Unstack vector into lower triangle of sym.
Syntax:		@unvech(v)
	 v:	vector
Return:		sym
Creates a sym matrix with lower triangle filled using the unstacked elements of the vector v. The sym will be sized automatically. EViews will report a size mismatch if the number of elements of v does not correspond to a valid sym matrix size (is not a triangular number).
Note that @unvech is the inverse of the @vech function. 
Examples
vector v1 = @mnrnd(15)
sym s1 = @unvech(v1)
creates a 15-element vector of normal random numbers V1 and unstacks it into a 

 sym matrix S1.
Cross-references
See also 
    
@unvec, 
    
@vec, and 
    
@vech.