% The uniformly distributed random numbers are in the interval (0,1).

X1 = rand;     % retun a singal ramdom number.
X2 = rand(6);     % return a 6-by-6 matrix of random numbers.
X3 = rand(3,4);     % return a 3-by-4 matrix of random numbers.
X4 = -5 + (5+5)*rand(10,1);     % generate a 10-by-1 column vector in (-5,5).

sz = size(X4);     % return the size of the vector X4.