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Re: IDL 8.2.2 released [message #84051 is a reply to message #83973]

Fri, 26 April 2013 03:06

tom.grydeland
Messages: 51
Registered: September 2012

Member

On Tuesday, April 16, 2013 4:08:24 AM UTC, Chris Torrence wrote:

> This has been fixed for IDL 8.2.3.
> [...]

> Note that if you don't disable the refresh, then each time a new plot is added, IDL will recompute the plot range to make sure the axes cover all of the plots.

Obviously. What I tried to say was that the quadratic behaviour suggests to me that this recomputation queries _all_ existing objects in the plot, something which is quite unnecessary. The plot range necessary for all _previously_ added objects does not change as a result of adding another one.

This is quite orthogonal to whether refresh is disabled or not.

((In pseudocode of an AXIS object of some description, assuming BOX will compute the union of two bounding-box arguments, and REDUCE works as one would expect, this can be expressed as

self.bbox = BOX(self.bbox, newOjb.bbox) ; bbox kept in property of AXIS

instead of

bbox = REDUCE('BOX', self.objects) ; bbox recomputed and not kept

))

> the time for radial_antenna(12) went from 40 seconds down to around 4 seconds.

Obviously a great improvement, but I cannot shake a feeling that there must be at least another factor of 10 within reach.

For comparison, on our old compute-server (Dual-core AMD Opteron, 2.6 GHz, 5200 bogomips) and with X over the network, an old version of That Other Vectorized Language (r2008a) does radial_antenna with time per antenna of 0.75 ms consistently for n from 10 to 30 (100 to 900 antennas in the pattern).

On my desktop (i5, 3.2 GHz, 6400 bogomips), the time per antenna is 70 ms for n=6, 130 ms for n=10, 234 ms for n=14, and that is as far as my patience extends for now.

If you run the instrumented code below, the final plot should show a roughly constant value, not one that increases quadratically. Does it in 8.2.3?

function radial_antenna, n, length=length

if n_elements(length) eq 0 then length = 0.9

ii = indgen(n)-(n-1.)/2
xx = ii[*,ii]
yy = transpose(xx)
cg = plot(xx[*], yy[*], 'D', aspect_ratio=1)
cg.refresh, /disable

nx = n_elements(xx)
if nx mod 2 then begin
;; if there is an element in the centre, eliminate it
tmp = [indgen(nx/2), nx/2+1+indgen(nx/2)]
xx = xx[tmp]
yy = yy[tmp]
endif
th = atan(yy, xx)

tic
for ii=0L, n_elements(xx)-1 do begin
cx = length/2*[-1, 1]*cos(th[ii])
cy = length/2*[-1, 1]*sin(th[ii])
!null = plot(xx[ii]+cx, yy[ii]+cy, 'k', /current, /overplot)
!null = plot(xx[ii]-cy, yy[ii]+cx, 'r', /current, /overplot)
endfor

cg.refresh
return, toc() / n^2
end

;; main routine

nn = 6 + 4*indgen(3)
tt = 0. * nn

foreach ii, nn, idx do tt[idx] = radial_antenna(ii)

!null = plot(nn, tt)

end

> Chris

--T

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[Message index]

