Exemple #1
0
    def calc_coords(self,
                    indices=None,
                    drop_zero=False,
                    frame_shape=None,
                    r=0):
        '''
        Shorthand to calculate peak coordinates.

        Parameters
        ----------

        indices : numpy.ndarray
            Indices to calculate coordinates for. Both an array of (y, x) pairs
            and the output of np.mgrid are supported.
        drop_zero : bool
            Drop the zero order peak. This is important for virtual darkfield imaging.
        frame_shape : Tuple[int, int]
            If set, the peaks are filtered with :meth:`~libertem.analysis.gridmatching.within_frame`
        r : float
            Radius for :meth:`~libertem.analysis.gridmatching.within_frame`

        Returns
        -------

        numpy.ndarray
            A list of (y, x) coordinate pairs for peaks

        Raises
        ------

        ValueError
            If the shape of :code:`indices` is not as expected.
        '''
        if indices is None:
            indices = self.indices
        s = indices.shape
        # Output of mgrid
        if (len(s) == 3) and (s[0] == 2):
            indices = np.concatenate(indices.T)
        # List of (i, j) pairs
        elif (len(s) == 2) and (s[1] == 2):
            pass
        else:
            raise ValueError(
                "Shape of indices is %s, expected (n, 2) or (2, n, m)" %
                str(indices.shape))

        selector = np.ones(len(indices), dtype=np.bool)
        if drop_zero:
            nz = np.any(indices != 0, axis=1)
            selector *= nz
        peaks = calc_coords(self.zero, self.a, self.b, indices)
        if frame_shape is not None:
            fy, fx = frame_shape
            selector *= within_frame(peaks, r, fy, fx)
        return peaks[selector]
Exemple #2
0
 def calculated_refineds(self):
     '''
     numpy.ndarray : Calculated peak positions based on lattice parameters and indices.
     '''
     return calc_coords(self.zero, self.a, self.b, self.indices)