;+
;FUNCTION:	cb_4d(dat,ENERGY=en,ERANGE=er,EBINS=ebins,ANGLE=an,ARANGE=ar,BINS=bins,MASS=ms,m_int=mi,q=q,mincnt=mincnt)
;INPUT:	
;	dat:	structure,	4d data structure filled by themis routines mvn_sta_c6.pro, mvn_sta_d0.pro, etc.
;KEYWORDS
;	ENERGY:	fltarr(2),	optional, min,max energy range for integration
;	ERANGE:	fltarr(2),	optional, min,max energy bin numbers for integration
;	EBINS:	bytarr(na),	optional, energy bins array for integration
;					0,1=exclude,include,  
;					na = dat.nenergy
;	ANGLE:	fltarr(2,2),	optional, angle range for integration
;				theta min,max (0,0),(1,0) -90<theta<90 
;				phi   min,max (0,1),(1,1)   0<phi<360 
;	ARANGE:	fltarr(2),	optional, min,max angle bin numbers for integration
;	BINS:	bytarr(nb),	optional, angle bins array for integration
;					0,1=exclude,include,  
;					nb = dat.ntheta
;	BINS:	bytarr(na,nb),	optional, energy/angle bins array for integration
;					0,1=exclude,include
;	MASS:	intarr(nm)	optional, 
;PURPOSE:
;	Returns the density array, n, 1/cm^3, corrects for spacecraft potential if dat.sc_pot exists
;NOTES:	
;	Function normally called by "get_3dt" or "get_2dt" to 
;	generate time series data for "tplot.pro".
;
;CREATED BY:
;	J.McFadden	13-11-13	
;LAST MODIFICATION:
;-
function cb_4d,dat2,ENERGY=en,ERANGE=er,EBINS=ebins,ANGLE=an,ARANGE=ar,BINS=bins,MASS=ms,m_int=mi,q=q,mincnt=mincnt

density = 0.

if dat2.valid eq 0 then begin
  print,'Invalid Data'
  return, density
endif

dat = conv_units(dat2,"counts")		; initially use counts
n_e = dat.nenergy
nb = dat.nbins
nm = dat.nmass

data = dat.data 
energy = dat.energy
denergy = dat.denergy
theta = dat.theta/!radeg
phi = dat.phi/!radeg
dtheta = dat.dtheta/!radeg
dphi = dat.dphi/!radeg
domega = dat.domega
	if ndimen(domega) eq 0 then domega=replicate(1.,dat.nenergy)#domega
if n_e eq 64 then nne=8 
if n_e eq 32 then nne=4
if n_e le 16 then nne=2
if n_e eq 48 then nne=6		; when does this happen? is this for swia?
if dat.mode eq 7 then nne=2*nne

if keyword_set(en) then begin
	ind = where(energy lt en[0] or energy gt en[1],count)
	if count ne 0 then data[ind]=0.
endif
if keyword_set(ms) then begin
	ind = where(dat.mass_arr lt ms[0] or dat.mass_arr gt ms[1],count)
	if count ne 0 then data[ind]=0.
endif

; limit the energy range to near the peak
	data2 = data
	if ndimen(data) eq 2 then begin
		maxcnt = max(total(data,2),mind) 
		data[0:(mind-nne>0),*]=0.
		data[((mind+nne)<(n_e-1)):(n_e-1),*]=0.
		en_peak=energy[mind,0]
	endif else begin
		maxcnt = max(data,mind)
		data[0:(mind-nne>0)]=0.
		data[((mind+nne)<(n_e-1)):(n_e-1)]=0.
		en_peak=energy[mind]
	endelse

return, total(data)

end