update position validation

src/pynwb/ecephys.py

@@ -1,4 +1,5 @@
 import warnings
+import numpy as np
 from collections.abc import Iterable
 
 from hdmf.common import DynamicTableRegion
@@ -27,25 +28,29 @@ class ElectrodeGroup(NWBContainer):
             {'name': 'device', 'type': Device, 'doc': 'the device that was used to record from this electrode group'},
             {'name': 'position', 'type': 'array_data',
              'doc': 'Compound dataset with stereotaxic position of this electrode group (x, y, z). '
-                    'Each element of the data array must have three elements or the dtype of the '
+                    'The data array must have three elements or the dtype of the '
                     'array must be ``(float, float, float)``', 'default': None})
     def __init__(self, **kwargs):
         args_to_set = popargs_to_dict(('description', 'location', 'device', 'position'), kwargs)
         super().__init__(**kwargs)
 
-        # position is a compound dataset, i.e., this must be an array with a compound data type of three floats
-        # or is a list/tuple of three entries or a list with a single element with three entries
-        if args_to_set['position'] is not None and len(args_to_set['position']) > 0:
-            # If we have a dtype, then check that it is valid length
-            is_valid_dtype = not hasattr(args_to_set['position'], 'dtype') or len(args_to_set['position'].dtype) == 3
-
-            # check data is a valid shape
-            is_valid_shape = len(args_to_set['position']) == 3 or \
-                     (len(args_to_set['position']) == 1 and len(args_to_set['position'][0]) == 3)
-
-            if not is_valid_dtype or not is_valid_shape:
-                raise ValueError('ElectrodeGroup position dataset must have three components (x, y, z) or [(x, y, z)] '
-                                 'but received: %s' % str(args_to_set['position']))
+        # position is a compound dataset, i.e., this must be a scalar with a
+        # compound data type of three floats or a list/tuple of three entries
+        position = args_to_set['position']
+        if position:
+            # check position argument is valid
+            position_dtype_invalid = (
+                (hasattr(position, 'dtype') and len(position.dtype) != 3) or
+                (not hasattr(position, 'dtype') and len(position) != 3) or
+                (len(np.shape(position)) > 1)
+            )
+            if position_dtype_invalid:
+                raise ValueError(f"ElectrodeGroup position argument must have three elements: x, y, z,"
+                                 f"but received: {position}")
+
+            # convert position to scalar with compound data type if needed
+            if not hasattr(position, 'dtype'):
+                args_to_set['position'] = np.array(tuple(position), dtype=[('x', float), ('y', float), ('z', float)])
 
         for key, val in args_to_set.items():
             setattr(self, key, val)