Bugfix in string to layout conversion

field.py

@@ -62,7 +62,7 @@ class Field(object):
                        over dimension 0. Also allowed: the strings 'numpy' (0,1,..d) or 'reverseNumpy' (d, ..., 1, 0)
         """
         if isinstance(layout, str):
-            layout = layoutStringToTuple(layout, dim=spatialDimensions)
+            layout = spatialLayoutStringToTuple(layout, dim=spatialDimensions)
         shapeSymbol = IndexedBase(TypedSymbol(Field.SHAPE_PREFIX + fieldName, Field.SHAPE_DTYPE), shape=(1,))
         strideSymbol = IndexedBase(TypedSymbol(Field.STRIDE_PREFIX + fieldName, Field.STRIDE_DTYPE), shape=(1,))
         totalDimensions = spatialDimensions + indexDimensions
@@ -409,19 +409,29 @@ def createNumpyArrayWithLayout(shape, layout):
     return res
 
 
-def layoutStringToTuple(layoutStr, dim):
-    if layoutStr in ('fzyx', 'zyxf') and dim != 4:
-        if dim == 3:
-            return tuple(reversed(range(dim)))
-        else:
-            raise ValueError("Layout descriptor " + layoutStr + " only valid for dimension 4, not %d" % (dim,))
+def spatialLayoutStringToTuple(layoutStr, dim):
+    if layoutStr in ('fzyx', 'zyxf'):
+        assert dim <= 3
+        return tuple(reversed(range(dim)))
 
     if layoutStr == "fzyx" or layoutStr == 'f' or layoutStr == 'reverseNumpy':
         return tuple(reversed(range(dim)))
     elif layoutStr == 'c' or layoutStr == 'numpy':
         return tuple(range(dim))
+    raise ValueError("Unknown layout descriptor " + layoutStr)
+
+
+def layoutStringToTuple(layoutStr, dim):
+    if layoutStr == 'fzyx':
+        assert dim <= 4
+        return tuple(reversed(range(dim)))
     elif layoutStr == 'zyxf':
-        return tuple(reversed(range(dim-1))) + (dim,)
+        assert dim <= 4
+        return tuple(reversed(range(dim - 1))) + (dim-1,)
+    elif layoutStr == 'f' or layoutStr == 'reverseNumpy':
+        return tuple(reversed(range(dim)))
+    elif layoutStr == 'c' or layoutStr == 'numpy':
+        return tuple(range(dim))
     raise ValueError("Unknown layout descriptor " + layoutStr)