Random number selector from double

I have drafted the following code:

num_to_fetch = round(66 / 100 * length(FaY3));
   your_subset = FaY3(randperm(length(FaY3), num_to_fetch));
 your_subsetFas = (your_subset).*(1.46);

where I chose 66% of the data in the double, multiply it by a constant (1.46), then move it into another double. FaY3 actually comes from a 2x43 double defined as FaXY3. What I want to do is modify this code so that whatever 66% of random numbers are selected from FaXY3(2,:), I need the new matrix to also incorporate FaXY3(1,:).

How would I go about doing this?

Answer 1

[Star Strider]

I don’t completely understand what you want with your matrices, but this is one possibility:

D = randi(99, 1 100);                   % Create Data
I = randperm(100,66);                   % Indices (66 Unique Values out of 100)
Out = D(I);                             % Result

I’m not sure what you want to do with your other matrix, but this should get you started.

[jgillis16]

FaXY3 contains both FaY3 and FaX2. Both of FaY3 and FaX2 create coordinates, so if I have 1 in FaY3 it is only associated to 3.5 in FaX2. But, I'm pulling random numbers solely out of FaY3, so I don't have numbers associated with the numbers coming out of FaY3 to FaX2 and so I lose my 'set' created. How would I pull a random number out of FaY3 and the number associated with the place in the matrix out of FaX2 into a new double?

Hope that makes sense...

[Walter Roberson]

Either I do not understand your question or you do not understand Star Strider's answer. If you want corresponding elements of FaY3(1,:) and FaY3(2,:) then use that I index Star Strider shows for both of them.

first_var = FaY3(1,I);
second_var = FaY3(2,I);