indexed_data.py

from glue.core.data import BaseCartesianData
from glue.core.message import NumericalDataChangedMessage


class IndexedData(BaseCartesianData):
    """
    A dataset where some dimensions have been removed via indexing.
    """

    def __init__(self, original_data, indices):
        super(IndexedData, self).__init__()
        self.original_data = original_data
        self._indices = indices

    @property
    def indices(self):
        return self._indices

    @indices.setter
    def indices(self, value):
        self._indices = value
        if self.hub is not None:
            msg = NumericalDataChangedMessage(self)
            self.hub.broadcast(msg)

    @property
    def label(self):
        return "Indexed Data"

    @property
    def shape(self):
        shape = []
        for idim in range(self.original_data.ndim):
            if self.indices[idim] is None:
                shape.append(self.original_data.shape[idim])
        return shape

    @property
    def main_components(self):
        return self.original_data.main_components

    def get_kind(self, cid):
        return self.original_data.get_kind(cid)

    def _to_original_view(self, view):
        original_view = list(self.indices)
        idim_reduced = 0
        for idim in range(self.original_data.ndim):
            if original_view[idim] is None:
                if view is None:
                    original_view[idim] = slice(None)
                else:
                    original_view[idim] = view[idim_reduced]
                idim_reduced += 1
        return original_view

    def get_data(self, cid, view=None):
        original_view = self._to_original_view(view)
        return self.original_data.get_data(cid, view=original_view)

    def get_mask(self, subset_state, view=None):
        original_view = self._to_original_view(view)
        return self.original_data.get_mask(subset_state, view=original_view)

    def compute_fixed_resolution_buffer(self, *args, **kwargs):
        from glue.core.fixed_resolution_buffer import compute_fixed_resolution_buffer
        return compute_fixed_resolution_buffer(self, *args, **kwargs)

    # The following aren't correct yet

    def compute_statistic(self, *args, **kwargs):
        return self.original_data.compute_statistic(*args, **kwargs)

    def compute_histogram(self, *args, **kwargs):
        return self.original_data.compute_histogram(*args, **kwargs)


if __name__ == "__main__":

    # We now create a data object using the above class,
    # and launch a a glue session

    import numpy as np
    from glue.core import DataCollection
    from glue.core.data_factories import load_data
    from glue.app.qt.application import GlueApplication
    from glue.viewers.image.qt import ImageViewer

    data1 = load_data('/Users/tom/Data/PPV/l1448_13co_small.fits')
    data2 = IndexedData(data1, (None, 10, None))

    dc = DataCollection([data1, data2])

    ga = GlueApplication(dc)
    ga.new_data_viewer(ImageViewer, data=data1)
    ga.new_data_viewer(ImageViewer, data=data2)
    ga.start()