npm package: @stdlib/ndarray-base-flatten-shape-from
Description: Flatten a shape starting from a specified dimension.
Author: The Stdlib Authors
Latest version: 0.1.1

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# flattenShapeFrom

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> Flatten a shape starting from a specified dimension.

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<section class="intro">

</section>

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<!-- Package usage documentation. -->

<section class="installation">

## Installation

```bash
npm install @stdlib/ndarray-base-flatten-shape-from
```

</section>

<section class="usage">

## Usage

```javascript
var flattenShapeFrom = require( '@stdlib/ndarray-base-flatten-shape-from' );
```

#### flattenShapeFrom( shape, dim )

Flattens a shape starting from a specified dimension.

```javascript
var sh = flattenShapeFrom( [ 3, 3, 2 ], 1 );
// returns [ 3, 6 ]
```

The function accepts the following parameters:

-   **shape**: array shape.
-   **dim**: dimension to start flattening from.

#### flattenShapeFrom.assign( shape, dim, out )

Flattens a shape starting from a specified dimension and assigns results to a provided output array.

```javascript
var sh = [ 0, 0 ];

var out = flattenShapeFrom.assign( [ 3, 3, 2 ], 1, sh );
// returns [ 3, 6 ]

var bool = ( sh === out );
// returns true
```

The function accepts the following parameters:

-   **shape**: array shape.
-   **dim**: dimension to start flattening from. If provided an integer less than zero, the dimension index is resolved relative to the last dimension, with the last dimension corresponding to the value `-1`.
-   **out**: output array.

</section>

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</section>

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<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var discreteUniform = require( '@stdlib/random-array-discrete-uniform' );
var zip = require( '@stdlib/array-base-zip' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var flattenShapeFrom = require( '@stdlib/ndarray-base-flatten-shape-from' );

var opts = {
    'dtype': 'int32'
};
var d1 = discreteUniform( 100, 1, 10, opts );
var d2 = discreteUniform( d1.length, 1, 10, opts );
var d3 = discreteUniform( d1.length, 1, 10, opts );
var d4 = discreteUniform( d1.length, 1, 10, opts );

var dims = discreteUniform( d1.length, -4, 3, opts );
var shapes = zip( [ d1, d2, d3, d4 ] );

logEachMap( 'shape: (%s). dim: %d. flattened: (%s).', shapes, dims, flattenShapeFrom );
```

</section>

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* * *

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## C APIs

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<section class="usage">

### Usage

```c
#include "stdlib/ndarray/base/flatten_shape_from.h"
```

#### stdlib_ndarray_flatten_shape_from( ndims, \*shape, dim, \*out )

Flattens a shape starting from a specified dimension.

```c
const int64_t ndims = 3;
const int64_t shape[] = { 2, 3, 10 };
int64_t out[ 2 ];

stdlib_ndarray_flatten_shape( ndims, shape, 1, out );
```

The function accepts the following arguments:

-   **ndims**: `[in] int64_t` number of dimensions.
-   **shape**: `[in] int64_t*` array shape (dimensions).
-   **dim**: `[in] int64_t` dimension to start flattening from.
-   **out**: `[out] int64_t*` output array.

```c
int8_t stdlib_ndarray_flatten_shape_from( const int64_t ndims, const int64_t *shape, const int64_t dim, int64_t *out );
```

</section>

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</section>

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<section class="examples">

### Examples

```c
#include "stdlib/ndarray/base/flatten_shape_from.h"
#include <stdio.h>
#include <inttypes.h>

int main( void ) {
    const int64_t shape[] = { 2, 3, 4, 10 };
    const int64_t ndims = 4;
    const int64_t dim = 2;
    int64_t out[ 3 ];

    stdlib_ndarray_flatten_shape_from( ndims, shape, dim, out );

    int i;
    printf( "shape = ( " );
    for ( i = 0; i < ndims-dim+1; i++ ) {
        printf( "%"PRId64"", out[ i ] );
        if ( i < ndims-dim ) {
            printf( ", " );
        }
    }
    printf( " )\n" );
}
```

</section>

<!-- /.examples -->

</section>

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* * *

## Notice

This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].

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## License

See [LICENSE][stdlib-license].


## Copyright

Copyright &copy; 2016-2026. The Stdlib [Authors][stdlib-authors].

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