DSP Blockset

Sort

Sort the elements in the input by value.

Library

Statistics

Description

The Sort block sorts the elements in each column of the input using a Quicksort algorithm. The Mode parameter specifies the block's mode of operation, and can be set to Value, Index, or Value and Index.

Value Mode

When Mode is set to Value, the block sorts the elements in each column of the M-by-N input matrix u in order of ascending or descending value, as specified by the Sort order parameter.

val = sort(u)                % Equivalent MATLAB code (ascending)
val = flipud(sort(u))        % Equivalent MATLAB code (descending)

For convenience, length-M 1-D vector inputs and sample-based length-M row vector inputs are both treated as M-by-1 column vectors.

The output at each sample time, val, is a M-by-N matrix containing the sorted columns of u. Complex inputs are sorted by magnitude, and the output has the same frame status as the input.

Index Mode

When Mode is set to Index, the block sorts the elements in each column of the M-by-N input matrix u,

[val,idx] = sort(u)          % Equivalent MATLAB code (ascending)
[val,idx] = flipud(sort(u))  % Equivalent MATLAB code (descending)

and outputs the sample-based M-by-N index matrix, idx. The jth column of idx is an index vector that permutes the jth column of u to the desired sorting order:

val(:,j) = u(idx(:,j),j)

As in Value mode, length-M 1-D vector inputs and sample-based length-M row vector inputs are both treated as M-by-1 column vectors.

Value and Index Mode

When Mode is set to Value and Index, the block outputs both the sorted matrix, val, and the index matrix, idx.

Dialog Box

Mode

The block's mode of operation: Output the sorted matrix (Value), the index matrix (Index), or both (Value and Index).

Sort order

The order in which to sort the input values, Descending or Ascending. Tunable, except in Simulink's external mode.

See Also

Histogram	DSP Blockset
Median	DSP Blockset
sort	MATLAB

Singular Value Decomposition

Spectrum Scope