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Re: FITS IO Problem [message #70664 is a reply to message #70660]

Fri, 23 April 2010 20:05

John B
Messages: 5
Registered: April 2010

Junior Member

On Apr 23, 5:13 pm, wlandsman <wlands...@gmail.com> wrote:
> One possiblity is that you have an incompatible versions of mrdfits
> and fxposit.pro (a procedure it calls to open the FITS file).
> mrdfits.pro was modified in March 2009 to OPENR the file with the /
> SWAP_IF_LITTLE keyword, rather than explcitly performing the byte
> swapping. (This provides a significant speed improvement.)
> However, if you have a new version of mrdfits.pro but an old version
> of fxposit.pro then the byte swapping would not be perfomed, leading
> to nonsensical values such as you describe. (I'm not sure why the
> first row would be OK, though)

I updated to the latest version of astrolib (I was using a version in
Schlegel's idlutils), and I still get the same error.

>
> If that is not the problem, then the next step is to figure out
> whether the culprit is mrdfits.pro or mwrfits.pro. Can other FITS
> I/O programs read the file created by mwrfits.pro?
>

Readfits.pro is choking since this isn't a standard fits file (NAXIS
isn't defined). Is there another one I can use?

J

> --Wayne
>
> On Apr 23, 4:30 pm, John B <bochan...@gmail.com> wrote:
>
>> Hi All,
>
>> I am writing an anonymous structure (52 columns by 21 rows) out to a
>> FITS file, using mwrfits.pro from the astrolib library. When I take
>> that file and read it back in (from the same machine), I get garbage
>> values throughout the
>> structure. Nans, infs and just random longs... very confusing.
>> Neither program complains, and until now, both have worked
>> spectacularly.
>
>> I have noticed that the first row is preserved properly, and that I
>> can isolate a single row and write it out, then read it in, and it is
>> ok.
>
>> Any suggestions??
>
>> Thank you!
>
>

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[Message index]

		Re: FITS IO Problem By: John B on Mon, 26 April 2010 15:52
		Re: FITS IO Problem By: John B on Sun, 25 April 2010 09:37
		Re: FITS IO Problem By: Craig Markwardt on Sat, 24 April 2010 13:08
		Re: FITS IO Problem By: John B on Sat, 24 April 2010 06:18
		Re: FITS IO Problem By: wlandsman on Sat, 24 April 2010 05:09
		Re: FITS IO Problem By: John B on Fri, 23 April 2010 20:05
		Re: FITS IO Problem By: wlandsman on Fri, 23 April 2010 14:13
		Re: FITS IO Problem By: m_schellens on Mon, 21 June 2010 01:59

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