maxk

k largest elements of an array

📝 Syntax

• B = maxk(A, k)

• [B, I] = maxk(A, k)

• B = maxk(A, k, dim)

📥 Input argument

• A - numeric array (vector or matrix)

• k - positive integer specifying how many largest elements to return

• dim - optional dimension along which to operate (default: first non-singleton dimension)

📤 Output argument

• B - array containing the k largest elements of A along the specified dimension

• I - indices of the k largest elements with respect to A along the specified dimension

📄 Description

maxk returns the k largest elements of array A. When A is a vector, the result is the k largest values from A. When A is a matrix, maxk operates along the specified dimension (or the first non-singleton dimension by default) and returns the k largest elements for each slice along that dimension.

If k is larger than the number of available elements along the operating dimension, all elements are returned (sorted descending). When called as [B, I] = maxk(A, k), I contains the indices of the returned elements with respect to A.

💡 Examples

Vector example

A = [5 2 4 1];
B = maxk(A, 2)   % returns [5 4]
[B, I] = maxk(A, 3) % returns [5 4 2] and indices [1 3 2]

Matrix example (along columns)

M = [4 2; 1 3];
B = maxk(M, 1)   % returns [4 3] operating along first non-singleton dimension (columns)
B = maxk(M, 2, 1) % returns 2 largest per column

🔗 See also

mink.

🕔 History

Version	📄 Description
1.15.0	initial version