Add level 1 routine ddot

lib/node_modules/@stdlib/blas/base/ddot/README.md

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+<!--
+
+@license Apache-2.0
+
+Copyright (c) 2019 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.
+
+-->
+
+# ddot
+
+> Calculate the dot product of `x` and `y`.
+
+<section class="usage">
+
+## Usage
+
+```javascript
+var ddot = require( '@stdlib/blas/base/ddot' );
+```
+
+#### ddot( N, x, strideX, y, strideY )
+
+Calculates the dot product of vectors `x` and `y`.
+
+```javascript
+var Float64Array = require( '@stdlib/array/float64' );
+
+var x = new Float64Array( [ 4.0, 2.0, -3.0, 5.0, -1.0 ] );
+var y = new Float64Array( [ 2.0, 6.0, -1.0, -4.0, 8.0 ] );
+
+var z = ddot( x.length, x, 1, y, 1 );
+// returns -5.0
+```
+
+The function accepts the following parameters:
+
+-   **N**: number of indexed elements.
+-   **x**: input [`Float64Array`][@stdlib/array/float64].
+-   **strideX**: index increment for `x`.
+-   **y**: input [`Float64Array`][@stdlib/array/float64].
+-   **strideY**: index increment for `y`.
+
+The `N` and `stride` parameters determine which elements in `x` and `y` are accessed at runtime. For example, to calculate the dot product of every other value in `x` and the first `N` elements of `y` in reverse order,
+
+```javascript
+var Float64Array = require( '@stdlib/array/float64' );
+var floor = require( '@stdlib/math/base/special/floor' );
+
+var x = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
+var y = new Float64Array( [ 1.0, 1.0, 1.0, 1.0, 1.0, 1.0 ] );
+
+var N = floor( x.length / 2 );
+
+var z = ddot( N, x, 2, y, -1 );
+// returns 9.0
+```
+
+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' );
+var floor = require( '@stdlib/math/base/special/floor' );
+
+// Initial arrays...
+var x0 = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
+var y0 = new Float64Array( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
+
+// Create offset views...
+var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
+var y1 = new Float64Array( y0.buffer, y0.BYTES_PER_ELEMENT*3 ); // start at 4th element
+
+var N = floor( x0.length / 2 );
+
+var z = ddot( N, x1, -2, y1, 1 );
+// returns 128.0
+```
+
+#### ddot.ndarray( N, x, strideX, offsetX, y, strideY, offsetY )
+
+Calculates the dot product of `x` and `y`, with alternative indexing semantics.
+
+```javascript
+var Float64Array = require( '@stdlib/array/float64' );
+
+var x = new Float64Array( [ 4.0, 2.0, -3.0, 5.0, -1.0 ] );
+var y = new Float64Array( [ 2.0, 6.0, -1.0, -4.0, 8.0 ] );
+
+var z = ddot.ndarray( x.length, x, 1, 0, y, 1, 0 );
+// returns -5.0
+```
+
+The function accepts the following additional parameters:
+
+-   **offsetX**: starting index for `x`.
+-   **offsetY**: starting index for `y`.
+
+While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying `buffer`, the `offsetX` and `offsetY` parameters support indexing semantics based on starting indices. For example, to calculate the dot product of every other value in `x` starting from the second value with the last 3 elements in `y` in reverse order
+
+```javascript
+var Float64Array = require( '@stdlib/array/float64' );
+var floor = require( '@stdlib/math/base/special/floor' );
+
+var x = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 ] );
+var y = new Float64Array( [ 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
+
+var N = floor( x.length / 2 );
+
+var z = ddot.ndarray( N, x, 2, 1, y, -1, y.length-1 );
+// returns 128.0
+```
+
+</section>
+
+<!-- /.usage -->
+
+<section class="notes">
+
+## Notes
+
+-   If `N <= 0` both functions return `0.0`.
+-   `ddot()` corresponds to the [BLAS][blas] level 1 function [`ddot`][ddot].
+
+</section>
+
+<!-- /.notes -->
+
+<section class="examples">
+
+## Examples
+
+<!-- eslint no-undef: "error" -->
+
+```javascript
+var randu = require( '@stdlib/random/base/randu' );
+var round = require( '@stdlib/math/base/special/round' );
+var Float64Array = require( '@stdlib/array/float64' );
+var ddot = require( '@stdlib/blas/base/ddot' );
+
+var x;
+var y;
+var i;
+
+x = new Float64Array( 10 );
+y = new Float64Array( 10 );
+for ( i = 0; i < x.length; i++ ) {
+    x[ i ] = round( randu() * 100.0 );
+    y[ i ] = round( randu() * 10.0 );
+}
+console.log( x );
+console.log( y );
+
+var z = ddot( x.length, x, 1, y, -1 );
+console.log( z );
+```
+
+</section>
+
+<!-- /.examples -->
+
+<section class="links">
+
+[blas]: http://www.netlib.org/blas
+
+[ddot]: http://www.netlib.org/lapack/explore-html/df/d28/group__single__blas__level1.html
+
+[@stdlib/array/float64]: https://github.com/stdlib-js/stdlib
+
+[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
+
+</section>
+
+<!-- /.links -->

