I am trying to randomly disperse different numbers in MATLAB array:

I am trying to randomly disperse different numbers in MATLAB array:

I have two 3's, four 2's and I want to randomly populate ones vector (size 10,1).

End Result look something like this:

A = [1; 3; 1; 2; 3; 2; 2; 1; 1; 2; 1; 1]

Then I want to fix the values in A but add more random elements but I can only replace with higher numbers:

for example, to the matrix above I will randomly add two more 2's and two more 3's giving something like this

A2 =[ 3; 3; 2; 2; 3; 2; 2; 2; 1; 2; 1; 3]

[Jos (10584)]

Two questions:

1. Is it also allowed to replace 2's but 3's, or can only 1's change into higher number?
2. Do you specify how many new 2's or 3's have to appear, or do you only set the total number of changes?

[Keith]

Jos,

only 1's and 2's can change. 3 is the max number. I will fix the total number of changes myself.

Thanks

Answer 1

[Jos (10584)]

V = ones(1,10)
V(1:4) = 2 
V(5:6) = 3

V = V(randperm(numel(V))) % randomize the order initially

% change four 1's into two 2's and two 3's
idx = find(V==1) % where are the 1's
idx = idx(randperm(numel(idx)))
V(idx(1:4)) = [2 2 3 3]

[Keith]

Very nice, thank you.