| Re: IDL subroutine improvements [message #15170 is a reply to message #15102] |
Thu, 22 April 1999 00:00  |
David Foster
Messages: 341
Registered: January 1996
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Senior Member |
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wbiagiot@suffolk.lib.ny.us wrote:
>
> To all,
>
> This is a really small issue. I'm just wondering if anyone else has
> submitted an improvement to an existing IDL subroutine to RSI and seen it
> incorporated into a subsequent version of IDL? A while back I submitted
> (what I considered to be) a significant speed enhancement to the cross
> correlate and auto correlate functions with only minor modifications. My
> benchmarks were showing me about a 60%+ speed improvement (which is important
> if your code is constantly banging on these functions, like mine was). I had
> to convince the rep over a couple of emails what the advantage/improvement
> was.
>
Some time ago I had an ongoing argument with some of the folks in
technical support about their EXTRACT_SLICE.PRO routine. They claim
that with it you can extract "any" 2D slice from a 3D data-set
by defining angles of rotation etc. Problem is, the routine does
not deal with "exchange-of-axis" rotations well at all; if one of
your rotations is near 90 degrees, the resulting slice will NOT
be what you might expect.
I finally got one of the tech support people to agree that my
point was valid, that the documentation was misleading, and that
the routine did not give you what you might expect. But the author
of that routine denied the limitation, and to this date
the routine has not been changed (I wrote my own).
I had also informed them about a problem with SEARCH3D() in IDL 5,
in which choosing a boundary element would give *very* unpredictable
results. I don't believe this has been fixed either.
Just my .02.
Dave
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~
David S. Foster Univ. of California, San Diego
Programmer/Analyst Brain Image Analysis Laboratory
foster@bial1.ucsd.edu Department of Psychiatry
(619) 622-5892 8950 Via La Jolla Drive, Suite 2240
La Jolla, CA 92037
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~
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