lib/node_modules/@stdlib/blas/base/ddot/benchmark/benchmark.js

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+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2019 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 randu = require( '@stdlib/random/base/randu' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pow = require( '@stdlib/math/base/special/pow' );
+var Float64Array = require( '@stdlib/array/float64' );
+var pkg = require( './../package.json' ).name;
+var ddot = require( './../lib/main.js' );
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var x;
+	var y;
+	var i;
+
+	x = new Float64Array( len );
+	y = new Float64Array( len );
+	for ( i = 0; i < x.length; i++ ) {
+		x[ i ] = ( randu()*10.0 ) - 20.0;
+		y[ i ] = ( randu()*10.0 ) - 20.0;
+	}
+	return benchmark;
+
+	function benchmark( b ) {
+		var d;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			d = ddot( x.length, x, 1, y, 1 );
+			if ( isnan( d ) ) {
+				b.fail( 'should not return NaN' );
+			}
+		}
+		b.toc();
+		if ( isnan( d ) ) {
+			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( pkg+':len='+len, f );
+	}
+}
+
+main();

lib/node_modules/@stdlib/blas/base/ddot/benchmark/benchmark.ndarray.js

@@ -0,0 +1,99 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2019 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 randu = require( '@stdlib/random/base/randu' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var pow = require( '@stdlib/math/base/special/pow' );
+var Float64Array = require( '@stdlib/array/float64' );
+var pkg = require( './../package.json' ).name;
+var ddot = require( './../lib/main.js' ).ndarray;
+
+
+// FUNCTIONS //
+
+/**
+* Creates a benchmark function.
+*
+* @private
+* @param {PositiveInteger} len - array length
+* @returns {Function} benchmark function
+*/
+function createBenchmark( len ) {
+	var x;
+	var y;
+	var i;
+
+	x = new Float64Array( len );
+	y = new Float64Array( len );
+	for ( i = 0; i < x.length; i++ ) {
+		x[ i ] = ( randu()*10.0 ) - 20.0;
+		y[ i ] = ( randu()*10.0 ) - 20.0;
+	}
+	return benchmark;
+
+	function benchmark( b ) {
+		var d;
+		var i;
+
+		b.tic();
+		for ( i = 0; i < b.iterations; i++ ) {
+			d = ddot( x.length, x, 1, 0, y, 1, 0 );
+			if ( isnan( d ) ) {
+				b.fail( 'should not return NaN' );
+			}
+		}
+		b.toc();
+		if ( isnan( d ) ) {
+			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( pkg+':ndarray:len='+len, f );
+	}
+}
+
+main();