feat: add C ndarray API and refactor blas/ext/base/drev

PR-URL: #3071

Reviewed-by: Philipp Burckhardt <[email protected]>

Author: headlessNode

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

@@ -30,7 +30,7 @@ limitations under the License.
 var drev = require( '@stdlib/blas/ext/base/drev' );
 ```
 
-#### drev( N, x, stride )
+#### drev( N, x, strideX )
 
 Reverses a double-precision floating-point strided array `x` in-place.
 
@@ -47,9 +47,9 @@ The function has the following parameters:
 
 -   **N**: number of indexed elements.
 -   **x**: input [`Float64Array`][@stdlib/array/float64].
--   **stride**: index increment.
+-   **strideX**: stride length for `x`.
 
-The `N` and stride parameters determine which elements in the strided array are accessed at runtime. For example, to reverse every other element
+The `N` and stride parameters determine which elements in the strided array are accessed at runtime. For example, to reverse every other element:
 
 ```javascript
 var Float64Array = require( '@stdlib/array/float64' );
@@ -76,7 +76,7 @@ drev( 3, x1, 2 );
 // x0 => <Float64Array>[ 1.0, -6.0, 3.0, -4.0, 5.0, -2.0 ]
 ```
 
-#### drev.ndarray( N, x, stride, offset )
+#### drev.ndarray( N, x, strideX, offsetX )
 
 Reverses a double-precision floating-point strided array `x` in-place using alternative indexing semantics.
 
@@ -91,9 +91,9 @@ drev.ndarray( x.length, x, 1, 0 );
 
 The function has the following additional parameters:
 
--   **offset**: starting index.
+-   **offsetX**: starting index for `x`.
 
-While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying `buffer`, the `offset` parameter supports indexing semantics based on a starting index. For example, to access only the last three elements of the strided array
+While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying buffer, the offset parameter supports indexing semantics based on a starting index. For example, to access only the last three elements of the strided array:
 
