pickn

Return P random picks of N items from an input vector A.

Description

B = PICKN(A,N,P)

Returns P random Picks of N items from vector A.

PickN assumes that each item can be repelaced after selection.

Example:
  A list contains four elements: [1 2 3 4]
  Show two possible combinations of choosing 3 items
  from the list.

A = [1:4];
N = 3;
P = 2;

B = pickn(A,N,P)

      1 3 1
      2 4 1

If you specifcy P as the string 'all', then B will contain
all possible permutations.

• MATLAB release: MATLAB 6.5 (R13)

[Matthias Wetzel]

 

[Jos x@y.z]

B = A(ceil(numel(A)*rand(P,N))) ;
would do the job much (much!!) faster.
Creating all possible combinations first is very time- and memory consuming ... The retrieval of all combinations of elements is handled much more efficient by other contributions here (search the FEX for "combinations")

[Richard Medlock]

Hi, thanks for your feedback. This file was written well over 4 years ago (before you reviewed it) and at the time there was nothing available that did this. As with all my files they were simple (in my mind) solutions to achieve what I wanted and worked. I posted them in case anyone else found them useful. Perhaps you might consider that in future when rating (very!!) old submissions ;-)