Merge pull request #119 from rayosborn/add-nxdata-functions

Add NXData functions

src/nexusformat/nexus/tree.py

@@ -6019,7 +6019,7 @@ def project(self, axes, limits=None, summed=True):
         Using the default `limits=None` should be used with caution, since it
         requires reading the entire data set into memory.
         """
-        signal_rank = self.nxsignal.ndim
+        signal_rank = self.ndim
         if not is_iterable(axes):
             axes = [axes]
         if limits is None:
@@ -6270,6 +6270,24 @@ def implot(self, fmt='', xmin=None, xmax=None, ymin=None, ymax=None,
         else:
             raise NeXusError("Invalid shape for RGB(A) image")
 
+    @property
+    def ndim(self):
+        """Rank of the NXdata signal."""
+        signal = self.nxsignal
+        if signal is not None:
+            return signal.ndim
+        else:
+            raise NeXusError("No signal defined for NXdata group")
+
+    @property
+    def shape(self):
+        """Shape of the NXdata signal."""
+        signal = self.nxsignal
+        if signal is not None:
+            return signal.shape
+        else:
+            raise NeXusError("No signal defined for NXdata group")
+
     @property
     def nxsignal(self):
         """NXfield containing the signal data."""

tests/test_data.py

@@ -19,6 +19,8 @@ def test_data_creation():
     assert "axes" in data.attrs
     assert len(data.attrs["axes"]) == 3
 
+    assert data.ndim == 3
+    assert data.shape == (2, 5, 10)
     assert data.nxsignal.nxname == "v"
     assert data.nxsignal.ndim == 3
     assert data.nxsignal.shape == (2, 5, 10)