Documentation

numel

Number of array elements

Description

example

n = numel(A) returns the number of elements, n, in array A, equivalent to prod(size(A)).

Examples

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Create a 4-by-4-by-2 matrix.

A = magic(4);
A(:,:,2) = A'
A =
A(:,:,1) =

16     2     3    13
5    11    10     8
9     7     6    12
4    14    15     1

A(:,:,2) =

16     5     9     4
2    11     7    14
3    10     6    15
13     8    12     1

numel counts 32 elements in the matrix.

n = numel(A)
n = 32

Create a string array and compute the number of elements in the array.

A = ["a" "b" "c"; "d" "e" "f"]
A = 2x3 string array
"a"    "b"    "c"
"d"    "e"    "f"

n = numel(A)
n = 6

Create a cell array of character vectors.

A = {'dog','cat','fish','horse'};

numel counts 4 elements in the array.

n = numel(A)
n = 4

Create a table with four variables listing patient information for five people.

LastName = {'Smith';'Johnson';'Williams';'Jones';'Brown'};
Age = [38;43;38;40;49];
Height = [71;69;64;67;64];
Weight = [176;163;131;133;119];
BloodPressure = [124 93; 109 77; 125 83; 117 75; 122 80];

A = table(Age,Height,Weight,BloodPressure,'RowNames',LastName)
A=5×4 table
Age    Height    Weight    BloodPressure
___    ______    ______    _____________

Smith       38       71       176       124     93
Johnson     43       69       163       109     77
Williams    38       64       131       125     83
Jones       40       67       133       117     75
Brown       49       64       119       122     80

Find the number of elements in the table.

n = numel(A)
n = 20

numel returns a value equivalent to prod(size(A)) corresponding to the 5 rows and 4 variables.

Input Arguments

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Input array, specified as a scalar, vector, matrix, multidimensional array, table, or timetable.

Tips

• If A is a table, numel returns the number of elements in the table, A, equivalent to prod(size(A)). Variables in a table can have multiple columns, but numel(A) only accounts for the number of rows and number of variables.

• If A is a character vector of type char, then numel returns the number of characters. However, if A is a string scalar, numel returns 1 because it is a single element of a string array. For example, compare the output of numel for a character vector and string:

nchar = numel('mytext')
nchar =

6
nstr = numel("mytext")
nstr =

1