Permute a grouped vector

(Extension of RANDPERM)

Description

Function RANDPERG extends Matlab's RANDPERM by considering permutations of a grouped vector: if x is an n*1 data vector, and c is an n*1 vector of group assignments - so that x(i) belongs to group c(i) - randperg(x,c) returns an n*1 vector y where each c group retains the indexes it had in x [permutation is thus 'partial'], but its individual elements are randomly rearranged. See the function's help header for details.

Acknowledgements

The author wishes to acknowledge the following in the creation of this submission:
PARTPERM -- Partial random permutation of a vector, SHAKE

• MATLAB release: MATLAB 7.0.1 (R14SP1)