;+
;FUNCTION: c_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 c_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
na = 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
mass = dat.mass*dat.mass_arr
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
return, total(data)
end