y=lscov(A,b,V)
Inputs  
A 
Any real matrix. 
b 
A vector with the same number of rows as A . 
V 
A positive definite matrix whose size is the same as the number of rows in A .

Outputs  
y 
The weighted least square solution of A*x=b as described below. 
norm(inv(B)(A*xb),2)
where
B
is related to the input via V=B*B'
.