feat: update JavaScript implementation and add C ndarray implementation for blas/base/scasum

PR-URL: #3068
Ref: #2039
Co-authored-by: Athan Reines <[email protected]>
Reviewed-by: Athan Reines <[email protected]> 
Signed-off-by: Athan Reines <[email protected]>

Author: aman-095

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

@@ -194,6 +194,28 @@ The function accepts the following arguments:
 float c_scasum( const CBLAS_INT N, const void *CX, const CBLAS_INT strideX );
 ```
 
+#### c_scasum_ndarray( N, \*CX, strideX, offsetX )
+
+Computes the sum of the absolute values of the real and imaginary components of a single-precision complex floating-point vector using alternative indexing semantics.
+
+```c
+const float cx[] = { 0.3f, 0.1f, 0.5f, 0.0f, 0.0f, 0.5f, 0.0f, 0.2f };
+
+float out = c_scasum_ndarray( 4, (void *)cx, 1, 0 );
+// returns 1.6f
+```
+
+The function accepts the following arguments:
+
+-   **N**: `[in] CBLAS_INT` number of indexed elements.
+-   **CX**: `[in] void*` input array.
+-   **strideX**: `[in] CBLAS_INT` index increment for `CX`.
+-   **offsetX**: `[in] CBLAS_INT` starting index for `CX`.
+
+```c
+float c_scasum_ndarray( const CBLAS_INT N, const void *CX, const CBLAS_INT strideX, const CBLAS_INT offsetX );  
+```
+
 </section>
 
 <!-- /.usage -->
@@ -231,6 +253,12 @@ int main( void ) {
 
     // Print the result:
     printf( "out: %f\n", out );
+
+    // Compute the sum of the absolute values of real and imaginary components using alternative indexing semantics:
+    out = c_scasum_ndarray( N, (void *)cx, -strideX, N-1 );
+
+    // Print the result:
+    printf( "out: %f\n", out );
 }
 ```
 

lib/node_modules/@stdlib/blas/base/scasum/benchmark/c/benchmark.length.c

@@ -94,7 +94,7 @@ static float rand_float( void ) {
 * @param len          array length
 * @return elapsed time in seconds
 */
-static double benchmark( int iterations, int len ) {
+static double benchmark1( int iterations, int len ) {
 	float cx[ len*2 ];
 	double elapsed;
 	float out;
@@ -121,6 +121,40 @@ 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 ) {
+	float cx[ len*2 ];
+	double elapsed;
+	float out;
+	double t;
+	int i;
+
+	for ( i = 0; i < len*2; i += 2 ) {
+		cx[ i ] = ( rand_float()*10000.0f ) - 5000.0f;
+		cx[ i+1 ] = ( rand_float()*10000.0f ) - 5000.0f;
+	}
+	out = 0.0f;
+	t = tic();
+	for ( i = 0; i < iterations; i++ ) {
+		out = c_scasum_ndarray( len, (void *)cx, 1, 0 );
+		if ( out != out ) {
+			printf( "should not return NaN\n" );
+			break;
+		}
+	}
+	elapsed = tic() - t;
+	if ( out != out ) {
+		printf( "should not return NaN\n" );
+	}
+	return elapsed;
+}
+
 /**
 * Main execution sequence.
 */
@@ -143,7 +177,14 @@ 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/scasum/docs/repl.txt

@@ -9,7 +9,7 @@
     Indexing is relative to the first index. To introduce an offset, use typed
     array views.
 
-    If `N <= 0` or `strideX <= 0`, the function returns `0.0`.
+    If `N <= 0`, the function returns `0.0`.
 
     Parameters
     ----------

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

@@ -34,4 +34,10 @@ int main( void ) {
 
 	// Print the result:
 	printf( "out: %f\n", out );
+
+	// Compute the sum of the absolute values of real and imaginary components using alternative indexing semantics:
+	out = c_scasum_ndarray( N, (void *)cx, -strideX, N-1 );
+
+	// Print the result:
+	printf( "out: %f\n", out );
 }

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

@@ -36,6 +36,11 @@ extern "C" {
 */
 float API_SUFFIX(c_scasum)( const CBLAS_INT N, const void *CX, const CBLAS_INT strideX );
 
