Skip to content
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
135 changes: 125 additions & 10 deletions lib/node_modules/@stdlib/blas/ext/base/ssumpw/README.md
Original file line number Diff line number Diff line change
Expand Up @@ -36,27 +36,26 @@ limitations under the License.
var ssumpw = require( '@stdlib/blas/ext/base/ssumpw' );
```

#### ssumpw( N, x, stride )
#### ssumpw( N, x, strideX )

Computes the sum of single-precision floating-point strided array elements using pairwise summation.

```javascript
var Float32Array = require( '@stdlib/array/float32' );

var x = new Float32Array( [ 1.0, -2.0, 2.0 ] );
var N = x.length;

var v = ssumpw( N, x, 1 );
var v = ssumpw( x.length, x, 1 );
// returns 1.0
```

The function has the following parameters:

- **N**: number of indexed elements.
- **x**: input [`Float32Array`][@stdlib/array/float32].
- **stride**: index increment for `x`.
- **strideX**: stride length for `x`.

The `N` and stride parameters determine which elements in the strided array are accessed at runtime. For example, to compute the sum of every other element in `x`,
The `N` and stride parameters determine which elements in the strided array are accessed at runtime. For example, to compute the sum of every other element:

```javascript
var Float32Array = require( '@stdlib/array/float32' );
Expand All @@ -81,25 +80,24 @@ var v = ssumpw( 4, x1, 2 );
// returns 5.0
```

#### ssumpw.ndarray( N, x, stride, offset )
#### ssumpw.ndarray( N, x, strideX, offsetX )

Computes the sum of single-precision floating-point strided array elements using pairwise summation and alternative indexing semantics.

```javascript
var Float32Array = require( '@stdlib/array/float32' );

var x = new Float32Array( [ 1.0, -2.0, 2.0 ] );
var N = x.length;

var v = ssumpw.ndarray( N, x, 1, 0 );
var v = ssumpw.ndarray( x.length, x, 1, 0 );
// returns 1.0
```

The function has the following additional parameters:

- **offset**: starting index for `x`.
- **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 calculate the sum of every other value in `x` starting from the second value
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 calculate the sum of every other element starting from the second element:

```javascript
var Float32Array = require( '@stdlib/array/float32' );
Expand Down Expand Up @@ -147,6 +145,123 @@ console.log( v );

<!-- /.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/ssumpw.h"
```

#### stdlib_strided_ssumpw( N, \*X, strideX )

Computes the sum of single-precision floating-point strided array elements using pairwise summation.

```c
const float x[] = { 1.0f, -2.0f, 2.0f };

double v = stdlib_strided_ssumpw( 3, x, 1 );
// returns 1.0
```

The function accepts the following arguments:

- **N**: `[in] CBLAS_INT` number of indexed elements.
- **X**: `[in] float*` input array.
- **strideX**: `[in] CBLAS_INT` stride length for `X`.

```c
double stdlib_strided_ssumpw( const CBLAS_INT N, const float *X, const CBLAS_INT strideX );
```

#### stdlib_strided_ssumpw_ndarray( N, \*X, strideX, offsetX )

Computes the sum of single-precision floating-point strided array elements using pairwise summation and alternative indexing semantics.

```c
const float x[] = { 1.0f, -2.0f, 2.0f };

double v = stdlib_strided_ssumpw_ndarray( 3, x, 1, 0 );
// returns 1.0
```

The function accepts the following arguments:

- **N**: `[in] CBLAS_INT` number of indexed elements.
- **X**: `[in] float*` input array.
- **strideX**: `[in] CBLAS_INT` stride length for `X`.
- **offsetX**: `[in] CBLAS_INT` starting index for `X`.

```c
double stdlib_strided_ssumpw_ndarray( const CBLAS_INT N, const float *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/ssumpw.h"
#include <stdio.h>

int main( void ) {
// Create a strided array:
const float x[] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f };

// Specify the number of elements:
const int N = 4;

// Specify the stride length:
const int strideX = 2;

// Compute the sum:
float v = stdlib_strided_ssumpw( N, x, strideX );

