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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
Details and Options Details and Options
Examples  
Basic Examples  
Scope  
Generalizations & Extensions  
Applications  
Properties & Relations  
Possible Issues  
See Also
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History
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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:

Wolfram Language code: ArrayReshape[{a, b, c, d, e, f}, {2, 3}]

Reshape a vector into a depth-3 array:

Wolfram Language code: ArrayReshape[Range[24], {2, 3, 4}]

Use a constant padding value:

Wolfram Language code: ArrayReshape[{1, 2, 3, 4, 5, 6, 7}, {5, 3}, x]

Use rule-based padding values:

Wolfram Language code: ArrayReshape[{10, 20, 30, 40, 50, 60, 70}, {5, 3}, "Extrapolated"]

Scope  (1)

Reshape a matrix into another matrix with different dimensions:

Wolfram Language code: ArrayReshape[{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}, {10, 11, 12}}, {3, 4}]

Reshape into a higher rank array:

Wolfram Language code: ArrayReshape[{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}, {10, 11, 12}}, {2, 2, 3}]

Generalizations & Extensions  (1)

ArrayReshape works with SparseArray objects:

Wolfram Language code: ArrayReshape[SparseArray[{1 -> 1, 4 -> 5}, 10], {2, 6}, x]
Wolfram Language code: MatrixForm[%]

Applications  (2)

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

Wolfram Language code: d = ImageData[[image]]; flat = Flatten[d]; ArrayReshape[flat, Dimensions[d]]//Image

Restructure an array:

Wolfram Language code: a = Table[i + j, {i, 4}, {j, 10}]; ArrayReshape[a, {2, 2, 5, 2}]

Properties & Relations  (2)

A function based on Partition equivalent to ArrayReshape without padding:

Wolfram Language code: pareshape[list_, dims_] := Fold[Partition, Flatten[list], dims[[-1 ;; 2 ;; -1]]]
Wolfram Language code: pareshape[Range[24], {2, 3, 4}]
Wolfram Language code: % === ArrayReshape[Range[24], {2, 3, 4}]

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

Wolfram Language code: m = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}};
Wolfram Language code: ArrayReshape[m, Reverse[Dimensions[m]]]
Wolfram Language code: Transpose[m]

Possible Issues  (1)

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

Wolfram Language code: ArrayReshape[Range[100], {2, 3, 4}]
Wolfram Research (2012), ArrayReshape, Wolfram Language function, https://reference.wolfram.com/language/ref/ArrayReshape.html.

Text

Wolfram Research (2012), ArrayReshape, Wolfram Language function, https://reference.wolfram.com/language/ref/ArrayReshape.html.

CMS

Wolfram Language. 2012. "ArrayReshape." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/ArrayReshape.html.

APA

Wolfram Language. (2012). ArrayReshape. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/ArrayReshape.html

BibTeX

@misc{reference.wolfram_2026_arrayreshape, author="Wolfram Research", title="{ArrayReshape}", year="2012", howpublished="\url{https://reference.wolfram.com/language/ref/ArrayReshape.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_arrayreshape, organization={Wolfram Research}, title={ArrayReshape}, year={2012}, url={https://reference.wolfram.com/language/ref/ArrayReshape.html}, note=[Accessed: 12-June-2026]}