ParallelHoleCollimatorGeometry

class odl.applications.tomo.geometry.spect.ParallelHoleCollimatorGeometry(apart, dpart, det_radius, axis=(0, 0, 1), **kwargs)

Bases: Parallel3dAxisGeometry

Geometry for SPECT Parallel hole collimator.

For details, check the online docs.

__init__(apart, dpart, det_radius, axis=(0, 0, 1), **kwargs)

Initialize a new instance.

Parameters

apart1-dim. RectPartition

Partition of the angle interval.

dpart2-dim. RectPartition

Partition of the detector parameter rectangle.

det_radiuspositive float

Radius of the circular detector orbit.

axisarray-like, shape (3,), optional

Vector defining the fixed rotation axis of this geometry.

Other Parameters

orig_to_det_initarray-like, shape (3,), optional

Vector pointing towards the initial position of the detector reference point. The default depends on axis, see Notes. The zero vector is not allowed.

det_axes_init2-tuple of array-like’s (shape (3,)), optional

Initial axes defining the detector orientation. The default depends on axis, see Notes.

translationarray-like, shape (3,), optional

Global translation of the geometry. This is added last in any method that computes an absolute vector, e.g., det_refpoint, and also shifts the axis of rotation. Default: (0, 0, 0)

check_boundsbool, optional

If True, methods perform sanity checks on provided input parameters. Default: True

Notes

In the default configuration, the rotation axis is (0, 0, 1), the vector towards the initial detector reference point is (0, 1, 0), and the default detector axes are [(1, 0, 0), (0, 0, 1)]. If a different axis is provided, the new default initial position and the new default axes are the computed by rotating the original ones by a matrix that transforms (0, 0, 1) to the new (normalized) axis. This matrix is calculated with the rotation_matrix_from_to function. Expressed in code, we have

init_rot = rotation_matrix_from_to((0, 0, 1), axis)
orig_to_det_init = init_rot.dot((0, 1, 0))
det_axes_init[0] = init_rot.dot((1, 0, 0))
det_axes_init[1] = init_rot.dot((0, 0, 1))