Importing Data into Cubeviz

There are two primary ways in which you can load your data into the Cubeviz application. Cubeviz supports loading FITS files that can be parsed as Spectrum1D objects, in which case the application will attempt to automatically parse the data into the viewers as described in Displaying Cubes, including the 1D spectrum viewer. Data loaded into Cubeviz MUST contain valid WCS keywords. For more information on how Spectrum1D uses WCS, please go to the Spectrum1D defining WCS section. To check if your FITS file contains valid WCS keywords, please use Astropy WCS validate. For an example on loading a cube with valid WCS keywords, please see the Importing data via the API section below.

Importing data through the GUI

The first way you can load your data into the Cubeviz application is by clicking the Import button at the top left of the application’s user interface. This opens a dialogue where you can navigate your local file system (single click to enter a folder) and select the path of a file that can be parsed as a Spectrum1D:

After clicking Import, the data file will be parsed and loaded into the application. A green success message will appear if the data import was successful. Afterward, the new data set can be found in the Data tab of each viewer’s options menu as described in Selecting Data Set.

Importing data via the API

Alternatively, if you are working in a coding environment like a Jupyter notebook, you have access to the Cubeviz helper class API. Using this API, you can load data into the application through code using the load_data() method, which takes as input either the name of a local file or a Spectrum1D object.:

from jdaviz import Cubeviz
cubeviz = Cubeviz()
cubeviz.load_data("/Users/demouser/data/cube_file.fits")  # doctest: +SKIP
cubeviz.app

If instead you would like to load data you have created within the notebook, you can do the following:

import numpy as np
from astropy import units as u
from astropy.wcs import WCS
from specutils import Spectrum1D

flux = np.arange(16).reshape((2, 2, 4)) * u.Jy
wcs_dict = {"CTYPE1": "WAVE-LOG, "CTYPE2": "DEC--TAN", "CTYPE3": "RA---TAN",
            "CRVAL1": 4.622e-7, "CRVAL2": 27, "CRVAL3": 205,
            "CDELT1": 8e-11, "CDELT2": 0.0001, "CDELT3": -0.0001,
            "CRPIX1": 0, "CRPIX2": 0, "CRPIX3": 0}
w = WCS(wcs_dict)

cube = Spectrum1D(flux=flux, wcs=w)
cubeviz.load_data(cube)
cubeviz.app

To then extract your data from Cubeviz, please see the Using Cubeviz in a Jupyter Notebook section.