median() - Signal Processing

M = median(A) returns
the median value of A.If A is a vector, then median(A) returns
the median value of A.If A is a nonempty matrix, then median(A) treats
the columns of A as vectors and returns a row vector
of median values.If A is an empty 0-by-0 matrix, median(A) returns NaN.If A is a multidimensional array,
then median(A) treats the values along the first
array dimension whose size does not equal 1 as
vectors. The size of this dimension becomes 1 while
the sizes of all other dimensions remain the same.median computes natively in the numeric class
of A, such that class(M) = class(A).exampleM = median(A,dim) returns
the median of elements along dimension dim. For
example, if A is a matrix, then median(A,2) is
a column vector containing the median value of each row.exampleM = median(___,nanflag) optionally
specifies whether to include or omit NaN values
in the median calculation for any of the previous syntaxes. For example, median(A,'omitnan') ignores
all NaN values in A.

Syntax

M = median(A) exampleM = median(A,dim) exampleM = median(___,nanflag) example

Example

Median of Matrix ColumnsOpen This Example
Define a 4-by-3 matrix.A = [0 1 1; 2 3 2; 1 3 2; 4 2 2]

A =

     0     1     1
     2     3     2
     1     3     2
     4     2     2

Find the median value of each column.M = median(A)

M =

    1.5000    2.5000    2.0000

For each column, the median value is the mean of the middle two numbers in sorted order.Median of Matrix RowsOpen This Example
Define a 2-by-3 matrix.A = [0 1 1; 2 3 2]

A =

     0     1     1
     2     3     2

Find the median value of each row.M = median(A,2)

M =

     1
     2

For each row, the median value is the middle number in sorted order.Median of 3-D ArrayOpen This Example
Create a 1-by-3-by-4 array of integers between 1 and 10.A = gallery('integerdata',10,[1,3,4],1)

A(:,:,1) =

    10     8    10


A(:,:,2) =

     6     9     5


A(:,:,3) =

     9     6     1


A(:,:,4) =

     4     9     5

Find the median values of this 3-D array along the second dimension.M = median(A)

M(:,:,1) =

    10


M(:,:,2) =

     6


M(:,:,3) =

     6


M(:,:,4) =

     5

This operation produces a 1-by-1-by-4 array by computing the median of the three values along the second dimension. The size of the second dimension is reduced to 1.Compute the median along the first dimension of A.M = median(A,1);
isequal(A,M)

ans =

     1

This command returns the same array as A because the size of the first dimension is 1.Median of 8-Bit Integer ArrayOpen This Example
Define a 1-by-4 vector of 8-bit integers.A = int8(1:4)

A =

    1    2    3    4

Compute the median value.M = median(A),
class(M)

M =

    3


ans =

int8

M is the mean of the middle two numbers in sorted order returned as an 8-bit integer.Median Excluding NaNOpen This ExampleCreate a vector and compute its median, excluding NaN values.A = [1.77 -0.005 3.98 -2.95 NaN 0.34 NaN 0.19];
M = median(A,'omitnan')

M =

    0.2650

Output / Return Value

Limitations

Alternatives / See Also

Reference