ismatrix - Determine whether input is matrix - MATLAB (original) (raw)
Main Content
Determine whether input is matrix
Syntax
Description
TF = ismatrix([A](#mw%5F65841dfa-f32c-438c-a843-31feb1519019)) returns logical1 (true) if A is a matrix. Otherwise, it returns logical 0 (false). A matrix is a two-dimensional array that has a size of m_-by-n, where_m and n are nonnegative integers.
Examples
Determine whether arrays of different sizes are matrices.
Create an array of size 1-by-3. Determine whether it is a matrix.
A1 = zeros(1,3); TF = ismatrix(A1)
Create an empty array of size 0-by-3. Determine whether it is a matrix. A 2-D empty array is a matrix.
A2 = zeros(0,3); TF = ismatrix(A2)
Create an array of size 1-by-3-by-2. Determine whether it is a matrix. A 3-D array is not a matrix.
A3 = zeros(1,3,2); TF = ismatrix(A3)
Create a 3-D array and determine whether the array elements are a matrix.
First define a 2-D array of size 2-by-3. Determine whether it is a matrix.
A = [0.1 0.2 0.5; 0.3 0.6 0.4]
A = 2×3
0.1000 0.2000 0.5000
0.3000 0.6000 0.4000To create a 3-D array, add a third dimension to the array A. Assign another 2-by-3 matrix to the third dimension of A with index value 2.
A = A(:,:,1) =
0.1000 0.2000 0.5000
0.3000 0.6000 0.4000A(:,:,2) =
1 1 1
1 1 1Check whether the 3-D array of size 2-by-3-by-2 is a matrix.
Now determine whether the array elements of A are a matrix. Check whether the second page of the 3-D array is a matrix. The syntax A(:,:,2) uses a colon in the first and second dimensions to access all rows and all columns.
Check whether the second row of the 3-D array is a matrix. The syntax A(2,:,:) uses a colon in the second and third dimensions to include all columns and all pages.
A(:,:,2) is a matrix since it is a multidimensional array of size 2-by-3. However, A(2,:,:) is not a matrix since it is a multidimensional array of size 1-by-3-by-2.
Create an array of characters. Determine whether it is a matrix.
A = 'Hello, World!'; TF = ismatrix(A)
Check the dimension of A using size. A is a matrix of size 1-by-13.
Now create a string scalar by enclosing a piece of text in double quotes.
Check whether the scalar A of size 1-by-1 is also a matrix.
Input Arguments
Input array, specified as a scalar, vector, matrix, or multidimensional array.
Extended Capabilities
Theismatrix function fully supports tall arrays. For more information, see Tall Arrays.
The ismatrix function fully supports GPU arrays. To run the function on a GPU, specify the input data as a gpuArray (Parallel Computing Toolbox). For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).
Version History
Introduced in R2010b