;+
;FUNCTION: wc_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
;PURPOSE:
; Returns the anisotropy
;NOTES:
; Function normally called by "get_4dt" to
; generate time series data for "tplot.pro".
;
;CREATED BY:
; J.McFadden 14-02-26
;LAST MODIFICATION:
;-
function wc_4d,dat2,ENERGY=en,ERANGE=er,EBINS=ebins,ANGLE=an,ARANGE=ar,BINS=bins,MASS=ms,m_int=mi,q=q,mincnt=mincnt
iso = 0
if dat2.valid eq 0 then begin
print,'Invalid Data'
return, iso
endif
if dat2.nbins eq 1 then return,iso
dat = conv_units(dat2,"counts") ; initially use counts
data = dat.data
energy = dat.energy
theta = dat.theta/!radeg
phi = dat.phi/!radeg
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
if keyword_set(mincnt) then if total(data) lt mincnt then return,0
dat.data=data
dat = conv_units(dat2,"eflux") ; Use energy flux
data=dat.data
if dat.nmass gt 1 then an_arr = total(total(data,3),1) else an_arr = total(data,1)
max_an = max(an_arr,ind)
iso = 1. - total(an_arr)/(an_arr[ind]*dat.nbins+1.e-20)
return,iso ; anisotropy
end