feat: add blas/ext/base/greplicate

lib/node_modules/@stdlib/blas/ext/base/greplicate/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2026 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.
+
+-->
+
+# greplicate
+
+> Replicate each strided array element a specified number of times.
+
+<section class="intro">
+
+</section>
+
+<!-- /.intro -->
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var greplicate = require( '@stdlib/blas/ext/base/greplicate' );
+```
+
+#### greplicate( N, k, x, strideX, out, strideOut )
+
+Replicates each strided array element a specified number of times.
+
+```javascript
+var x = [ 1.0, 2.0, 3.0 ];
+var out = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ];
+
+greplicate( x.length, 2, x, 1, out, 1 );
+// out => [ 1.0, 1.0, 2.0, 2.0, 3.0, 3.0 ]
+```
+
+The function has the following parameters:
+
+-   **N**: number of indexed elements.
+-   **k**: number of times to replicate each element.
+-   **x**: input array.
+-   **strideX**: stride length for `x`.
+-   **out**: output array.
+-   **strideOut**: stride length for `out`.
+
+The `N` and stride parameters determine which elements in the strided arrays are accessed at runtime. For example, to replicate every other element:
+
+```javascript
+var x = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ];
+var out = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ];
+
+greplicate( 3, 2, x, 2, out, 1 );
+// out => [ 1.0, 1.0, 3.0, 3.0, 5.0, 5.0 ]
+```
+
+Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views.
+
+<!-- eslint-disable stdlib/capitalized-comments -->
+
+```javascript
+var Float64Array = require( '@stdlib/array/float64' );
+
+// Initial arrays...
+var x0 = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
+var out0 = new Float64Array( [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ] );
+
+// Create offset views...
+var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
+var out1 = new Float64Array( out0.buffer, out0.BYTES_PER_ELEMENT*2 ); // start at 3rd element
+
+greplicate( 3, 2, x1, 2, out1, 1 );
+// out0 => <Float64Array>[ 0.0, 0.0, 2.0, 2.0, 4.0, 4.0, 6.0, 6.0 ]
+```
+
+#### greplicate.ndarray( N, k, x, strideX, offsetX, out, strideOut, offsetOut )
+
+Replicates each strided array element a specified number of times using alternative indexing semantics.
+
+```javascript
+var x = [ 1.0, 2.0, 3.0 ];
+var out = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ];
+
+greplicate.ndarray( x.length, 2, x, 1, 0, out, 1, 0 );
+// out => [ 1.0, 1.0, 2.0, 2.0, 3.0, 3.0 ]
+```
+
+The function has the following additional parameters:
+
+-   **offsetX**: starting index for `x`.
+-   **offsetOut**: starting index for `out`.
+
+While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying buffer, offset parameters support indexing semantics based on starting indices. For example, to replicate every other element in the strided input array starting from the second element and to store in the last `N*k` elements of the strided output array starting from the last element:
+
+```javascript
+var x = [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ];
+var out = [ 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 ];
+
+greplicate.ndarray( 3, 2, x, 2, 1, out, -1, out.length-1 );
+// out => [ 0.0, 0.0, 6.0, 6.0, 4.0, 4.0, 2.0, 2.0 ]
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   If `N <= 0` or `k <= 0`, both functions return `out` unchanged.
+-   Both functions assume that the output array supports `N*k` indexed elements.
+-   Both functions support array-like objects having getter and setter accessors for array element access (e.g., [`@stdlib/array/base/accessor`][@stdlib/array/base/accessor]).
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
+var Float64Array = require( '@stdlib/array/float64' );
+var greplicate = require( '@stdlib/blas/ext/base/greplicate' );
+
+var x = discreteUniform( 10, -100, 100, {
+    'dtype': 'float64'
+});
+console.log( x );
+
+var out = new Float64Array( x.length * 3 );
+console.log( out );
+
+greplicate( x.length, 3, x, 1, out, 1 );
+console.log( out );
+```
+
+</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">
+
+[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
+
+[@stdlib/array/base/accessor]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/base/accessor
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/blas/ext/base/greplicate/benchmark/benchmark.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2026 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 uniform = require( '@stdlib/random/array/uniform' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pow = require( '@stdlib/math/base/special/pow' );
+var zeros = require( '@stdlib/array/zeros' );
+var format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var greplicate = require( './../lib/main.js' );
+
+
+// VARIABLES //
+
+var options = {
+	'dtype': 'generic'
+};
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var out = zeros( len * 2, options.dtype );
+	var x = uniform( len, -100, 100, options );
+	return benchmark;
+
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Benchmark} b - benchmark instance
+	*/
+	function benchmark( b ) {
+		var v;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			x[ 0 ] += 1.0;
+			v = greplicate( x.length, 2, x, 1, out, 1 );
+			if ( isnan( v[ i % ( len * 2 ) ] ) ) {
+				b.fail( 'should not return NaN' );
+			}
+		}
+		b.toc();
+		if ( isnan( v[ i % ( len * 2 ) ] ) ) {
+			b.fail( 'should not return NaN' );
+		}
+		b.pass( 'benchmark finished' );
+		b.end();
+	}
+}
+
+
+// MAIN //
+
+/**
+* Main execution sequence.
+*
+* @private
+*/
+function main() {
+	var len;
+	var min;
+	var max;
+	var f;
+	var i;
+
+	min = 1; // 10^min
+	max = 6; // 10^max
+
+	for ( i = min; i <= max; i++ ) {
+		len = pow( 10, i );
+		f = createBenchmark( len );
+		bench( format( '%s:len=%d', pkg, len ), f );
+	}
+}
+
+main();

lib/node_modules/@stdlib/blas/ext/base/greplicate/benchmark/benchmark.ndarray.js

@@ -0,0 +1,106 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2026 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 uniform = require( '@stdlib/random/array/uniform' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pow = require( '@stdlib/math/base/special/pow' );
+var zeros = require( '@stdlib/array/zeros' );
+var format = require( '@stdlib/string/format' );
+var pkg = require( './../package.json' ).name;
+var greplicate = require( './../lib/ndarray.js' );
+
+
+// VARIABLES //
+
+var options = {
+	'dtype': 'generic'
+};
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var out = zeros( len * 2, options.dtype );
+	var x = uniform( len, -100, 100, options );
+	return benchmark;
+
+	/**
+	* Benchmark function.
+	*
+	* @private
+	* @param {Benchmark} b - benchmark instance
+	*/
+	function benchmark( b ) {
+		var v;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			x[ 0 ] += 1.0;
+			v = greplicate( x.length, 2, x, 1, 0, out, 1, 0 );
+			if ( isnan( v[ i % ( len * 2 ) ] ) ) {
+				b.fail( 'should not return NaN' );
+			}
+		}
+		b.toc();
+		if ( isnan( v[ i % ( len * 2 ) ] ) ) {
+			b.fail( 'should not return NaN' );
+		}
+		b.pass( 'benchmark finished' );
+		b.end();
+	}
+}
+
+
+// MAIN //
+
+/**
+* Main execution sequence.
+*
+* @private
+*/
+function main() {
+	var len;
+	var min;
+	var max;
+	var f;
+	var i;
+
+	min = 1; // 10^min
+	max = 6; // 10^max
+
+	for ( i = min; i <= max; i++ ) {
+		len = pow( 10, i );
+		f = createBenchmark( len );
+		bench( format( '%s:ndarray:len=%d', pkg, len ), f );
+	}
+}
+
+main();