		IDL 8.2.2 released By: Mark Piper on Tue, 05 February 2013 09:39
		Re: IDL 8.2.2 released By: David Fanning on Wed, 06 February 2013 16:24
		Re: IDL 8.2.2 released By: Mark Piper on Thu, 07 February 2013 08:16
		Re: IDL 8.2.2 released By: Mark Piper on Wed, 06 February 2013 16:09
		Re: IDL 8.2.2 released By: tom.grydeland on Wed, 20 March 2013 02:58
		Re: IDL 8.2.2 released By: Mark Piper on Wed, 06 February 2013 16:00
		Re: IDL 8.2.2 released By: Matt[2] on Thu, 07 February 2013 08:20
		Re: IDL 8.2.2 released By: Mark Piper on Wed, 06 February 2013 15:23
		Re: IDL 8.2.2 released By: Bob[4] on Wed, 06 February 2013 13:23
		Re: IDL 8.2.2 released By: Bob[4] on Thu, 07 February 2013 10:53
		Re: IDL 8.2.2 released By: dain.cilke on Thu, 07 February 2013 14:07
		Re: IDL 8.2.2 released By: Louis Giglio on Wed, 06 February 2013 13:01
		Re: IDL 8.2.2 released By: Andy Sayer on Thu, 07 February 2013 06:22
		Re: IDL 8.2.2 released By: Fabzi on Wed, 06 February 2013 11:18
		Re: IDL 8.2.2 released By: David Fanning on Wed, 06 February 2013 10:24
		Re: IDL 8.2.2 released By: Mark Piper on Wed, 06 February 2013 09:20
		Re: IDL 8.2.2 released By: Mark Piper on Wed, 06 February 2013 09:18
		Re: IDL 8.2.2 released By: David Fanning on Wed, 06 February 2013 06:51
		Re: IDL 8.2.2 released By: Fabzi on Wed, 06 February 2013 06:37
		Re: IDL 8.2.2 released By: lecacheux.alain on Wed, 06 February 2013 04:29
		Re: IDL 8.2.2 released By: Fabzi on Wed, 06 February 2013 01:44
		Re: IDL 8.2.2 released By: wlandsman on Tue, 05 February 2013 23:29
		Re: IDL 8.2.2 released By: David Fanning on Tue, 05 February 2013 15:06
		Re: IDL 8.2.2 released By: wlandsman on Tue, 05 February 2013 14:28
		Re: IDL 8.2.2 released By: timothyja123 on Sat, 09 February 2013 02:44
		Re: IDL 8.2.2 released By: Matt Haffner on Fri, 08 February 2013 13:48
		Re: IDL 8.2.2 released By: Michael Galloy on Wed, 13 February 2013 16:19
		Re: IDL 8.2.2 released By: Mark Piper on Wed, 20 March 2013 14:10
		Re: IDL 8.2.2 released By: Fabzi on Fri, 08 February 2013 09:15
		Re: IDL 8.2.2 released By: Fabzi on Fri, 08 February 2013 09:04
		Re: IDL 8.2.2 released By: timothyja123 on Tue, 12 February 2013 16:43
		Re: IDL 8.2.2 released By: dain.cilke on Fri, 08 February 2013 08:24
		Re: IDL 8.2.2 released By: chris_torrence@NOSPAM on Fri, 08 February 2013 08:14
		Re: IDL 8.2.2 released By: Bob[4] on Thu, 07 February 2013 14:55
		Re: IDL 8.2.2 released By: dain.cilke on Thu, 07 February 2013 14:10
		Re: IDL 8.2.2 released By: Bob[4] on Thu, 07 February 2013 12:14
		Re: IDL 8.2.2 released By: David Fanning on Thu, 07 February 2013 11:15
		Re: IDL 8.2.2 released By: chris_torrence@NOSPAM on Thu, 07 February 2013 09:11
		Re: IDL 8.2.2 released By: Mark Piper on Thu, 07 February 2013 08:55
		Re: IDL 8.2.2 released By: David Fanning on Thu, 07 February 2013 08:21
		Re: IDL 8.2.2 released By: Mark Piper on Thu, 14 February 2013 08:23
		Re: IDL 8.2.2 released By: Michael Galloy on Wed, 13 February 2013 16:16
		Re: IDL 8.2.2 released By: timothyja123 on Wed, 13 February 2013 14:52
		Re: IDL 8.2.2 released By: Fabzi on Wed, 13 February 2013 02:04
		Re: IDL 8.2.2 released By: lecacheux.alain on Wed, 20 March 2013 09:07
		Re: IDL 8.2.2 released By: tom.grydeland on Thu, 21 March 2013 02:38
		Re: IDL 8.2.2 released By: Mark Piper on Thu, 21 March 2013 09:41
		Re: IDL 8.2.2 released By: chris_torrence@NOSPAM on Mon, 15 April 2013 21:08
		Re: IDL 8.2.2 released By: tom.grydeland on Fri, 26 April 2013 03:06
		Re: IDL 8.2.2 released By: chris_torrence@NOSPAM on Fri, 26 April 2013 14:33
		Re: IDL 8.2.2 released By: tushar on Thu, 25 April 2013 23:31

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