External module "ndarray/base/maybe-broadcast-array/docs/types/index.d"

Export assignment maybeBroadcastArray

• maybeBroadcastArray(arr: ndarray, shape: ArrayLike<number>): ndarray

• Broadcasts an ndarray to a specified shape if and only if the specified shape differs from the provided ndarray's shape.

  Notes

  • The function throws an error if a provided ndarray is incompatible with a provided shape.
  • If a provided ndarray has the same shape as the specified shape, the function returns the provided ndarray.
  • If a provided ndarray has a different (broadcast compatible) shape than the specified shape, the function returns a new (base) ndarray view of the provided ndarray's data. The view is typically not contiguous. As more than one element of a returned view may refer to the same memory location, writing to the view may affect multiple elements. If you need to write to the returned array, copy the array before performing operations which may mutate elements.
  • A returned array view is a "base" ndarray, and, thus, a returned array view does not perform bounds checking or afford any of the guarantees of the non-base ndarray constructor. The primary intent of this function is to broadcast an ndarray-like object within internal implementations and to do so with minimal overhead.

  throws

  input array cannot have more dimensions than the desired shape

  throws

  input array dimension sizes must be 1 or equal to the corresponding dimension in the provided shape

  throws

  input array and desired shape must be broadcast compatible

  Parameters

  • arr: ndarray

    input array

  • shape: ArrayLike<number>

    desired shape

  Returns ndarray

  broadcasted array

  Example

  var array = require( `@stdlib/ndarray/array` );
  
  var x = array( [ [ 1, 2 ], [ 3, 4 ] ] );
  // returns <ndarray>
  
  var shx = x.shape;
  // returns [ 2, 2 ]
  
  var y = maybeBroadcastArray( x, [ 3, 2, 2 ] );
  // returns <ndarray>
  
  var shy = y.shape;
  // returns [ 3, 2, 2 ]
  
  var v = y.get( 0, 0, 0 );
  // returns 1
  
  v = y.get( 0, 0, 1 );
  // returns 2
  
  v = y.get( 1, 0, 0 );
  // returns 1
  
  v = y.get( 1, 1, 0 );
  // returns 3
  
  v = y.get( 2, 0, 0 );
  // returns 1
  
  v = y.get( 2, 1, 1 );
  // returns 4