ArrayReshape

ArrayReshape[list,dims]

arranges the elements of list into a rectangular array with dimensions dims.

ArrayReshape[list,dims,padding]

uses the specified padding if list does not contain enough elements.

Details

  • ArrayReshape always gives a rectangular array of the specified dimensions, ignoring the last elements or adding new elements as necessary.
  • Elements are arranged in the resulting array so that up to length, Flatten[ArrayReshape[list,dims]] is the same as Flatten[list].
  • In ArrayReshape[list,dims,padding], any padding scheme supported by ArrayPad can be specified. The default padding value is 0.
  • ArrayReshape works with SparseArray objects.

Examples

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Basic Examples  (4)

Create a 2×3 matrix:

Reshape a vector into a depth-3 array:

Use a constant padding value:

Use rule-based padding values:

Scope  (1)

Reshape a matrix into another matrix with different dimensions:

Reshape into a higher rank array:

Generalizations & Extensions  (1)

ArrayReshape works with SparseArray objects:

Applications  (2)

Create an image from a flat list of channel values, effectively inverting the process of flattening image data:

Restructure an array:

Properties & Relations  (2)

A function based on Partition equivalent to ArrayReshape without padding:

Reversing matrix dimensions does not give the same element order as Transpose:

Possible Issues  (1)

Elements from the original list that do not fit in the given dimensions are dropped:

Introduced in 2012
 (9.0)