;+
; NAME:
;	fMaxLoc
; PURPOSE: (one line)
;	Returns the location of the maximum in a 1-D array
; DESCRIPTION:
;	This function returns finds the maximum point in a 1-D array, then fits
;	a parabola to the maximum and its left and right neighbors. The center of
;	the parabola is assumed to be the fractional location of the maximum. 
;	NOTICE that this function is useless if the FWHM is small compared to a pixel.
; CATEGORY:
;	Spectral extraction
; CALLING SEQUENCE:
;	fMax = fMaxLoc(v)
; INPUTS:
;	myVec	- Input 1-D array.
; OPTIONAL INPUT PARAMETERS:
; KEYWORD PARAMETERS:
; OUTPUTS:
;	fMax	- the location of the maximum
; COMMON BLOCKS:
; SIDE EFFECTS:
; RESTRICTIONS:
; PROCEDURE:
; MODIFICATION HISTORY:
;	Written June 6, 1996, Eliot Young, NASA Ames Research Center
;	Modified June 22, 1999, Jason Cook & Leslie Young, BU.
;		Found y1=0, y3=0, and arrWidth bugs.
;	Modified Dec 21, 1999, Leslie Young, SwRI.
;		Found bracketing bug
;-
function fMaxLoc,v
	
	sz = size(v)
	arrLen = sz(1)
	arrWidth = sz(2)
	
	xVals = findgen(3)
	yVals = fltarr(3)
	xVals = xVals - 1.0	;Should be [-1., 0., 1.]
	
	maxVal = max(v, imax)

;	for i = 0,2 do begin &$
;	yVals(i) = v((arrLen + imax + xVals(i)) MOD arrLen) &$
;	endfor

;	if imax-1 lt 0 then y1=0
	if imax-1 lt 0 then begin &$
	   Beforeimax=((arrLen + imax - 1) MOD arrLen) &$
	   y1=v(Beforeimax) &$
	endif

	if imax-1 ge 0 then begin &$
	y1=v(imax-1) &$
	endif 

	y2=v(imax)

;	if imax+1 gt arrWidth-1 then y3=0
	if imax+1 gt arrLen-1 then begin &$
	   Afterimax=((arrLen + imax + 1) MOD arrLen) &$
	   y3=v(Afterimax) &$
	endif


;	if imax+1 le arrWidth-1 then begin &$
	if imax+1 le arrLen-1 then begin &$
	y3=v(imax+1) &$
	endif

;	x=-[(y3-y1)/2]/(y1+y3-2*y2)
	x=-((y3-y1)/2.)/(y1+y3-2.*y2)  ; LAY 1999

;	coefs = poly_fit(xVals, yVals, 2, n)
;	fMax = -0.5 * coefs(1)/coefs(2) + imax

	fmax=x+imax

;	print, "fmaxloc happened", y1, y2, y3
	return,fMax
end