Merge pull request #1223 from kohr-h/phantom_min_max_pt

ENH: add min/max_pt to ellipsoid_phantom

odl/phantom/emission.py

@@ -104,19 +104,46 @@ def _derenzo_sources_2d():
             [1.0, 0.023968, 0.023968, 0.88528, -0.11791, 0.0]]
 
 
-def derenzo_sources(space):
+def derenzo_sources(space, min_pt=None, max_pt=None):
     """Create the PET/SPECT Derenzo sources phantom.
 
     The Derenzo phantom contains a series of circles of decreasing size.
 
     In 3d the phantom is simply the 2d phantom extended in the z direction as
     cylinders.
+
+    Parameters
+    ----------
+    space : `DiscreteLp`
+        Space in which the phantom should be created, must be 2- or
+        3-dimensional. If ``space.shape`` is 1 in an axis, a corresponding
+        slice of the phantom is created (instead of squashing the whole
+        phantom into the slice).
+    min_pt, max_pt : array-like, optional
+        If provided, use these vectors to determine the bounding box of the
+        phantom instead of ``space.min_pt`` and ``space.max_pt``.
+        It is currently required that ``min_pt >= space.min_pt`` and
+        ``max_pt <= space.max_pt``, i.e., shifting or scaling outside the
+        original space is not allowed.
+
+        Providing one of them results in a shift, e.g., for ``min_pt``::
+
+            new_min_pt = min_pt
+            new_max_pt = space.max_pt + (min_pt - space.min_pt)
+
+        Providing both results in a scaled version of the phantom.
+
+    Returns
+    -------
+    phantom : ``space`` element
+        The Derenzo source phantom in the given space.
     """
     if space.ndim == 2:
-        return ellipsoid_phantom(space, _derenzo_sources_2d())
+        return ellipsoid_phantom(space, _derenzo_sources_2d(), min_pt, max_pt)
     if space.ndim == 3:
         return ellipsoid_phantom(
-            space, cylinders_from_ellipses(_derenzo_sources_2d()))
+            space, cylinders_from_ellipses(_derenzo_sources_2d()),
+            min_pt, max_pt)
     else:
         raise ValueError('dimension not 2, no phantom available')