Mailman 3 মার্চ 2018 - AstroPy

Aplpy FITSFigure does not open any window
by Vittorio_Roma2 23 মার্চ, 2019

23 মার্চ, 2019

Dear all I am having a problem with aplpy. I am using Python 3.5.2 under ubuntu 16.04 and installed aplpy version 1.1.1 through pip3 install aplpy The first problem arises when importing aplpy: import/home/vittorio/.local/lib/python3.5/site-packages/matplotlib/cbook/deprecation.py:106: MatplotlibDeprecationWarning: The mpl_toolkits.axes_grid module was deprecated in version 2.1. Use mpl_toolkits.axes_grid1 and mpl_toolkits.axisartist provies the same functionality instead. warnings.warn(message, mplDeprecation, stacklevel=1) I have tried to substitute mpl_toolkits.axes_grid1 with mpl_toolkits.axes_grid in core.py but then I got an error (and not a warning) saying that axes_grid1 does not have some method. This will just return a failure and stop everything. Anyways, when I do >>> fitsfile='somefile.fits' >>> F=aplpy.FITSFigure(fitsfile) WARNING: Cannot determine equinox. Assuming J2000. [aplpy.wcs_util] WARNING: Cannot determine equinox. Assuming J2000. [aplpy.wcs_util] >>> F.show_grayscale() INFO: Auto-setting vmin to 3.416e+03 [aplpy.core] INFO: Auto-setting vmax to 2.212e+04 [aplpy.core] No window at all is opening. I have also tried giving as input of FITSFIgure astropy.io.fits.open objects but again, no graphical window shows up. I have found some workaround, that is, after the above instructions, to give >>>hdu_list=fits.open(fitsfile) >>>image_data=hdu_list[0].data >>>plt.imshow(image_data,'gray',clim=[4500,9000]) >>>plt.show(block=False) This does open an astrometrized image, with the labels of the X and Y axis in the right place. However, this does not allow me to use any of the FITSFigure methods. Neither I can add subplots to put annotations. Finally, to add markers, I am forced to do another workaround: to give pixel coordinates like this >>>plt.scatter(pixcoords[:,0],pixcoords[:,1]) where pixcoords comes from WCS transformations. I have also tried a workaround, giving,e.g. >>>F.add_label(0.5,0.5,'ssss',relative=True) and do the plt.imshow and plt.show later, but this still does not work. To sum up, while it is true that I can live with the workarounds for some very basic figures, all of this is slowing down the script and I can't call any of the FITSFigure methods Any help would really be appreciated Best regards, Vittorio

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Project Examples
by Kenneth Adam Miller 29 মার্চ, 2018

29 মার্চ, 2018

Hello, I'm a PhD student at Purdue university, and I'm working on some private endeavors on my own. I would like to describe them at length to someone who might be interested in cooperating or helping. I want to automate the process of creating human-usable galaxy and astronomy pictures from raw telescope data. I need some python examples that allow me to: 1. Pull disparate wavelength data from a remote server so that the coordinates and time are coherent 2. Process the result into an image of an arbitrary size and precision 3. Designate the wavelength interval mappings Is there anyone that would be willing to talk to me on the phone shortly? I want to communicate my project goals in the hopes that perhaps there are some existing software libraries that can be shared or explained at length or a mailing list. I've crawled the webpages for information, although some of what I've asked might be there, I think the contact would always be helpful in the least.