 ```javascript
 var Float64Array = require( '@stdlib/array/float64' );
@@ -126,11 +126,12 @@ drev.ndarray( 3, x, 1, x.length-3 );
 <!-- eslint no-undef: "error" -->
 
 ```javascript
-var discreteUniform = require( '@stdlib/random/base/discrete-uniform' ).factory;
-var filledarrayBy = require( '@stdlib/array/filled-by' );
+var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
 var drev = require( '@stdlib/blas/ext/base/drev' );
 
-var x = filledarrayBy( 10, 'float64', discreteUniform( -100.0, 100.0 ) );
+var x = discreteUniform( 10, -100, 100, {
+    'dtype': 'float64'
+});
 console.log( x );
 
 drev( x.length, x, 1 );
@@ -141,6 +142,123 @@ console.log( x );
 
 <!-- /.examples -->
 
+<!-- C interface documentation. -->
+
+* * *
+
+<section class="c">
+
+## C APIs
+
+<!-- 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 -->
+
+<!-- C usage documentation. -->
+
+<section class="usage">
+
+### Usage
+
+```c
+#include "stdlib/blas/ext/base/drev.h"
+```
+
+#### stdlib_strided_drev( N, \*X, strideX )
+
+Reverses a double-precision floating-point strided array `X` in-place.
+
+```c
+double x[] = { 1.0, 2.0, 3.0, 4.0 };
+
+stdlib_strided_drev( 4, x, 1 );
+```
+
+The function accepts the following arguments:
+
+-   **N**: `[in] CBLAS_INT` number of indexed elements.
+-   **X**: `[in] double*` input array.
+-   **strideX**: `[in] CBLAS_INT` stride length for `X`.
+
+```c
+double stdlib_strided_drev( const CBLAS_INT N, double *X, const CBLAS_INT strideX );
+```
+
+#### stdlib_strided_drev_ndarray( N, \*X, strideX, offsetX )
+
+Reverses a double-precision floating-point strided array `X` in-place using alternative indexing semantics.
+
+```c
+double x[] = { 1.0, 2.0, 3.0, 4.0 };
+
+stdlib_strided_drev_ndarray( 4, x, 1, 0 );
+```
+
+The function accepts the following arguments:
+
+-   **N**: `[in] CBLAS_INT` number of indexed elements.
+-   **X**: `[in] double*` input array.
+-   **strideX**: `[in] CBLAS_INT` stride length for `X`.
+-   **offsetX**: `[in] CBLAS_INT` starting index for `X`.
+
+```c
+void stdlib_strided_drev_ndarray( const CBLAS_INT N, double *X, const CBLAS_INT strideX, const CBLAS_INT offsetX );
+```
+
+</section>
+
+<!-- /.usage -->
+
+<!-- C API usage notes. Make sure to keep an empty line after the `section` element and another before the `/section` close. -->
+
+<section class="notes">
+
+</section>
+
+<!-- /.notes -->
+
+<!-- C API usage examples. -->
+
+<section class="examples">
+
+### Examples
+
+```c
+#include "stdlib/blas/ext/base/drev.h"
+#include <stdio.h>
+
+int main( void ) {
+    // Create a strided array:
+    double x[] = { 1.0, -2.0, 3.0, -4.0, 5.0, -6.0, 7.0, -8.0 };
+
+    // Specify the number of elements:
+    const int N = 8;
+
+    // Specify a stride:
+    const int strideX = 1;
+
+    // Reverse the array:
+    stdlib_strided_drev( N, x, strideX );
+
+    // Print the result:
+    for ( int i = 0; i < 8; i++ ) {
+        printf( "x[ %i ] = %lf\n", i, x[ i ] );
+    }
+}
+```
+
+</section>
+
+<!-- /.examples -->
+
+</section>
+
+<!-- /.c -->
+
 <!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
 
 <section class="related">

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

@@ -21,8 +21,7 @@
 // MODULES //
 
 var bench = require( '@stdlib/bench' );
-var uniform = require( '@stdlib/random/base/uniform' ).factory;
-var filledarrayBy = require( '@stdlib/array/filled-by' );
+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 pkg = require( './../package.json' ).name;
@@ -31,7 +30,9 @@ var drev = require( './../lib/drev.js' );
 
 // VARIABLES //
 
-var rand = uniform( -10.0, 10.0 );
+var options = {
+	'dtype': 'float64'
+};
 
 
 // FUNCTIONS //
@@ -44,7 +45,7 @@ var rand = uniform( -10.0, 10.0 );
 * @returns {Function} benchmark function
 */
 function createBenchmark( len ) {
-	var x = filledarrayBy( len, 'float64', rand );
+	var x = uniform( len, -10.0, 10.0, options );
 	return benchmark;
 
 	function benchmark( b ) {

lib/node_modules/@stdlib/blas/ext/base/drev/benchmark/benchmark.native.js

@@ -22,8 +22,7 @@
 
 var resolve = require( 'path' ).resolve;
 var bench = require( '@stdlib/bench' );
-var uniform = require( '@stdlib/random/base/uniform' ).factory;
-var filledarrayBy = require( '@stdlib/array/filled-by' );
