what is the difference between matrix and array in the meaning and functions?

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mohammad on 29 Jul 2014

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Commented: Steven Lord on 25 Jun 2022

i want to know the difference between the matrix and array in terms of the meaning and function , if any one will answer please with an example thanks

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dpb on 29 Jul 2014

http://en.wikipedia.org/wiki/Matrix_%28mathematics%29

An array is any ordered n-dimensional collection.

Star Strider on 29 Jul 2014

MATLAB takes liberties with the definition. See for example the documentation on Cell Arrays.

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Answer 1

Arun Mathew Iype on 29 Jul 2014

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Edited: Jan on 30 May 2017

I agree with what dpb said above. Here is the example which will help you visualize.

Matrix

mat_A= [1 2 3; 3 4 5; 6 7 8]

Conventionally this is shown in 2 dimenstions (2D) as:

Mat_A = 
2 3 
4 5 
7 8

Arrays : May be of various dimensions. The above is a 2D array or matrix. A 1D array is called a vector. arr_1D = [1 2 3 4 5 6 7 8 9] We can also have 3D, as well as, ND arrays. In case of a 3D array, imagine a Rubik’s cube with each cell having a value inside it.

Here is and example using MATLAB "rand" function >> Arr_3D = rand(2,2,2)

Arr_3D(:,:,1) =

    0.8147    0.1270
    0.9058    0.9134

Arr_3D(:,:,2) =

    0.6324    0.2785
    0.0975    0.5469

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Markiian on 25 Jun 2022

Thanks a lot!

Steven Lord on 25 Jun 2022

Another way to explain this is by looking at the help text for the ismatrix function.

help ismatrix
 ISMATRIX True if input is a matrix.
    ISMATRIX(M) returns logical 1 (true) if M is an m-by-n matrix, and
    logical 0 (false) otherwise.
 
    See also ISSCALAR, ISVECTOR, ISROW, ISCOLUMN, ISNUMERIC, ISLOGICAL,
             ISCHAR, ISEMPTY, SIZE.

    Documentation for ismatrix
       doc ismatrix

    Other functions named ismatrix

       categorical/ismatrix    distributed/ismatrix    tall/ismatrix
       datetime/ismatrix       duration/ismatrix

So a 1-by-1 array is a matrix. A 3-by-3 array is also a matrix. But a 2-by-3-by-4 array is not a matrix.

ismatrix(zeros(1, 1))
ans = logical
   1
ismatrix(zeros(3, 3))
ans = logical
   1
ismatrix(zeros(2, 3, 4))
ans = logical
   0

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Answer 2

Robin Szeto on 30 May 2017

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All MATLAB variables are multidimensional arrays, no matter what type of data. A matrix is a two-dimensional array often used for linear algebra. source: https://www.mathworks.com/help/matlab/learn_matlab/matrices-and-arrays.html

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Stephen23 on 30 May 2017

Edited: Stephen23 on 30 May 2017

+1 This is true: all MATLAB array types are N-dimensional, with implicit infinite trailing singleton dimensions, as has been discussed many times before:

"Arrays in MATLAB are N-dimensional, with an infinite number of trailing singleton dimensions."

source: http://blogs.mathworks.com/loren/2006/08/09/essence-of-indexing/

https://www.mathworks.com/matlabcentral/answers/21992-singleton-dimention-as-last-dimension-in-matrix

https://www.mathworks.com/matlabcentral/answers/229956-how-can-i-reshape-a-20370x1-matrix-into-2037x10x1

Markee Foster on 9 Apr 2020