// Print the result:
printf( "sum: %f\n", v );
}
```

</section>

<!-- /.examples -->

</section>

<!-- /.c -->

* * *

<section class="references">
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -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 ) {
double elapsed;
float x[ len ];
float v;
Expand All @@ -107,6 +107,7 @@ static double benchmark( int iterations, int len ) {
v = 0.0f;
t = tic();
for ( i = 0; i < iterations; i++ ) {
// cppcheck-suppress uninitvar
v = stdlib_strided_ssumpw( len, x, 1 );
if ( v != v ) {
printf( "should not return NaN\n" );
Expand All @@ -120,6 +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 ) {
double elapsed;
float x[ len ];
double v;
double t;
int i;

for ( i = 0; i < len; i++ ) {
x[ i ] = ( rand_float()*20000.0f ) - 10000.0f;
}
v = 0.0f;
t = tic();
for ( i = 0; i < iterations; i++ ) {
// cppcheck-suppress uninitvar
v = stdlib_strided_ssumpw_ndarray( len, x, 1, 0 );
if ( v != v ) {
printf( "should not return NaN\n" );
break;
}
}
elapsed = tic() - t;
if ( v != v ) {
printf( "should not return NaN\n" );
}
return elapsed;
}

/**
* Main execution sequence.
*/
Expand All @@ -142,7 +177,18 @@ 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 );
}
Expand Down
22 changes: 11 additions & 11 deletions lib/node_modules/@stdlib/blas/ext/base/ssumpw/docs/repl.txt
Original file line number Diff line number Diff line change
@@ -1,10 +1,10 @@

{{alias}}( N, x, stride )
{{alias}}( N, x, strideX )
Computes the sum of single-precision floating-point strided array elements
using pairwise summation.

The `N` and `stride` parameters determine which elements in the strided
array are accessed at runtime.
The `N` and stride parameters determine which elements in the strided array
are accessed at runtime.

Indexing is relative to the first index. To introduce an offset, use a typed
array view.
Expand All @@ -19,8 +19,8 @@
x: Float32Array
Input array.

stride: integer
Index increment.
strideX: integer
Stride length.

Returns
-------
Expand All @@ -34,7 +34,7 @@
> {{alias}}( x.length, x, 1 )
1.0

// Using `N` and `stride` parameters:
// Using `N` and stride parameters:
> x = new {{alias:@stdlib/array/float32}}( [ -2.0, 1.0, 1.0, -5.0, 2.0, -1.0 ] );
> {{alias}}( 3, x, 2 )
1.0
Expand All @@ -46,12 +46,12 @@
-1.0


{{alias}}.ndarray( N, x, stride, offset )
{{alias}}.ndarray( N, x, strideX, offsetX )
Computes the sum of single-precision floating-point strided array elements
using pairwise summation and alternative indexing semantics.

While typed array views mandate a view offset based on the underlying
buffer, the `offset` parameter supports indexing semantics based on a
buffer, the offset parameter supports indexing semantics based on a
starting index.

Parameters
Expand All @@ -62,10 +62,10 @@
x: Float32Array
Input array.

stride: integer
Index increment.
strideX: integer
Stride length.

offset: integer
offsetX: integer
Starting index.

Returns
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -27,7 +27,7 @@ interface Routine {
*
* @param N - number of indexed elements
* @param x - input array
* @param stride - stride length
* @param strideX - stride length
* @returns sum
*
* @example
Expand All @@ -38,15 +38,15 @@ interface Routine {
* var v = ssumpw( x.length, x, 1 );
* // returns 1.0
*/
( N: number, x: Float32Array, stride: number ): number;
( N: number, x: Float32Array, strideX: number ): number;

/**
* Computes the sum of single-precision floating-point strided array elements using pairwise summation and alternative indexing semantics.
*
* @param N - number of indexed elements
* @param x - input array
* @param stride - stride length
* @param offset - starting index
* @param strideX - stride length
* @param offsetX - starting index
* @returns sum
*
* @example
Expand All @@ -57,15 +57,15 @@ interface Routine {
* var v = ssumpw.ndarray( x.length, x, 1, 0 );
* // returns 1.0
*/
ndarray( N: number, x: Float32Array, stride: number, offset: number ): number;
ndarray( N: number, x: Float32Array, strideX: number, offsetX: number ): number;
}

/**
* Computes the sum of single-precision floating-point strided array elements using pairwise summation.
*
* @param N - number of indexed elements
* @param x - input array
* @param stride - stride length
* @param strideX - stride length
* @returns sum
*
* @example
Expand Down
Original file line number Diff line number Diff line change
Expand Up @@ -17,21 +17,20 @@
*/

#include "stdlib/blas/ext/base/ssumpw.h"
#include <stdint.h>
#include <stdio.h>

int main( void ) {
// Create a strided array:
const float x[] = { 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 };
const float x[] = { 1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f };

// Specify the number of elements:
const int64_t N = 4;
const int N = 4;

// Specify the stride length:
const int64_t stride = 2;
const int strideX = 2;

// Compute the sum:
float v = stdlib_strided_ssumpw( N, x, stride );
float v = stdlib_strided_ssumpw( N, x, strideX );

// Print the result:
printf( "sum: %f\n", v );
Expand Down
Loading