MATLAB Function Reference

sort

Sort elements in ascending order

Syntax

• B = sort(A)
  B = sort(A,dim)
  [B,INDEX] = sort(A,...)
  

Description

B = sort(A) sorts the elements along different dimensions of an array, and arranges those elements in ascending order.

If A is a ...	sort(A) ...
Vector	Sorts the elements of A in ascending order.
Matrix	Sorts each column of A in ascending order.
Multidimensional array	Sorts A along the first non-singleton dimension, and returns an array of sorted vectors.
Cell array of strings	Sorts the strings in ASCII dictionary order.

Real, complex, and string elements are permitted. For elements of A with identical values, the order of these elements is preserved in the sorted list. When A is complex, the elements are sorted by magnitude, i.e., abs(A), and where magnitudes are equal, further sorted by phase angle, i.e., angle(A), on the interval . If A includes any NaN elements, sort places these at the end.

B = sort(A,dim) sorts the elements along the dimension of A specified by a scalar dim. If dim is a vector, sort works iteratively on the specified dimensions. Thus, sort(A,[1 2]) is equivalent to sort(sort(A,2),1).

[B,IX] = sort(A,...) also returns an array of indices IX, where size(IX) == size(A). If A is a vector, B = A(IX). If A is an m-by-n matrix, then each column of IX is a permutation vector of the corresponding column of A, such that

• for j = 1:n
      B(:,j) = A(IX(:,j),j); 
  end
  

If A has repeated elements of equal value, the returned indices preserve the original ordering.

Examples

This example sorts a matrix A in each dimension, and then sorts it a third time, requesting an array of indices for the sorted result.

• A = [ 3 7 5
        0 4 2 ];
  
  sort(A,1)
  
  ans =
       0     4     2
       3     7     5
  
  sort(A,2)
  
  ans =
       3     5     7
       0     2     4
  
  [B,IX] = sort(A,2)
  
  B =
       3     5     7
       0     2     4
  
  IX =
       1     3     2
       1     3     2
  

See Also

max, mean, median, min, sortrows

smooth3

sortrows