+/**
+* Computes the sum of the absolute values of the real and imaginary components of a single-precision complex floating-point vector using alternative indexing semantics.
+*/
+float API_SUFFIX(c_scasum_ndarray)( const CBLAS_INT N, const void *CX, const CBLAS_INT strideX, const CBLAS_INT offsetX );
+
 #ifdef __cplusplus
 }
 #endif

lib/node_modules/@stdlib/blas/base/scasum/lib/ndarray.js

@@ -22,6 +22,7 @@
 
 var absf = require( '@stdlib/math/base/special/absf' );
 var reinterpret = require( '@stdlib/strided/base/reinterpret-complex64' );
+var f32 = require( '@stdlib/number/float64/base/to-float32' );
 
 
 // MAIN //
@@ -31,7 +32,7 @@ var reinterpret = require( '@stdlib/strided/base/reinterpret-complex64' );
 *
 * @param {PositiveInteger} N - number of indexed elements
 * @param {Complex64Array} cx - input array
-* @param {PositiveInteger} strideX - `cx` stride length
+* @param {integer} strideX - `cx` stride length
 * @param {NonNegativeInteger} offsetX - starting index for `cx`
 * @returns {number} result
 *
@@ -51,14 +52,14 @@ function scasum( N, cx, strideX, offsetX ) {
 	var i;
 
 	stemp = 0.0;
-	if ( N <= 0 || strideX <= 0 ) {
+	if ( N <= 0 ) {
 		return stemp;
 	}
 	viewX = reinterpret( cx, 0 );
 	sx = strideX * 2;
 	ix = offsetX * 2;
 	for ( i = 0; i < N; i++ ) {
-		stemp += absf( viewX[ ix ] ) + absf( viewX[ ix+1 ] );
+		stemp = f32( stemp + f32( absf( viewX[ ix ] ) + absf( viewX[ ix+1 ] ) ) );
 		ix += sx;
 	}
 	return stemp;

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

@@ -21,7 +21,6 @@
 // MODULES //
 
 var reinterpret = require( '@stdlib/strided/base/reinterpret-complex64' );
-var minViewBufferIndex = require( '@stdlib/strided/base/min-view-buffer-index' );
 var addon = require( './../src/addon.node' );
 
 
@@ -32,7 +31,7 @@ var addon = require( './../src/addon.node' );
 *
 * @param {PositiveInteger} N - number of indexed elements
 * @param {Complex64Array} cx - input array
-* @param {PositiveInteger} strideX - `cx` stride length
+* @param {integer} strideX - `cx` stride length
 * @param {NonNegativeInteger} offsetX - starting index for `cx`
 * @returns {number} result
 *
@@ -45,10 +44,8 @@ var addon = require( './../src/addon.node' );
 * // returns 14.0
 */
 function scasum( N, cx, strideX, offsetX ) {
-	var viewX;
-	offsetX = minViewBufferIndex( N, strideX, offsetX );
-	viewX = reinterpret( cx, offsetX );
-	return addon( N, viewX, strideX );
+	var viewX = reinterpret( cx, 0 );
+	return addon.ndarray( N, viewX, strideX, offsetX );
 }
 
 

lib/node_modules/@stdlib/blas/base/scasum/lib/scasum.js

@@ -20,6 +20,7 @@
 
 // MODULES //
 
+var stride2offset = require( '@stdlib/strided/base/stride2offset' );
 var ndarray = require( './ndarray.js' );
 
 
@@ -30,7 +31,7 @@ var ndarray = require( './ndarray.js' );
 *
 * @param {PositiveInteger} N - number of indexed elements
 * @param {Complex64Array} cx - input array
-* @param {PositiveInteger} strideX - `cx` stride length
+* @param {integer} strideX - `cx` stride length
 * @returns {number} result
 *
 * @example
@@ -42,7 +43,8 @@ var ndarray = require( './ndarray.js' );
 * // returns 18.0
 */
 function scasum( N, cx, strideX ) {
-	return ndarray( N, cx, strideX, 0 );
+	var ox = stride2offset( N, strideX );
+	return ndarray( N, cx, strideX, ox );
 }
 
 

lib/node_modules/@stdlib/blas/base/scasum/lib/scasum.native.js

@@ -31,7 +31,7 @@ var addon = require( './../src/addon.node' );
 *
 * @param {PositiveInteger} N - number of indexed elements
 * @param {Complex64Array} cx - input array
-* @param {PositiveInteger} strideX - `cx` stride length
+* @param {integer} strideX - `cx` stride length
 * @returns {number} result
 *
 * @example