IPython FITS file plotting problem

Dear all,

I am facing a problem while running a script ( please find the attached
files - I am attaching both the ipython notebook version and also the python
script ).

I am trying to plot an array of values, write it into a FITS file format,
read it back again and plot it ---> I don't get the same plots!

I shall be highly obliged if you can kindly help me with this.

The following are the versions of my packages and compiler:

matplotlib : '2.0.0b1'

numpy : '1.11.0'

astropy : u'1.1.2'

python : 2.7

Sincerely,
Anik Halder

problem_fits_file.ipynb
<http://matplotlib.1069221.n5.nabble.com/file/n47271/problem_fits_file.ipynb>
problem_fits_file.py
<http://matplotlib.1069221.n5.nabble.com/file/n47271/problem_fits_file.py>

···

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I can reproduce your issue with matplotlib 2 beta1 but not with 1.51, See
https://gist.github.com/jenshnielsen/86d4a86d8f667fadddc09f88c5fb87e6 I
think this relates to the dtype of the data (see the last two cells of my
notebook) can you open an issue for this at github? It seems like the fits
data is converted from float32 to big endian float8.

best
Jens

···

On Fri, 1 Jul 2016 at 15:23 anikhalder <a.halder at jacobs-university.de> wrote:

Dear all,

I am facing a problem while running a script ( please find the attached
files - I am attaching both the ipython notebook version and also the
python
script ).

I am trying to plot an array of values, write it into a FITS file format,
read it back again and plot it ---> I don't get the same plots!

I shall be highly obliged if you can kindly help me with this.

The following are the versions of my packages and compiler:

matplotlib : '2.0.0b1'

numpy : '1.11.0'

astropy : u'1.1.2'

python : 2.7

Sincerely,
Anik Halder

problem_fits_file.ipynb
<
http://matplotlib.1069221.n5.nabble.com/file/n47271/problem_fits_file.ipynb
>
problem_fits_file.py
<http://matplotlib.1069221.n5.nabble.com/file/n47271/problem_fits_file.py>

--
View this message in context:
http://matplotlib.1069221.n5.nabble.com/IPython-FITS-file-plotting-problem-tp47271.html
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Sure. The bug report is up at at
https://github.com/matplotlib/matplotlib/issues/6671

In the mean time you can either switch to 1.5.x or change the code to

plt.imshow(Z_read.astype('<f8'), origin = "lower")

best
Jens

···

On Fri, 1 Jul 2016 at 16:49 Halder, Anik <a.halder at jacobs-university.de> wrote:

Hi Jens,

Thank you so very much for your help.

Unfortunately I'm really am not too familiar with github. Will it be
possible for you to open a discussion there and send me the link?

Will be very obliged if you could do so.

Thank you once again,

Anik
------------------------------
*From:* Jens Nielsen [jenshnielsen at gmail.com]
*Sent:* Friday, July 01, 2016 5:21 PM
*To:* Halder, Anik; matplotlib-users at python.org
*Subject:* Re: [Matplotlib-users] IPython FITS file plotting problem

I can reproduce your issue with matplotlib 2 beta1 but not with 1.51, See
https://gist.github.com/jenshnielsen/86d4a86d8f667fadddc09f88c5fb87e6 I
think this relates to the dtype of the data (see the last two cells of my
notebook) can you open an issue for this at github? It seems like the fits
data is converted from float32 to big endian float8.

best
Jens

On Fri, 1 Jul 2016 at 15:23 anikhalder <a.halder at jacobs-university.de> > wrote:

Dear all,

I am facing a problem while running a script ( please find the attached
files - I am attaching both the ipython notebook version and also the
python
script ).

I am trying to plot an array of values, write it into a FITS file format,
read it back again and plot it ---> I don't get the same plots!

I shall be highly obliged if you can kindly help me with this.

The following are the versions of my packages and compiler:

matplotlib : '2.0.0b1'

numpy : '1.11.0'

astropy : u'1.1.2'

python : 2.7

Sincerely,
Anik Halder

problem_fits_file.ipynb
<
http://matplotlib.1069221.n5.nabble.com/file/n47271/problem_fits_file.ipynb
>
problem_fits_file.py
<http://matplotlib.1069221.n5.nabble.com/file/n47271/problem_fits_file.py
>

--
View this message in context:
http://matplotlib.1069221.n5.nabble.com/IPython-FITS-file-plotting-problem-tp47271.html
Sent from the matplotlib - users mailing list archive at Nabble.com.
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