Beginner coding; my second, simpler approach at trying to make all elements distinct.

So this is what I've come up with on my own to print a 3x3 random matrix of integers only; no element value exceeding n^2 (9 in this case). I think I've done that correctly, it seems to be working. Keep in mind I've just started learning.

what can I add to ensure that every element will be unique, i.e for this case, all numbers 1-9 should be represented ONCE in the 3x3 matrix; none repeating. As you can see from what I've pasted from the command window, there are two 8's!

If you're willing please explain the thought behind it and exactly how I should approach modifying what's existing. Thanks!

Script

___________

n=3

q=(n^2)*rand(n)

ceil(q)

__________

OUTPUT:

n =

3

q =

7.3798 4.7820 5.4986

6.4652 2.9263 7.0092

8.7178 0.9507 3.8111

ans =

8 5 6

7 3 8

9 1 4

Answer 1

[James Tursa]

FYI, to generate random integers you can use the randi( ) function instead of ceil(value*rand( )):

https://www.mathworks.com/help/matlab/ref/randi.html?searchHighlight=randi&s_tid=srchtitle_randi_1

To get unique integers you can use the randperm( ) function. E.g.,

randperm(n^2)

https://www.mathworks.com/help/matlab/ref/randperm.html?searchHighlight=randperm&s_tid=srchtitle_randperm_1

That will get you a vector. To get a matrix simply reshape the result:

reshape(randperm(n^2),n,n)

https://www.mathworks.com/help/matlab/ref/reshape.html?searchHighlight=reshape&s_tid=srchtitle_reshape_1