Linking of datasets in glue#

Note

The glue documentation includes a page about linking but the present page should be considered a more up-to-date guide with a focus on links useful to Jdaviz.

The ‘why’ of linking#

Why is linking needed in the first place? Linking in glue is a way to describe the relationship between datasets, with two main goals: to know how to overplot datasets, and to know how to apply a subset defined in one dataset (such as a spectral range) to another dataset. Having linking means being able to show, say, multiple spectra in the same plot, or multiple images that are aligned in the same image viewer, or contours on top of an image.

There are various ways of setting up links in glue, but the two main ways that have been discussed and used in Jdaviz are linking by pixel coordinates and by world coordinates (WCS).

Linking by WCS#

There are two main ways of linking by WCS, as follow.