k permutation of an n-membered vector

"perms" requires a lot of memory for vectors greater than 10 members.If you need limited permutations(k) of a vector, you can use "perms_k".

For use with permutation of 6 and vector with 3 members:

perms_k([700 2 nan],6)

The output is as follows:

ans =

   700   NaN     2
     2   NaN   700
   700     2   NaN
   NaN     2   700
   NaN   700     2
     2   700   NaN 

If you need indexes:

[~ , index] = perms_k([700 2 nan],6)

and output is:

index =

     1     3     2
     1     2     3
     2     3     1
     3     2     1
     2     1     3
     3     1     2

If the amount of permutation required is greater than the factorial of the number of members:

perms_k([700 2 nan],7)

or

[~ , index] = perms_k([700 2 nan],7)

You receive an error with the following content:

# Your chosen k is greater than the number of permutations. 7 is greater of 6.