feat: add stats/base/ndarray/quantile

lib/node_modules/@stdlib/stats/base/ndarray/quantile/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2025 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.
+
+-->
+
+# quantile
+
+> Compute the p-th quantile of a sorted one-dimensional ndarray.
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var quantile = require( '@stdlib/stats/base/ndarray/quantile' );
+```
+
+#### quantile( arrays , p )
+
+Computes the p-th quantile of a sorted one-dimensional ndarray.
+
+```javascript
+var ndarray = require( '@stdlib/ndarray/base/ctor' );
+
+var xbuf = [ 1.0, 2.0, 3.0, 4.0 ];
+var x = new ndarray( 'generic', xbuf, [ 4 ], [ 1 ], 0, 'row-major' );
+
+var v = quantile( [x], 0.5 );
+// returns 2.5
+```
+
+The function has the following parameters:
+
+
+-   **arrays**: array-like object containing a sorted one-dimensional input ndarray.
+-   **p**: quantile probability in the interval 0 and 1.
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   If provided an empty ndarray, the function returns `NaN`.
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var linspace = require( '@stdlib/array/linspace' );
+var ndarray = require( '@stdlib/ndarray/base/ctor' );
+var ndarray2array = require( '@stdlib/ndarray/to-array' );
+var quantile = require( '@stdlib/stats/base/ndarray/quantile' );
+
+// Create a linearly spaced sorted array:
+var xbuf = linspace( 0.0, 10.0, 11 );
+
+var x = new ndarray( 'generic', xbuf, [ xbuf.length ], [ 1 ], 0, 'row-major' );
+console.log( ndarray2array( x ) );
+
+var v = quantile( [ x ], 0.5 );
+console.log( v );
+```
+
+</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">
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/stats/base/ndarray/quantile/benchmark/benchmark.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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';
+
+var bench = require( '@stdlib/bench' );
+var linspace = require( '@stdlib/array/linspace' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pow = require( '@stdlib/math/base/special/pow' );
+var ndarray = require( '@stdlib/ndarray/base/ctor' );
+var pkg = require( './../package.json' ).name;
+var quantile = require( './../lib' );
+
+var options = {
+	'dtype': 'generic'
+};
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var xbuf;
+	var x;
+
+	xbuf = linspace( 0.0, 100.0, len );
+	x = new ndarray( options.dtype, xbuf, [ len ], [ 1 ], 0, 'row-major' );
+
+	return benchmark;
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Object} b - benchmark instance
+	* @returns {void}
+	*/
+	function benchmark( b ) {
+		var v;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			v = quantile( [ x ], 0.5 );
+			if ( isnan( v ) ) {
+				b.fail( 'should not return NaN' );
+			}
+		}
+		b.toc();
+		if ( isnan( v ) ) {
+			b.fail( 'should not return NaN' );
+		}
+		b.pass( 'benchmark finished' );
+		b.end();
+	}
+}
+
+
+// MAIN //
+
+/**
+* Main execution sequence.
+*
+* @private
+* @returns {void}
+*/
+function main() {
+	var len;
+	var min;
+	var max;
+	var f;
+	var i;
+
+	min = 1; // 10^1
+	max = 6; // 10^6
+
+	for ( i = min; i <= max; i++ ) {
+		len = pow( 10, i );
+		f = createBenchmark( len );
+		bench( pkg+':len='+len, f );
+	}
+}
+
+main();

