Re: Help setting up an array

[Mark Fardal <fardal(at)weka.astro.umass.edu>]

> Now, what I want to be able to do is re-bin these points into an
> n-dimensional discretized space array which encloses all points. I can

You mean something like this?  I'm sure there are many ways to do it.

pro thorne, x, w, box
;x[ndim, npts]
;w[npts]

npts = n_elements(x[0,*])
ndim = n_elements(x[*,0])

xmin = fltarr(ndim)
xmax = fltarr(ndim)
dx = fltarr(ndim)
for i = 0, ndim-1 do begin
   xmin[i] = min(x[i,*])
   xmax[i] = max(x[i,*])
endfor
dx[*] = 1.  ;how is this determined?
ngrid = ceil( (xmax - xmin) / dx + 1.e-4 )

ibox = lonarr(npts)
nmult = 1
for i = 0, ndim-1 do begin
   ibox = ibox + nmult * fix( ( x[i,*] - xmin[i] ) / dx[i] )
   nmult = nmult * ngrid[i]
endfor

;this could be improved with histogram?
box = fltarr(nmult)
for j = 0, npts-1 do begin
   box[ibox[j]] = box[ibox[j]] + w[j]
endfor

string = 'box = reform(box, ' 
for i = 0, ndim-2 do string = string + string(ngrid[i], ', ', format='(i0,a)')
string = string + string(ngrid[i], ')', format='(i0,a)')
checkthisval = execute(string)

end