FUNCTION TRI,X
;+
; FUNCTION TRI,X
; Computes the standard TRI function for any list of values represented
; by the vector x.
;
; USAGE:
; x=FINDGEN(1001)/20-25 CREATE A VECTOR ON THE INTERVAL [-25,25]
; y=TRI((x-8)/5) Construct a function that is shifted and stretched
;
; HISTORY
; Written by Harvey Rhody, May, 2000
;-

RETURN,0.0*X+(X GE -1 AND X LE 0)*(X+1)+ $
	(X GT 0 AND X LE 1)*(1-X)
END