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FITS cube with Faraday depth axis
by Hill, Alex 24 মার্চ, 2018

24 মার্চ, 2018

Hi all, I’m working with Faraday depth FITS cubes, where CTYPE3 = ‘RM’ and CUNIT3 = ‘rad/m2'. (CTYPE1=‘GLON-CAR’ and CTYPE2=‘GLAT-CAR’.) I would like to treat the Faraday depth cube like a spectral cube, for example calculating moments. I’m trying to load the cube using SpectralCube.read. It fails to read because the RM axis is not recognized as a spectral axis. Instead, the coordinate type for the RM axis is None: w.get_axis_types() output: [{'coordinate_type': 'celestial', 'group': 0, 'number': 0, 'scale': 'non-linear celestial'}, {'coordinate_type': 'celestial', 'group': 0, 'number': 1, 'scale': 'non-linear celestial'}, {'coordinate_type': None, 'group': 0, 'number': 0, 'scale': 'linear'}] I can hack it to work by loading the FITS header and changing the RM axis to a velocity axis: hdr['CTYPE3'] = 'VELO-LSR' hdr['CUNIT3'] = 'm/s' w = wcs.WCS(hdr) and then pass the data and hacked header to SpectralCube. However, is there a way to cleanly recognize a Faraday depth axis as a spectral axis? It looks to me like this would be somewhere in the WCS class, but I can’t find where in the code VELO-LSR, for example, gets recognized as a spectral axis. Cheers, Alex --------- Alex Hill University of British Columbia and Space Science Institute email: ashill(a)astro.ubc.ca Based at Dominion Radio Astrophysical Observatory, National Research Council Canada Mailing: PO Box 248, Penticton, BC V2A 6K3, Canada Physical: 717 White Lake Road, Kaleden, BC V0H 1K0, Canada phone: +1 250-497-2356

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Current best replacement for splot
by Nicholas Ross 18 মার্চ, 2018

18 মার্চ, 2018

Dear All, A colleague has suggested I use splot for investigating some optical spectra. However, I don’t have IRAF installed, and would be much keener to use a Python tool here. I know PyRAF exists, but the examples there seem extremely minimal. Aside from writing one’s own Python/AstroPy reader code, what is the current best replacement for splot and looking at e.g. optical spectra FITS data?? Yours, Nic

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Saving Cutout2D image to FITS
by Ivan Valtchanov 14 মার্চ, 2018

14 মার্চ, 2018

Hi all, I've been trying to use astropy.nddata Cutout2D to crop a large image. I don't see how to save the cutout result to a FITS file. cutout.writeto('image.fits') does not work and in the API I cannot find a method in the Cutout2D class that saves the result to a FITS file. is there a way to do it? Thanks, Ivan Valtchanov

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ANN: astropy bugfix releases v3.0.1 and v2.0.5 (LTS)
by Brigitta Sipocz 14 মার্চ, 2018

14 মার্চ, 2018

Dear all, Bugfix releases have been made for both the stable (v3.0.1) and LTS (v2.0.5) edition of astropy. They are available either on PyPI or on the usual conda channels. These releases contain the fix for a security vulnerability in the cfitsio library that was identified recently. The full list of fixes can be found in the changelog: https://github.com/astropy/astropy/blob/v3.0.1/CHANGES.rst <https://github.com/astropy/astropy/blob/v2.0.3/CHANGES.rst> Thank you for everyone who contributed for these releases! Cheers, Brigitta

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Making a GPL-v2+ Astropy affiliated package
by Singer, Leo P. (GSFC-6610) 5 মার্চ, 2018

5 মার্চ, 2018

Hi, I am starting the process of moving a large body of my own code [1], which is licensed under GPL-2+, to an Astropy affiliated package. I would like to keep the existing licensing. However, the Astropy affiliated package templated is all BSD licensed. Some files in my project (like setup.py and conftest.py) are largely unmodified from the template. Is this compatible with licensing my own project as a whole as GPL-2+? Is it sufficient to add my own LICENSE.md file, change the "Licensed under a 3-clause BSD style license" comment at the top of setup.py, and change the license entry in setup.cfg? Thanks, Leo ---- Dr. Leo P. Singer NASA Goddard Space Flight Center Astroparticle Physics Laboratory Code 661, 8800 Greenbelt Rd. Greenbelt, MD 20771, U.S.A. [1] https://git.ligo.org/leo-singer/ligo.skymap

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