When I read your original file I get (as you do) different results
with the plotting
and printing. If I modify BITPIX=-32 to BITPIX=32 I get consistent results.
Cheers,
Xavier Calbet
On Jan 31, 2008 3:41 PM, PAUL <[EMAIL PROTECTED]> wrote:
> Hmmm... that does seem strange, but then looking at all the headers
> of the FITS files I have, they all have BITPIX=-32. (Even FITS which
> have not been hacked using PDL). Is BITPIX actually still used?
>
> The sub which I used to write many FITS is here:
>
>
> ##################################################
> sub WriteFits { ##################################
> for($i=0;$i<$N_data;++$i) {
> ($suffix) = @_;
> $fitsname = $allnames[$i].$suffix.".fits";
> $newpid = $new_master_data(:,:,$i);
> $newpid = $newpid->float;
> $minpid = min($newpid);
> $maxpid = max($newpid);
> $hdr->{MINVAL} = $minpid;
> $hdr->{MAXVAL} = $maxpid;
> $newpid -> sethdr($hdr);
> wfits $newpid, $fitsname;
> print "FITS file FITS/$fitsname created!\n";
> system 'mv',$fitsname,$fitsdirectory;
> }
> system 'mv',$filename,$donedirectory;
> } # Ends the WriteFits sub. ######################
> ##################################################
>
> However, I've used this same routine to make hundreds of other FITS
> in this way, and I've never seen this weird problem before!
>
> cheers,
>
> Paul
>
>
>
>
> On 31 Jan 2008, at 14:17, Xavier Calbet wrote:
>
> > Don't know if it has anything to do with it, but your fits
> > header has a value of BITPIX=-32 (negative!!!)
> > This value is the number of bits per pixel in the image
> > and should always be positive.
> > If foo.fits has been written by PDL then it is strange.
> > Can you extract the PDL code where you write this file?
> >
> > Xavier Calbet
> >
> >
> > On Jan 31, 2008 2:58 PM, PAUL <[EMAIL PROTECTED]> wrote:
> >> Hi,
> >>
> >> I've encountered a strange effect when reading a fits file in the
> >> usual way (written with wfits, read with rfits as I usually do).
> >>
> >> The problem is, when I try and plot the piddle as a scatter plot
> >> ($win->points($x,$y)) it plots completely different values than when
> >> you simply print the piddle to the screen.
> >> I've tried writing the data to an ASCII file using "wcols" and then
> >> re-reading it, but this strange problem remains.
> >>
> >> What's going wrong? I've attached the fits file to the email.
> >>
> >> thanks,
> >>
> >> Paul
> >>
> >>
> >> _______________________________________________
> >> Perldl mailing list
> >> [email protected]
> >> http://mailman.jach.hawaii.edu/mailman/listinfo/perldl
> >>
> >>
>
>
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