Generating random number between 1 to 10

Hi everyone,

I want to generate a random number between 1 to 10 for 10 loop iteration, with this code section of mine but i want that each time it generate a different number. Forexample if 2 is generated for the 1st loop iteration, then for the rest of 9 iteration. It won't generate 2 again. Similarly for the rest of other numbers between 1 to 10.

for i=1:10
r = (b-a)*rand(1) + a
end

Answer 1

[dpb]

That's "sampling w/o replacement". One relatively simple way--

N1=1; N2=10;   % range desired
p=randperm(N1:N2);
for i=N1:N2
  r=p(i);
  ...

ERRATA

As noted, in comment, forgot there isn't such a form for randperm. Seems like reasonable enhancement altho it's easy enough to scale externally, too.

Use

N=10;   % range desired
p=randperm(N);
for i=1:N

instead.

[Aftab Ahmed Khan]

Thank you for the response.

but this give me an error of this, Attempted to access p(2); index out of bounds because numel(p)=1.

a=1; 
b=10;   % range desired
p = randperm(a:b);
for i = a:b
  r = p(i);
end

[Aftab Ahmed Khan]

Ok thanks, i solved it.

[dpb]

Ewww...mea culpa. I was thinking there was a vector version of inputs to randperm to move the range from the default 1:N to N1:N2 but there isn't. Was trying to generalize.

For your case, just use

N=10;
p=randperm(N);
for i=1:N
  ...

If you do need integers from other than 1:N, scale the resulting array as needed.

Answer 2

[Jos (10584)]

In matlab you can directly loop over a vector (no need for indexing)

V = randperm(10) % example vector
for x = V
   % x will iterate over the values of V
   disp(x)
end

[Souarv De]

That's nice.

Answer 3

[Juan Gonzalez]

This is the easiest way

ceil(rand*10)

[dpb]

But won't follow the request of OP to have sampling without replacement so that none can be repeated in the 10 samples.

Answer 4

[Elias Gule]

N = 10; % size of the array
numArray = randperm(N); % array containing integers ranging from 1 : N

for k = numArray
   %%perform some calculation/process
   doSomething(k);
end