Check numpy array type

5 files changed, 25 insertions, 16 deletions

diff --git a/python/astra/data2d.py b/python/astra/data2d.py
index 188ff69..6ab458f 100644
--- a/python/astra/data2d.py
+++ b/python/astra/data2d.py
@@ -65,12 +65,7 @@ def link(datatype, geometry, data):
     :returns: :class:`int` -- the ID of the constructed object.
     
     """
-    if not isinstance(data,np.ndarray):
-        raise ValueError("Input should be a numpy array")
-    if not data.dtype==np.float32:
-        raise ValueError("Numpy array should be float32")
-    if not (data.flags['C_CONTIGUOUS'] and data.flags['ALIGNED']):
-        raise ValueError("Numpy array should be C_CONTIGUOUS and ALIGNED")
+    checkArrayForLink(data)
     return d.create(datatype,geometry,data,True)
 
 def store(i, data):
diff --git a/python/astra/data3d.py b/python/astra/data3d.py
index b0d54b2..3eea0e3 100644
--- a/python/astra/data3d.py
+++ b/python/astra/data3d.py
@@ -26,7 +26,7 @@
 from . import data3d_c as d
 import numpy as np
 
-from .pythonutils import GPULink
+from .pythonutils import GPULink, checkArrayForLink
 
 def create(datatype,geometry,data=None):
     """Create a 3D object.
@@ -57,10 +57,7 @@ def link(datatype, geometry, data):
     if not isinstance(data,np.ndarray) and not isinstance(data,GPULink):
         raise TypeError("Input should be a numpy ndarray or GPULink object")
     if isinstance(data, np.ndarray):
-        if data.dtype != np.float32:
-            raise ValueError("Numpy array should be float32")
-        if not (data.flags['C_CONTIGUOUS'] and data.flags['ALIGNED']):
-            raise ValueError("Numpy array should be C_CONTIGUOUS and ALIGNED")
+        checkArrayForLink(data)
     return d.create(datatype,geometry,data,True)
 
 
diff --git a/python/astra/experimental.pyx b/python/astra/experimental.pyx
index 25ecb24..c76fcbe 100644
--- a/python/astra/experimental.pyx
+++ b/python/astra/experimental.pyx
@@ -168,9 +168,9 @@ IF HAVE_CUDA==True:
 
         :param projector_id: A 3D projector object handle
         :type datatype: :class:`int`
-        :param vol: The input data, as either a numpy array, or a GPULink object
+        :param vol: The pre-allocated output data, as either a numpy array, or a GPULink object
         :type datatype: :class:`numpy.ndarray` or :class:`astra.data3d.GPULink`
-        :param proj: The pre-allocated output data, either numpy array or GPULink
+        :param proj: The input data, either numpy array or GPULink
         :type datatype: :class:`numpy.ndarray` or :class:`astra.data3d.GPULink`
         """
         direct_FPBP3D(projector_id, vol, proj, "BP")
diff --git a/python/astra/pythonutils.py b/python/astra/pythonutils.py
index 715df30..ef49f97 100644
--- a/python/astra/pythonutils.py
+++ b/python/astra/pythonutils.py
@@ -29,6 +29,8 @@
 
 
 """
+import numpy as np
+
 
 def geom_size(geom, dim=None):
     """Returns the size of a volume or sinogram, based on the projection or volume geometry.
@@ -62,6 +64,19 @@ def geom_size(geom, dim=None):
 
     return s
 
+def checkArrayForLink(data):
+    """Check if a numpy array is suitable for direct usage (contiguous, etc.)
+
+    This function raises an exception if not.
+    """
+
+    if not isinstance(data, np.ndarray):
+        raise ValueError("Numpy array should be numpy.ndarray")
+    if data.dtype != np.float32:
+        raise ValueError("Numpy array should be float32")
+    if not (data.flags['C_CONTIGUOUS'] and data.flags['ALIGNED']):
+        raise ValueError("Numpy array should be C_CONTIGUOUS and ALIGNED")
+
 class GPULink(object):
     """Utility class for astra.data3d.link with a CUDA pointer
 
diff --git a/python/astra/utils.pyx b/python/astra/utils.pyx
index 3b6e3ff..12fc38c 100644
--- a/python/astra/utils.pyx
+++ b/python/astra/utils.pyx
@@ -45,7 +45,7 @@ from .PyXMLDocument cimport XMLDocument
 from .PyXMLDocument cimport XMLNode
 from .PyIncludes cimport *
 
-from .pythonutils import GPULink
+from .pythonutils import GPULink, checkArrayForLink
 
 cdef extern from "CFloat32CustomPython.h":
     cdef cppclass CFloat32CustomPython:
@@ -252,9 +252,10 @@ cdef CFloat32VolumeData3D* linkVolFromGeometry(CVolumeGeometry3D *pGeometry, dat
         data_shape = (data.z, data.y, data.x)
     if geom_shape != data_shape:
         raise ValueError(
-            "The dimensions of the data do not match those specified in the geometry.".format(data_shape, geom_shape))
+            "The dimensions of the data do not match those specified in the geometry: {} != {}".format(data_shape, geom_shape))
 
     if isinstance(data, np.ndarray):
+        checkArrayForLink(data)
         pCustom = <CFloat32CustomMemory*> new CFloat32CustomPython(data)
         pDataObject3D = new CFloat32VolumeData3DMemory(pGeometry, pCustom)
     elif isinstance(data, GPULink):
@@ -276,9 +277,10 @@ cdef CFloat32ProjectionData3D* linkProjFromGeometry(CProjectionGeometry3D *pGeom
         data_shape = (data.z, data.y, data.x)
     if geom_shape != data_shape:
         raise ValueError(
-            "The dimensions of the data do not match those specified in the geometry.".format(data_shape, geom_shape))
+            "The dimensions of the data do not match those specified in the geometry: {} != {}".format(data_shape, geom_shape))
 
     if isinstance(data, np.ndarray):
+        checkArrayForLink(data)
         pCustom = <CFloat32CustomMemory*> new CFloat32CustomPython(data)
         pDataObject3D = new CFloat32ProjectionData3DMemory(pGeometry, pCustom)
     elif isinstance(data, GPULink):