AstrowidgetsImageViewerMixin

class jdaviz.core.astrowidgets_api.AstrowidgetsImageViewerMixin

Bases: object

This class implements astrowidgets API for Jdaviz image viewer. This does not provide a fully functional viewer, but rather should be used as mixin into an existing viewer subclass.

A child class that uses this must run init_astrowidgets_api() within its __init__.

Note

Do not use this for spectral or cube viewers.

Attributes Summary

RESERVED_MARKER_SET_NAMES
autocut_options	List of all available options for automatic image cut levels.
colormap_options	List of colormap names.
cuts	Current image cut levels.
marker	Marker to use.
stretch	The image stretching algorithm in use.
stretch_options	List of all available options for image stretching.
zoom_level	Zoom level:

Methods Summary

add_markers(table[, x_colname, y_colname, ...])	Creates markers w.r.t.
center_on(point)	Centers the view on a particular point.
init_astrowidgets_api()	This method must be called in child class __init__.
offset_by(dx, dy)	Move the center to a point that is given offset away from the current center.
remove_markers([marker_name])	Remove some but not all of the markers by name used when adding the markers.
reset_markers()	Delete all markers.
save(filename)	Save out the current image view to given PNG filename.
set_colormap(cmap)	Set colormap to the given colormap name.
zoom(val)	Zoom in or out by the given factor.

Attributes Documentation

RESERVED_MARKER_SET_NAMES = ['all']

autocut_options

List of all available options for automatic image cut levels.

colormap_options

List of colormap names.

cuts

Current image cut levels.

To set new cut levels, either provide a tuple of (low, high) values or one of the options from autocut_options.

marker

Marker to use.

Marker can be set as follows; e.g.:

{'color': 'red', 'alpha': 1.0, 'markersize': 3}
{'color': '#ff0000', 'alpha': 0.5, 'markersize': 10}
{'color': (1, 0, 0)}

The valid properties for Glue markers are listed at https://docs.glueviz.org/en/stable/api/glue.core.visual.VisualAttributes.html

stretch

The image stretching algorithm in use.

stretch_options

List of all available options for image stretching.

Their astropy.visualization counterparts are also accepted, as follows:

• 'arcsinh': astropy.visualization.AsinhStretch

• 'linear': astropy.visualization.LinearStretch

• 'log': astropy.visualization.LogStretch

• 'sqrt': astropy.visualization.SqrtStretch

zoom_level

Zoom level:

• 1 means real-pixel-size.

• 2 means zoomed in by a factor of 2.

• 0.5 means zoomed out by a factor of 2.

• ‘fit’ means zoomed to fit the whole image width into display.

Methods Documentation

add_markers(table, x_colname='x', y_colname='y', skycoord_colname='coord', use_skycoord=False, marker_name=None)

Creates markers w.r.t. the reference image at given points in the table.

Note

Use marker to change marker appearance.

Parameters

tableTable

Table containing marker locations.

x_colname, y_colnamestr

Column names for X and Y. Coordinates must be 0-indexed.

skycoord_colnamestr

Column name with SkyCoord objects.

use_skycoordbool

If True, use skycoord_colname to mark. Otherwise, use x_colname and y_colname.

marker_namestr, optional

Name to assign the markers in the table. Providing a name allows markers to be removed by name at a later time.

Raises

AttributeError

Sky coordinates are given but reference image does not have a valid WCS.

ValueError

Invalid marker name.

center_on(point)

Centers the view on a particular point.

Parameters

pointtuple or SkyCoord

If tuple of (X, Y) is given, it is assumed to be in data coordinates and 0-indexed.

Raises

AttributeError

Sky coordinates are given but image does not have a valid WCS.

init_astrowidgets_api()

This method must be called in child class __init__.

offset_by(dx, dy)

Move the center to a point that is given offset away from the current center.

Parameters

dx, dyfloat or Quantity

Offset value. Without a unit, assumed to be pixel offsets. If a unit is attached, offset by pixel or sky is assumed from the unit.

Raises

AttributeError

Sky offset is given but image does not have a valid WCS.

ValueError

Offsets are of different types.

astropy.units.core.UnitTypeError

Sky offset has invalid unit.

remove_markers(marker_name=None)

Remove some but not all of the markers by name used when adding the markers.

Parameters

marker_namestr

Name used when the markers were added. If not given, will delete markers added under default name.

reset_markers()

Delete all markers.

save(filename)

Save out the current image view to given PNG filename.

set_colormap(cmap)

Set colormap to the given colormap name.

Parameters

cmapstr

Colormap name. Possible values can be obtained from colormap_options().

Raises

ValueError

Invalid colormap name.

zoom(val)

Zoom in or out by the given factor.

Parameters

valint or float

The zoom level to zoom the image. See zoom_level.

Raises

ValueError

Invalid zoom factor.