+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 tryRequire = require( '@stdlib/utils/try-require' );
@@ -36,7 +35,9 @@ var drev = tryRequire( resolve( __dirname, './../lib/drev.native.js' ) );
 var opts = {
 	'skip': ( drev instanceof Error )
 };
-var rand = uniform( -10.0, 10.0 );
+var options = {
+	'dtype': 'float64'
+};
 
 
 // FUNCTIONS //
@@ -49,7 +50,7 @@ var rand = uniform( -10.0, 10.0 );
 * @returns {Function} benchmark function
 */
 function createBenchmark( len ) {
-	var x = filledarrayBy( len, 'float64', rand );
+	var x = uniform( len, -10.0, 10.0, options );
 	return benchmark;
 
 	function benchmark( b ) {

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

@@ -21,8 +21,7 @@
 // MODULES //
 
 var bench = require( '@stdlib/bench' );
-var uniform = require( '@stdlib/random/base/uniform' ).factory;
-var filledarrayBy = require( '@stdlib/array/filled-by' );
+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 pkg = require( './../package.json' ).name;
@@ -31,7 +30,9 @@ var drev = require( './../lib/ndarray.js' );
 
 // VARIABLES //
 
-var rand = uniform( -10.0, 10.0 );
+var options = {
+	'dtype': 'float64'
+};
 
 
 // FUNCTIONS //
@@ -44,7 +45,7 @@ var rand = uniform( -10.0, 10.0 );
 * @returns {Function} benchmark function
 */
 function createBenchmark( len ) {
-	var x = filledarrayBy( len, 'float64', rand );
+	var x = uniform( len, -10.0, 10.0, options );
 	return benchmark;
 
 	function benchmark( b ) {

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

@@ -22,8 +22,7 @@
 
 var resolve = require( 'path' ).resolve;
 var bench = require( '@stdlib/bench' );
-var uniform = require( '@stdlib/random/base/uniform' ).factory;
-var filledarrayBy = require( '@stdlib/array/filled-by' );
+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 tryRequire = require( '@stdlib/utils/try-require' );
@@ -36,7 +35,9 @@ var drev = tryRequire( resolve( __dirname, './../lib/ndarray.native.js' ) );
 var opts = {
 	'skip': ( drev instanceof Error )
 };
-var rand = uniform( -10.0, 10.0 );
+var options = {
+	'dtype': 'float64'
+};
 
 
 // FUNCTIONS //
@@ -49,7 +50,7 @@ var rand = uniform( -10.0, 10.0 );
 * @returns {Function} benchmark function
 */
 function createBenchmark( len ) {
-	var x = filledarrayBy( len, 'float64', rand );
+	var x = uniform( len, -10.0, 10.0, options );
 	return benchmark;
 
 	function benchmark( b ) {

lib/node_modules/@stdlib/blas/ext/base/drev/benchmark/c/benchmark.length.c

@@ -94,7 +94,7 @@ static double rand_double( void ) {
 * @param len          array length
 * @return elapsed time in seconds
 */
-static double benchmark( int iterations, int len ) {
+static double benchmark1( int iterations, int len ) {
 	double elapsed;
 	double x[ len ];
 	double t;
@@ -105,7 +105,38 @@ static double benchmark( int iterations, int len ) {
 	}
 	t = tic();
 	for ( i = 0; i < iterations; i++ ) {
-		c_drev( len, x, 1 );
+		stdlib_strided_drev( len, x, 1 );
+		if ( x[ 0 ] != x[ 0 ] ) {
+			printf( "should not return NaN\n" );
+			break;
+		}
+	}
+	elapsed = tic() - t;
+	if ( x[ 0 ] != x[ 0 ] ) {
+		printf( "should not return NaN\n" );
+	}
+	return elapsed;
+}
+
+/**
+* Runs a benchmark.
+*
+* @param iterations   number of iterations
+* @param len          array length
+* @return elapsed time in seconds
+*/
+static double benchmark2( int iterations, int len ) {
+	double elapsed;
+	double x[ len ];
+	double t;
+	int i;
+
+	for ( i = 0; i < len; i++ ) {
+		x[ i ] = ( rand_double()*200.0 ) - 100.0;
+	}
+	t = tic();
+	for ( i = 0; i < iterations; i++ ) {
+		stdlib_strided_drev_ndarray( len, x, 1, 0 );
 		if ( x[ 0 ] != x[ 0 ] ) {
 			printf( "should not return NaN\n" );
 			break;
@@ -140,7 +171,18 @@ int main( void ) {
 		for ( j = 0; j < REPEATS; j++ ) {
 			count += 1;
 			printf( "# c::%s:len=%d\n", NAME, len );
-			elapsed = benchmark( iter, len );
+			elapsed = benchmark1( iter, len );
+			print_results( iter, elapsed );
+			printf( "ok %d benchmark finished\n", count );
+		}
+	}
+	for ( i = MIN; i <= MAX; i++ ) {
+		len = pow( 10, i );
+		iter = ITERATIONS / pow( 10, i-1 );
+		for ( j = 0; j < REPEATS; j++ ) {
+			count += 1;
+			printf( "# c::%s:ndarray:len=%d\n", NAME, len );
+			elapsed = benchmark2( iter, len );
 			print_results( iter, elapsed );
 			printf( "ok %d benchmark finished\n", count );
 		}