Matlab - Media elementos positivos de una matriz en matlab

>> A=-round(5*rand(4,5))

A =

    -4     0    -3    -4    -3

    -2    -1     0     0    -4

    -1    -5    -1     0    -3

    -2    -5    -2    -1    -2

>> B=round(2*rand(4,5)+1)

B =

     2     2     3     2     2

     2     1     1     2     2

     2     2     3     2     3

     1     2     3     2     3

>> C=A.^B

C =

    16     0   -27    16     9

     4    -1     0     0    16

     1    25    -1     0   -27

    -2    25    -8     1    -8

>> T=C(C>0)

T =

    16

     4

     1

    25

    25

    16

     1

     9

    16

>> R=mean(T)

R =

   12.5556