custom_viewer

glue.custom_viewer(name, **kwargs)[source]

Create a custom interactive data viewer.

To use this, first create a new variable by calling custom_viewer. Then, register one or more viewer functions using decorators.

Parameters:name (str) – The name of the new viewer

Named arguments are used to build widgets and pass data to viewer functions. See specifying widgets below.

Example:

v = custom_viewer('My custom viewer', check=False, x='att(x)')

@v.setup
def setup_func(axes):
  ''' Setup the plot when the viewer is created '''
  ...

@v.plot_data
def plot_data_func(axes, check, style):
    ''' Visualize a full dataset '''
    ...

@v.plot_subset
def plot_subset_func(axes, check, style):
    ''' Visualize a subset '''
    ...

@v.update_settings
def update_settings_func(check):
    ''' Respond to the user changing a widget setting '''
    ...

@v.select
def select(roi, x):
  ''' Filter a dataset based on an roi. Return a boolean array '''
  ...

@v.make_selector
def make_selector_func(roi):
    ''' Turn a roi into a subset state '''
    ...

Specifying Widgets

Keywords passed to custom_viewer serve two purposes: they setup information to be passed into the viewer functions, and they create widgets. The type of widget that is created depends on the keyword value:

  • keyword=False | True creates a checkbox. The check state is passed as a Boolean into the viewer functions
  • keyword=(10, 20, [15]) creates a slider. The current value of the slider is passed as a number to the viewer functions. The first two numbers specify the minimum and maximum allowed value, while the optional third number specifies the initial value.
  • keyword=['a', 'b', 'c'] creates a dropdown menu. The current selection is passed as a string to the viewer functions.
  • keyword={'a':1, 'b':2} behaves similarly to the lists above, but uses the keys as dropdown labels and values as the setting passed to viewer functions.
  • keyword='att(foo)' doesn’t create any widget, but passes in the attribute named foo to the viewer functions, as an AttributeInfo object.
  • keyword='att' creates a dropdown to let the user select one of the attributes from the data. The selected attribute is passed as an AttributeInfo

Viewer Functions

Custom viewers can implement any of the following functions:

  • setup_func is called once, when the viewer is created.
  • plot_data is called to update the visualization of a full dataset.
  • plot_subset is used to visualize data subsets.
  • update_settings is called whenever a user modifies a widget setting.
  • select specifies how user-drawn regions on the viewer are used to filter data. It has access to an Roi input, and returns a Boolean array testing whether each element in a dataset is part of a subset.
  • make_selector is an alternative to select. Instead of returning
    an array, make_selector returns a SubsetState