| Re: why is using objects so much slower ? [message #24577] |
Mon, 09 April 2001 01:11 |
Martin Schultz
Messages: 515
Registered: August 1997
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Senior Member |
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Henkie wrote:
>
> Hi,
>
> because I love object oriented programming, I decided to try the objects in
> IDL too. However, when using the objects to plot some of my stuff, it
> turned out to be soooooo sloooow. [...][/color]
Well, this is not the objects, but the rendering in the IDL object
graphics routines. At RSI they apparently have the idea that no later
than 2 years from now everyone will
sit in front of a machine with a sophisticated 3D rendering engine
(and that all the Linuxes will by then support 3D rendering natively
;-). May still be that direct graphics is a little faster for certain
applications. I'd dare to postulate the following theorem:
the more you care about individual pixels or line fragments, the
directer your graphics should be.
Martin
--
[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[ [[[[[[[
[[ Dr. Martin Schultz Max-Planck-Institut fuer Meteorologie [[
[[ Bundesstr. 55, 20146 Hamburg [[
[[ phone: +49 40 41173-308 [[
[[ fax: +49 40 41173-298 [[
[[ martin.schultz@dkrz.de [[
[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[ [[[[[[[
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| Re: why is using objects so much slower ? [message #24594 is a reply to message #24577] |
Fri, 06 April 2001 08:53  |
Pavel A. Romashkin
Messages: 531
Registered: November 2000
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Senior Member |
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I think the most important thing to remember is that Objects in IDL is
not the same as Object graphics. I also can say that from the 3
platforms I routinely use IDL on, the HP9000 is the one I dislike the
most. Object graphics are very slow on the terminals, because graphic
accelerators are just not present, and the software rendering is slow. I
did use OG for line plots for one simple reason: too lazy to write DG
substitutes for the existing ROI and ogWindow Pickdata and Select
methods. On a fast personal computer, OG is not much slower that DG.
Pavel
Henkie wrote:
>
> Hi,
>
> because I love object oriented programming, I decided to try the objects in
> IDL too. However, when using the objects to plot some of my stuff, it
> turned out to be soooooo sloooow. Really, I mean a factor of 10 or so, and
> I wasn't doing anything funky. Is this normal behaviour ? I'm actually
> quite disappointed about it that I can not use it this way. I must add that
> IDL on our HP9000 system isn't a speed champion (let alone the awfull
> pseudo-coloring : oops, my program ate all my colors), but at least it was
> useable.
>
> Greetz,
>
> Henk
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| Re: why is using objects so much slower ? [message #24596 is a reply to message #24594] |
Fri, 06 April 2001 06:14 |
davidf
Messages: 2866
Registered: September 1996
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Senior Member |
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Henkie (deckard_007nospam@deja.com) writes:
> because I love object oriented programming, I decided to try the objects in
> IDL too. However, when using the objects to plot some of my stuff, it
> turned out to be soooooo sloooow. Really, I mean a factor of 10 or so, and
> I wasn't doing anything funky. Is this normal behaviour ? I'm actually
> quite disappointed about it that I can not use it this way. I must add that
> IDL on our HP9000 system isn't a speed champion (let alone the awfull
> pseudo-coloring : oops, my program ate all my colors), but at least it was
> useable.
There is no question object graphics can sometimes be slower
than direct graphics. Often this is caused by less
than optimal programming practice, but it also has
to do with lugging a true 3D representation along everywhere
you go. To be honest, this has become less an issue
as computers have gotten faster.
But, line plots!? Why would you *want* to do those
in object graphics? If you love object programming,
code up an object to do a line plot in direct graphics.
You get about 99% of the benefit of object graphics in
an object that is fast and powerful. At least 90% of
the objects I write don't use the object graphics class
library at all.
Cheers,
David
--
David Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438 E-Mail: davidf@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155
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