Gamma mean and variance
[M,V] = gamstat(A,B)
[M,V] = gamstat(A,B) returns the mean of and variance for the gamma distribution with shape parameters in A and scale parameters in B. A and B can be vectors, matrices, or multidimensional arrays that have the same size, which is also the size of M and V. A scalar input for A or B is expanded to a constant array with the same dimensions as the other input.
The mean of the gamma distribution with parameters a and b is ab. The variance is ab2.
[m,v] = gamstat(1:5,1:5) m = 1 4 9 16 25 v = 1 8 27 64 125 [m,v] = gamstat(1:5,1./(1:5)) m = 1 1 1 1 1 v = 1.0000 0.5000 0.3333 0.2500 0.2000