Geometric mean.
Computes the geometric mean of the elements of 
x for 

Syntax:		@gmean(x[, s])
	x:	 series, vector, matrix
	s:	(optional) sample string or object when x is a series and assigning to a series
Return:		number
The geometric mean is calculated as
For series calculations, EViews will use the current or specified workfile sample.
Examples
If x is a series of length 3 with elements 1, 2, and 4, then
= @gmean(x)
returns 2 (= the cube root of 8).
Cross-references
See also 
    
@mean, 
    
@hmean, and 
    
@trmean.