function WSIGN, num
;+
;NAME:
;	WSIGN
;PURPOSE:
;	To compute the sign of a number. This function mimics
;	Matlab's sign function.
;
;CALLING SEQUENCE:
;	Result = WSIGN(num)
;INPUTS:
;	Num:	Any number or array
;
;OUTPUTS:
;	WSIGN returns either 1, 0, or -1.
;		
;	None.
;MODIFICATION HISTORY:
;	Amara Graps, BAER, December 1994.
;	(c) copyright Amara Graps 1995, 1996.
;-

t = SIZE(num)
testtype = t(0)

IF testtype NE 0 THEN BEGIN
	;The value num is an array.. Find the sign of ALL of the elements
	;create same size and kind of array
	n_ele = N_ELEMENTS(t)
	CASE t(n_ele-2) OF
		2: sgn = num * 0	;integer
		3: sgn = num * 0L	;long integer
		4: sgn = num * 0.0	;floating
		5: sgn = num * 0.0D0	;double floating
		ELSE: print, 'Not a good array type in WSIGN!'
	ENDCASE
	copy_num= num
	
	;neg values
	indx = WHERE(copy_num LT 0)	
	;check for bad index
	ts = SIZE(indx)
	CASE 1 OF
		(ts(0) EQ 0): ;no change
		ELSE: sgn(indx) = -1
	ENDCASE

	;positive values
	indx = WHERE(copy_num GT 0)	
	;check for bad index
	ts = SIZE(indx)
	CASE 1 OF
		(ts(0) EQ 0): ;no change
		ELSE: sgn(indx) = +1
	ENDCASE

	;zero values
	indx = WHERE(copy_num EQ 0)	
	;check for bad index
	ts = SIZE(indx)
	CASE 1 OF
		(ts(0) EQ 0): ;no change
		ELSE: sgn(indx) = 0
	ENDCASE
	
	
ENDIF ELSE BEGIN

	;t(0) = 0, scalar.. what we want
	
	IF t(1) NE 6L then begin
		;Not a complex scalar
		
		CASE 1 OF
			num LT 0: sgn = -1
			num EQ 0: sgn = 0          
			num GT 0: sgn = 1
			ELSE: print, 'Not a valid number!'
		ENDCASE
	ENDIF ELSE BEGIN
		;This is a complex scalar
		sgn = num / abs(num)
	END	;END
END

RETURN, sgn

END