lib/node_modules/@stdlib/stats/base/ndarray/quantile/docs/repl.txt

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+{{alias}}( arrays, p )
+    Computes the p-th quantile of a sorted one-dimensional ndarray.
+
+    The quantile is the value below which a fraction `p` of the data falls.
+    The input array must be sorted in ascending order.
+
+    If provided an empty ndarray, the function returns `NaN`.
+
+    Parameters
+    ----------
+    arrays: ArrayLikeObject<ndarray>
+        Array-like object containing a sorted one-dimensional input ndarray.
+    p: number
+        Quantile probability in the interval [0,1].
+
+    Returns
+    -------
+    out: number
+        Quantile value.
+
+    Examples
+    --------
+    > var xbuf = [ 1.0, 2.0, 3.0, 4.0 ];
+    > var dt = 'generic';
+    > var sh = [ xbuf.length ];
+    > var sx = [ 1 ];
+    > var ox = 0;
+    > var ord = 'row-major';
+    > var x = new {{alias:@stdlib/ndarray/ctor}}( dt, xbuf, sh, sx, ox, ord );
+    > {{alias}}( [ x ], 0.5 )
+    2.5
+
+    See Also
+    --------

lib/node_modules/@stdlib/stats/base/ndarray/quantile/docs/types/index.d.ts

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+/*
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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.
+*/
+
+// TypeScript Version: 4.1
+
+/// <reference types="@stdlib/types"/>
+
+import { ndarray } from '@stdlib/types/ndarray';
+
+/**
+* Computes the p-th quantile of a sorted one-dimensional ndarray.
+*
+* @param arrays - array-like object containing a sorted input ndarray
+* @param p - quantile probability in the interval [0,1]
+* @returns quantile value
+*
+* @example
+* var ndarray = require( '@stdlib/ndarray/base/ctor' );
+*
+* var xbuf = [ 1.0, 2.0, 3.0, 4.0 ];
+* var x = new ndarray( 'generic', xbuf, [ 4 ], [ 1 ], 0, 'row-major' );
+*
+* var v = quantile( [ x ], 0.5 );
+* // returns ~2.5
+*/
+declare function quantile<T extends ndarray = ndarray>( arrays: [ T ], p: number ): number;
+
+
+// EXPORTS //
+
+export = quantile;

lib/node_modules/@stdlib/stats/base/ndarray/quantile/docs/types/test.ts

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+/*
+* @license Apache-2.0
+*
+* Copyright (c) 2025 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.
+*/
+
+/* eslint-disable space-in-parens */
+
+import zeros = require( '@stdlib/ndarray/zeros' );
+import quantile = require( './index' );
+
+
+// TESTS //
+
+// The function returns a number...
+{
+	const x = zeros( [ 10 ], {
+		'dtype': 'generic'
+	});
+
+	quantile( [ x ], 0.5 ); // $ExpectType number
+}
+
+// The compiler throws an error if the first argument is not an array of ndarrays...
+{
+	quantile( '10', 0.5 ); // $ExpectError
+	quantile( 10, 0.5 ); // $ExpectError
+	quantile( true, 0.5 ); // $ExpectError
+	quantile( false, 0.5 ); // $ExpectError
+	quantile( null, 0.5 ); // $ExpectError
+	quantile( undefined, 0.5 ); // $ExpectError
+	quantile( [], 0.5 ); // $ExpectError
+	quantile( {}, 0.5 ); // $ExpectError
+	quantile( (x: number): number => x, 0.5 ); // $ExpectError
+}
+
+// The compiler throws an error if the second argument is not a number...
+{
+	const x = zeros( [ 10 ], {
+		'dtype': 'generic'
+	});
+
+	quantile( [ x ], '0.5' ); // $ExpectError
+	quantile( [ x ], true ); // $ExpectError
+	quantile( [ x ], false ); // $ExpectError
+	quantile( [ x ], null ); // $ExpectError
+	quantile( [ x ], undefined ); // $ExpectError
+	quantile( [ x ], [] ); // $ExpectError
+	quantile( [ x ], {} ); // $ExpectError
+}
+
+// The compiler throws an error if the wrong number of arguments is provided...
+{
+	const x = zeros( [ 10 ], {
+		'dtype': 'generic'
+	});
+
+	quantile(); // $ExpectError
+	quantile( [ x ] ); // $ExpectError
+	quantile( [ x ], 0.5, {} ); // $ExpectError
+}