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Re: Possible bug in Fits.exe on Mac OSX Mathematica 6.0.3

• To: mathgroup at smc.vnet.net
• Subject: [mg91125] Re: Possible bug in Fits.exe on Mac OSX Mathematica 6.0.3
• From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
• Date: Thu, 7 Aug 2008 04:37:23 -0400 (EDT)
• Organization: The Open University, Milton Keynes, UK
• References: <g6c9ao$bv1$1@smc.vnet.net> <g6emtk$co2$1@smc.vnet.net>

Jean-Marc Gulliet wrote:
> yves.grosdidier at gmail.com wrote:
> 
>> I am trying to import a 4 dimensional data FITS file: 1024 x 1024 x
>> 272 x 1.
>>
>> This file is a bona fide FITS file, created by the Canadian Astronomy
>> Data Centre (more precisely it is one file extracted from the Canadian
>> Galactic Plane Survey: http://www1.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/cgps/query.html).
>>
>> After the command,
>>
>>  nebula=Import["CGPS_MB2_HI_line_image.fits.gz",{"GZIP","FITS"}];
>>
>> here is the error message I obtain:
>>
>> Import::errstruct: "Malformed data structure. \!\(\"Missing required \
>> keyword BITPIX\"\)."
>>
>> Using another software, I have checked that the required keyword
>> exists...
>>
>> My question: is Mathematica able to handle FITS files having more than
>> 2 dimensions (data cubes, etc.)?
> 
> FYIW,
> 
> I downloaded a FITS file (about 445 MB) from the website you mentioned. 
> Then I tried to import the compress as well as the uncompress file 
> without success but with a different message/problem from yours: the 
> import helper program Fits.exe quits unexpectedly. (The downloaded file 
> is good since MicroObservatory Image 2.0 [1] has no problem to read and 
> manipulate it.)
> 
> Configuration: 64-bit Intel Core 2 Duo 4 GB RAM Mac OSX Leopard 1.5.4 
> Mathematica 6.0.3
> 
> In[1]:= Timing[
>   image = Import["CGPS_MH1_HI_line_image.fits.gz", {"GZIP", "FITS"}]]
> 
> During evaluation of In[1]:= LinkObject::linkd:Unable to communicate \
> with closed link \
> LinkObject[/Applications/Mathematica.app/SystemFiles/Converters/\
> Binaries/MacOSX-x86-64/FITS.exe,9,9]. >>
> 
> Out[1]= {3.98607, $Failed}
> 
> In[2]:= Timing[image = Import["CGPS_MH1_HI_line_image.fits"]]
> 
> During evaluation of In[2]:= LinkObject::linkd:Unable to communicate \
> with closed link \
> LinkObject[/Applications/Mathematica.app/SystemFiles/Converters/\
> Binaries/MacOSX-x86-64/FITS.exe,10,9]. >>
> 
> Out[2]= {3.70389, $Failed}
> 
> In[3]:= $Version
> 
> Out[3]= "6.0 for Mac OS X x86 (64-bit) (May 21, 2008)"
> 
> 
> Regards,
> - Jean-Marc
> 
> [1] "MicroObservatory Image 2.0",
> http://mo-www.harvard.edu/MicroObservatoryImage/
> 

I submitted a bug report [TS 25343] about the error on my system (64-bit 
Intel Mac OS X Leopard 1.5.4 Mathematica 6.0.3).

It seems the error on my system is due to the size of the file I 
downloaded because the import program/Mathematica needs 4 times the 
file's size in memory to convert the file.

Here is an extract of last email I got from WRI:

"Then I am able to reproduce the second error that you receive; in this
case, I believe the problem is occurring because of the size of the file
that you are trying to import; a FITS file that is ~600 MB will take up
about 4 times as much memory space when imported into Mathematica, and
Mathematica will have a lot of problems when attempting to deal with a
file that requires that kind of space. I am able to import smaller FITS
files with no difficulty."

Regards,
-- Jean-Marc