;+NAME/ONE LINE DESCRIPTION OF ROUTINE:
;    BIN2LL computes the latitude/longitude values for an array of bin numbers.
;


pro ll2bin, nrows,lon,lat,bins

if (n_params() eq 0) then begin
        print, 'bin2ll, nrows,bins,latitude,longitude'
        print, ' '
        print, 'where nrows is the number of records in the BinIndex Vdata'
        print, '      bins is the input array of bin numbers'
        print, '      latitude is the output array of latitude values'
        print, '      longitude is the output array of longitude values'
        return
endif

n = n_elements(lon)

i=indgen(nrows)
latbin=float((i + 0.5) * (180.0d0 / nrows) - 90.0)
numbin=long(cos(latbin *!dpi/180.0) * (2.0*nrows) +0.5)
basebin=lindgen(nrows) & basebin[0]=1
for i=1,nrows-1 do basebin[i]=basebin[i-1] + numbin[i-1]
totbins = basebin[nrows-1] + numbin[nrows-1] - 1
basebin = [basebin, totbins+1]

bins = lonarr(n)
for i=0L,n-1 do begin
    irow = where(latbin ge lat(i)) & irow = irow(0)
    if (irow eq -1) then irow = nrows-1
    icol = (lon(i)+180.)/(360./numbin(irow))
    bins(i) = long(basebin(irow) - 0.5 + icol)
endfor

return
end