FUNCTION: swe_n_3d(dat,EBINS=ebins,ABINS=abins,DBINS=dbins) INPUT: dat: structure, 2d data structure filled mvn_swe_get3d KEYWORDS EBINS: bytarr(na), optional, energy bins array for integration 0,1=exclude,include, na = dat.nenergy ABINS: bytarr(16), optional, anode bins array for integration 0,1=exclude,include DBINS: bytarr(6), optional, deflector bins array for integration 0,1=exclude,include OBINS: bytarr(96), optional, solid angle bins for integration 0,1=exclude,include PURPOSE: Returns the density, n, 1/cm^3 CREATED BY: J.McFadden 95-7-27 LAST MODIFICATION: 96-7-6 J.McFadden added more keywords 14-7-6 D.Mitchell redefined keywords, added correction for spacecraft potential