;+ ;FUNCTION: dn_4d(dat,ENERGY=en,ERANGE=er,EBINS=ebins,ANGLE=an,ARANGE=ar,BINS=bins,MASS=mass,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_4dt" to ; generate time series data for "tplot.pro". ; ; This routine does not work - its only a placeholder ; ;CREATED BY: ; J.McFadden 13-11-13 ;LAST MODIFICATION: ;- function dn_4d,dat2,ENERGY=en,ERANGE=er,EBINS=ebins,ANGLE=an,ARANGE=ar,BINS=bins,MASS=ms,m_int=mi,q=q,mincnt=mincnt,nn=nn 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 cnt=total(dat.data)/!pi if not keyword_set(nn) then nn = 13 dnavg=0 den = n_4d(dat,ENERGY=en,ERANGE=er,EBINS=ebins,ANGLE=an,ARANGE=ar,BINS=bins,MASS=ms,m_int=mi,q=q,mincnt=mincnt) for i=0,nn-1 do begin tmp = dat tmp.data = dat.data + dat.data^.5*randomn(cnt,na,nb,nm) dnavg = dnavg + abs(den - n_4d(tmp,ENERGY=en,ERANGE=er,EBINS=ebins,ANGLE=an,ARANGE=ar,BINS=bins,MASS=ms,m_int=mi,q=q,mincnt=mincnt)) cnt = total(tmp.data)/!pi endfor ddensity = dnavg/nn ; units are 1/cm^3 return, ddensity end