My software career comes to an end on July 1, 2022 and with it will end active development of pyjs9. Please plan accordingly. Eric

.. image:: https://zenodo.org/badge/DOI/10.5281/zenodo.6675877.svg :target: https://doi.org/10.5281/zenodo.6675877

JS9 brings image display right into your browser::

• display URL-based FITS images and binary tables
• drag and drop FITS images and binary tables
• change the colormap and scale
• manipulate the contrast/bias with the mouse
• display pixel values and WCS position information
• create and manipulate geometric regions of interest
• add your own extensions using plugins and the Public API
• perform data analysis (local and server-side)
• display RGB composite images
• control JS9 from the command line
• print images
• much more ...

See: https://js9.si.edu for more information about JS9.

pyjs9.py connects Python and JS9 via the js9Helper.js back-end server::

• The JS9 class constructor connects to a single JS9 instance in a Web page.
• The JS9 object supports the JS9 Public API and a shorter command-line syntax.
• See: https://js9.si.edu/js9/help/publicapi.html for info about the public api
• Send/retrieve numpy arrays and astropy (or pyfits) hdulists to/from JS9.

Requirements: Python 3.5 or higher is required. Beyond that, pyjs9 communicates with a JS9 back-end Node server (which communicates with the browser itself). By default, pyjs9 utilizes the requests <http://www.python-requests.org/en/latest/> module to communicate with the JS9 back-end server. However, if you install python-socketio https://pypi.org/project/python-socketio, pyjs9 will use the faster, persistentsocket.io http://socket.io/` protocol.

Install from the repository using pip3, as usual::

> pip3 install git+https://github.com/ericmandel/pyjs9.git#egg=pyjs9

or from a local copy::

> pip3 install /path/to/local/copy

Mandatory dependencies::

requests

Optional dependencies::

numpy               # support for GetNumpy and SetNumpy methods
astropy             # support for GetFITS and SetFITS methods
python-socketio     # fast, persistent socket.io protocol, instead of html
                    # (install version 5.x, version 4.x is deprecated)

To run::

    > # ensure JS9 node-server is running ...
    > # visit your local JS9 Web page in your browser ...
> python
    ... (startup messages) ...
>>> import pyjs9
>>>
>>> j = pyjs9.JS9()        # default: connect to 'http://localhost'
>>>
>>> j.GetColormap()
{'bias': 0.5, 'colormap': 'grey', 'contrast': 1}
>>> j.SetColormap('red')
>>> j.cmap()
'red 1 0.5'
>>>
>>> hdul = j.GetFITS()
>>> hdul.info()
Filename: (No file associated with this HDUList)
No.    Name         Type      Cards   Dimensions   Format
0    PRIMARY     PrimaryHDU       6   (1024, 1024)   int32   
>>>
>>> narr = j.GetNumpy()
>>> narr.shape
(1024, 1024)

If you have internet connectivity, visit the JS9 Web page at https://js9.si.edu with your browser and::

> python
    ... (startup messages) ...
>>> import pyjs9
>>>
>>> j = pyjs9.JS9('https://js9.si.edu')        # connect to JS9 Web site
>>>
>>> j.GetColormap()
{'bias': 0.5, 'colormap': 'grey', 'contrast': 1}
>>>
>>> # etc ...