Interactive Operations

The function interactive() simplifies the definition of operations that are automatically updated when an event is triggered. By default the operation is recomputed when the data or the axes of the original signal is changed.

>>> s = hs.signals.Signal1D(np.arange(10.))
>>> ssum = hs.interactive(s.sum, axis=0)
>>> ssum.data
array([45.])
>>> s.data /= 10
>>> s.events.data_changed.trigger(s)
>>> ssum.data
array([4.5])

Interactive operations can be performed in a chain.

>>> s = hs.signals.Signal1D(np.arange(2 * 3 * 4).reshape((2, 3, 4)))
>>> ssum = hs.interactive(s.sum, axis=0)
>>> ssum_mean = hs.interactive(ssum.mean, axis=0)
>>> ssum_mean.data
array([30.,  33.,  36.,  39.])
>>> s.data
array([[[ 0,  1,  2,  3],
        [ 4,  5,  6,  7],
        [ 8,  9, 10, 11]],

       [[12, 13, 14, 15],
        [16, 17, 18, 19],
        [20, 21, 22, 23]]])
>>> s.data *= 10
>>> s.events.data_changed.trigger(obj=s)
>>> ssum_mean.data
array([300.,  330.,  360.,  390.])

Cleaning up

When an interactive operation is no longer needed, call the Interactive.close method to disconnect all event handlers and release internal references. This prevents the operation from continuing to respond to changes in the original signal and avoids leaking memory through lingering event callbacks.

>>> from hyperspy.interactive import Interactive
>>> s = hs.signals.Signal1D(np.arange(10.))
>>> ssum = Interactive(s.sum, axis=0)
>>> ssum.out.data
array([45.])
>>> s.data /= 10
>>> ssum.close()
>>> s.events.data_changed.trigger(s)
>>> ssum.out.data  # no change after close
array([45.])