ord );
+				bench( pkg+':ndims='+sh.length+',len='+len+',shape=['+sh.join(',')+'],xorder='+ord+',yorder='+ord+',xtype='+t1, f );
+			}
+		}
+	}
+}
+
+main();