Can I use randi and say random number from 1 to 30 except 8 and 9? (for example)

Hi everyone. I have some bad data that I have to exclude from my random index selecter but I can't remove it from my data.

For example, I wanted to say Random integer from 1 to 30, but exclude 8 and 9

This works but when I try to add another integer, like 8 and 9 for example, it doesn't work.

randRow = randi(30,1);
 while randRow == 8
   randRow = randi(30,1);
end

Do you guys know the right syntax? or is there an easier way to do it?

Answer 1

[Stephen]

This is MATLAB, so your first thought should always be to use arrays and indexing:

vec = setdiff(1:30,8:9) % or [1:7,10:30] or whatever

vec = 1×28

1 2 3 4 5 6 7 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

val = vec(randi(numel(vec)))

val = 22

[Akana Juliet]

Thank you @Stephen Cobeldick !!! It's working exactly how I needed it to. Much appreciation

[Stephen]

vec = setdiff(1:30,[8,9,11,15,18])

vec = 1×25

1 2 3 4 5 6 7 10 12 13 14 16 17 19 20 21 22 23 24 25 26 27 28 29 30

How to generate and concatenate vectors is explained here

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

[Akana Juliet]

This is perfect, thanks so much!