feat: add C ndarray implementation for blas/base/sswap and blas/base/dswap

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

@@ -195,24 +195,49 @@ console.log( y );
 Interchanges two double-precision floating-point vectors.
 
 ```c
-double x[] = { 1.0, 2.0, 3.0, 4.0 };
-double y[] = { 0.0, 0.0, 0.0, 0.0 };
+double x[] = { 1.0, 2.0, 3.0, 4.0, 5.0 };
+double y[] = { 6.0, 7.0, 8.0, 9.0, 10.0 };
 
-c_dswap( 4, x, 1, y, 1 );
+c_dswap( 5, x, 1, y, 1 );
 ```
 
 The function accepts the following arguments:
 
 -   **N**: `[in] CBLAS_INT` number of indexed elements.
 -   **X**: `[inout] double*` first input array.
 -   **strideX**: `[in] CBLAS_INT` index increment for `X`.
--   **Y**: `[inout] double*` first input array.
+-   **Y**: `[inout] double*` second input array.
 -   **strideY**: `[in] CBLAS_INT` index increment for `Y`.
 
 ```c
 void c_dswap( const CBLAS_INT N, double *X, const CBLAS_INT strideX, double *Y, const CBLAS_INT strideY );
 ```
 
+#### c_dswap_ndarray( N, \*X, strideX, offsetX, \*Y, strideY, offsetY )
+
+Interchanges two double-precision floating-point vectors using alternative indexing semantics.
+
+```c
+double x[] = { 1.0, 2.0, 3.0, 4.0, 5.0 };
+double y[] = { 6.0, 7.0, 8.0, 9.0, 10.0 };
+
+c_dswap_ndarray( 3, x, 1, 2, y, 1, 2 );
+```
+
+The function accepts the following arguments:
+
+-   **N**: `[in] CBLAS_INT` number of indexed elements.
+-   **X**: `[inout] double*` first input array.
+-   **strideX**: `[in] CBLAS_INT` index increment for `X`.
+-   **offsetX**: `[in] CBLAS_INT` starting index for `X`.
+-   **Y**: `[inout] double*` second input array.
+-   **strideY**: `[in] CBLAS_INT` index increment for `Y`.
+-   **offsetY**: `[in] CBLAS_INT` starting index for `Y`.
+
+```c
+void c_dswap_ndarray( const CBLAS_INT N, double *X, const CBLAS_INT strideX, const CBLAS_INT offsetX, double *Y, const CBLAS_INT strideY, const CBLAS_INT offsetY );
+```
+
 </section>
 
 <!-- /.usage -->
@@ -240,7 +265,7 @@ int main( void ) {
     double x[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 };
     double y[] = { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 };
 
-    // Specify the number of elements:
+    // Specify the number of indexed elements:
     const int N = 4;
 
