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Re: Cleaver 2d reverse indicies? [message #63310 is a reply to message #63308]

Mon, 03 November 2008 13:15

Chris[6]
Messages: 84
Registered: July 2008

Member

> bins_mean = fltarr(size(nd, /dim))
> nx = (size(nd, /dim))[0]
> ny = (size(nd, /dim))[1]
> FOR i = 0UL, nx-1 DO BEGIN
> FOR j = 0UL, ny-1 DO BEGIN
> ind_ri = [i+nx*j]
> IF ri[ind_ri] EQ ri[ind_ri+1] THEN CONTINUE ; nothing to do in
> this iteration
> ri_sel = ri[ri[ind_ri]:ri[ind_ri+1]-1]
> bins_mean[i, j] = mean(pxxm(ri_sel), /nan)
> ENDFOR
> ENDFOR

Well, it seems like you can definitely eliminated the nested loop:

FOR i = 0UL, nx * ny - 1, DO BEGIN
if ri[i] eq ri[i+1] then continue ; nothing to do here
ri_sel = ri[ri[i] : ri[i+1] - 1]
bins_mean[( i mod nx), (i / nx)] = mean(pxxm(ri_sel),/nan)
endfor

I've always wondered if there is a way to eliminated the first loop
when using reverse indices, but haven't thought of / seen a way to
yet.

chris

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[Message index]

		Re: Cleaver 2d reverse indicies? By: Jeremy Bailin on Tue, 04 November 2008 07:48
		Re: Cleaver 2d reverse indicies? By: Chris[6] on Tue, 04 November 2008 01:56
		Re: Cleaver 2d reverse indicies? By: Chris[6] on Mon, 03 November 2008 16:40
		Re: Cleaver 2d reverse indicies? By: Brian Larsen on Mon, 03 November 2008 13:26
		Re: Cleaver 2d reverse indicies? By: Chris[6] on Mon, 03 November 2008 13:15

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