[R] Converting a asymmetric data frame to symmetric matrix

[K. Taraka Rama]

Hi,

I have a pair-wise distance vector. FOr objects: a,b,c, it is: (a,b) :5, 
(b,c) :6, (a,c) : 7. I want to convert it into a symmetric matrix. I 
used cast function but the function does not fill the matrix like a 
triangular matrix. How do I get a symmetric matrix?

-- 
--Taraka