     // Specify stride lengths:
@@ -252,8 +277,17 @@ int main( void ) {
 
     // Print the result:
     for ( int i = 0; i < 8; i++ ) {
-        printf( "x[ %i ] = %lf\n", i, x[ i ] );
-        printf( "y[ %i ] = %lf\n", i, y[ i ] );
+        printf( "x[ %i ] = %f\n", i, x[ i ] );
+        printf( "y[ %i ] = %f\n", i, y[ i ] );
+    }
+
+    // Interchange elements:
+    c_dswap_ndarray( N, x, strideX, 0, y, strideY, 6 );
+
+    // Print the result:
+    for ( int i = 0; i < 8; i++ ) {
+        printf( "x[ %i ] = %f\n", i, x[ i ] );
+        printf( "y[ %i ] = %f\n", i, y[ i ] );
     }
 }
 ```
@@ -270,15 +304,6 @@ int main( void ) {
 
 <section class="related">
 
-* * *
-
-## See Also
-
--   <span class="package-name">[`@stdlib/blas/base/dcopy`][@stdlib/blas/base/dcopy]</span><span class="delimiter">: </span><span class="description">copy values from x into y.</span>
--   <span class="package-name">[`@stdlib/blas/base/gswap`][@stdlib/blas/base/gswap]</span><span class="delimiter">: </span><span class="description">interchange two vectors.</span>
--   <span class="package-name">[`@stdlib/blas/base/sswap`][@stdlib/blas/base/sswap]</span><span class="delimiter">: </span><span class="description">interchange two single-precision floating-point vectors.</span>
--   <span class="package-name">[`@stdlib/blas/dswap`][@stdlib/blas/dswap]</span><span class="delimiter">: </span><span class="description">interchange two double-precision floating-point vectors.</span>
-
 </section>
 
 <!-- /.related -->
@@ -295,18 +320,6 @@ int main( void ) {
 
 [mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
 
-<!-- <related-links> -->
-
-[@stdlib/blas/base/dcopy]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/blas/base/dcopy
-
-[@stdlib/blas/base/gswap]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/blas/base/gswap
-
-[@stdlib/blas/base/sswap]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/blas/base/sswap
-
-[@stdlib/blas/dswap]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/blas/dswap
-
-<!-- </related-links> -->
-
 </section>
 
 <!-- /.links -->

lib/node_modules/@stdlib/blas/base/dswap/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 y[ len ];
@@ -120,6 +120,39 @@ static double benchmark( int iterations, int len ) {
 	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 y[ len ];
+	double t;
+	int i;
+
+	for ( i = 0; i < len; i++ ) {
+		x[ i ] = ( rand_double()*20000.0 ) - 10000.0;
+		y[ i ] = 0.0;
+	}
+	t = tic();
+	for ( i = 0; i < iterations; i++ ) {
+		c_dswap_ndarray( len, x, 1, 0, y, 1, 0 );
+		if ( y[ 0 ] != y[ 0 ] ) {
+			printf( "should not return NaN\n" );
+			break;
+		}
+	}
+	elapsed = tic() - t;
+	if ( y[ 0 ] != y[ 0 ] ) {
+		printf( "should not return NaN\n" );
+	}
+	return elapsed;
+}
+
 /**
 * Main execution sequence.
 */
@@ -142,7 +175,14 @@ 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 ( 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 );
 		}

lib/node_modules/@stdlib/blas/base/dswap/examples/c/example.c

@@ -39,4 +39,13 @@ int main( void ) {
 		printf( "x[ %i ] = %lf\n", i, x[ i ] );
 		printf( "y[ %i ] = %lf\n", i, y[ i ] );
 	}
+
+	// Interchange elements:
+	c_dswap_ndarray( N, x, strideX, 0, y, strideY, 6 );
+
+	// Print the result:
+	for ( int i = 0; i < 8; i++ ) {
+		printf( "x[ %i ] = %lf\n", i, x[ i ] );
+		printf( "y[ %i ] = %lf\n", i, y[ i ] );
+	}
 }

lib/node_modules/@stdlib/blas/base/dswap/include/stdlib/blas/base/dswap.h

@@ -36,6 +36,11 @@ extern "C" {
 */
 void API_SUFFIX(c_dswap)( const CBLAS_INT N, double *X, const CBLAS_INT strideX, double *Y, const CBLAS_INT strideY );
 
+/**
+* Interchanges two double-precision floating-point vectors using alternative indexing semantics.
+*/
+void API_SUFFIX(c_dswap_ndarray)( const CBLAS_INT N, double *X, const CBLAS_INT strideX, const CBLAS_INT offsetX, double *Y, const CBLAS_INT strideY, const CBLAS_INT offsetY );
+
 #ifdef __cplusplus
 }
 #endif

lib/node_modules/@stdlib/blas/base/dswap/lib/ndarray.native.js

@@ -20,9 +20,7 @@
 
 // MODULES //
 
-var minViewBufferIndex = require( '@stdlib/strided/base/min-view-buffer-index' );
-var offsetView = require( '@stdlib/strided/base/offset-view' );
-var addon = require( './dswap.native.js' );
+var addon = require( './../src/addon.node' );
 
 
 // MAIN //
@@ -50,16 +48,7 @@ var addon = require( './dswap.native.js' );
 * // y => <Float64Array>[ 1.0, 2.0, 3.0, 4.0, 5.0 ]
 */
 function dswap( N, x, strideX, offsetX, y, strideY, offsetY ) {
-	var viewX;
-	var viewY;
-
-	offsetX = minViewBufferIndex( N, strideX, offsetX );
-	offsetY = minViewBufferIndex( N, strideY, offsetY );
-
-	viewX = offsetView( x, offsetX );
-	viewY = offsetView( y, offsetY );
-
-	addon( N, viewX, strideX, viewY, strideY );
+	addon.ndarray( N, x, strideX, offsetX, y, strideY, offsetY );
 	return y;
 }