Inclusive random numbers on a matrix in matlab

Hi I need to make a 20x10 matrix with random numbers between 0 and 5, inclusive. I already have the matrix but I can't manage to make it inclusive, all the numbers go up tu 4.9999, does anyone know how to do it? I used this formula M=0+(5-0).*rand(20,10)

Answer 1

[Ameer Hamza]

20x10 matrix is too small. rand() generates uniformly distributed random number, and the probability of getting exactly one is significantly less. If you increase the number of the element, you will have a good chance of getting one in rand()

For example

>> M=0+(5-0).*rand(2000,1000); % 2000x1000
>> max(M, [], 'all')
ans =
    5.0000

Checking at higher precision, even this value is less than 5

>> format long
>> max(M, [], 'all')
ans =
   4.999999540115017

Getting excatly 5 is "almost impossible".

If you really want 0 as lower and 5 as upper limit, then you will need to use rescale()

>> M=0+(5-0).*rand(2000,1000); % 2000x1000
>> M = rescale(M, 0, 5);
>> max(M, [], 'all')
ans =
     5
>> min(M, [], 'all')
ans =
     0

[Laura Sofía Macías]

Thank you!

[Ameer Hamza]

I am glad to be of help!

[Andrew M. Soltisz]

Technically, MATLAB's rand() function does not include 0 and 1 (i.e. its range is not inclusive of 0 and 1). So it is literally impossible to randomly sample these numbers from the uniform distribution using MATLAB's built-in function. However, Python's Numpy random.random() method can sample in the range of [0.0, 1.0), so it is inclusive to 0, so there are methods out there to provide inclusive sampling.