Size input must be scalar error while using rand

I'm trying to run the code:

 k = 2:5;
 A = rand(k, 4);
 disp(rref(A));

It keeps giving me the error "size input must be scalar." I don't know what to change... Thank you in advance.

Answer 1

[Stephen23]

The syntax you use does not work because k is a vector. Taking a wild stab in the dark:

 for k = 2:5
     A = rand(k,4);
     ... your code
 end

[Cassandra Little]

Thank you so much!