AstrowidgetsImageViewerMixin#

class jdaviz.core.astrowidgets_api.AstrowidgetsImageViewerMixin[source]#

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`	The zoom level for an image viewer (not linked by WCS).

Methods Summary

`add_markers`(table[, x_colname, y_colname, ...])	Creates markers w.r.t.
`center_on`(point)	Centers the view on a particular point on the top visible layer.
`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#

The zoom level for an image viewer (not linked by WCS).

Warning

When a viewer is linked by WCS, the result corresponds to the zoom_level of the reference data.

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)[source]#

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

Note

Use marker to change marker appearance.

Note

Once markers are added, linking cannot be changed. To change linking options, remove and re-add the markers manually.

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)[source]#

Centers the view on a particular point on the top visible layer. The data label of the top visible layer can be queried using the viewer’s top_visible_data_label property.

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()[source]#: This method must be called in child class __init__.

offset_by(dx, dy)[source]#

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)[source]#

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()[source]#: Delete all markers.

save(filename)[source]#

Save out the current image view to given PNG filename.

Parameters:

filenamestr: PNG filename. If the given file already exists, it will be silently overwritten.

set_colormap(cmap)[source]#

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)[source]#

Zoom in or out by the given factor.

Warning

When a viewer is linked by WCS, this method accidentally changes the center also; see the warning in zoom_level.

Parameters:

valint or float: The zoom level to zoom the image. See zoom_level.

Raises:

ValueError: Invalid zoom factor.