Values() operator accepts attribute names and indexes. Closes #27.

analysis-server/tests.py

@@ -527,6 +527,20 @@ def test_scan_null():
   array1 = random(5)
   scan(array1, format="null")
 
+def test_values_default():
+  array1 = random(5, attributes=["foo", "bar"])
+  b = values(array1)
+
+def test_values_index():
+  array1 = random(5, attributes=["foo", "bar"])
+  b = values(array1, 0)
+  c = values(array1, 1)
+
+def test_values_name():
+  array1 = random(5, attributes=["foo", "bar"])
+  numpy.testing.assert_array_equal(values(array1, "foo"), values(array1, 0))
+  numpy.testing.assert_array_equal(values(array1, "bar"), values(array1, 1))
+
 def test_zeros_1d():
   array1 = zeros(5)
   require_array_schema(array1, [("d0", "int64", 0, 5, 5)], [("val", "float64")])

packages/slycat/analysis/__init__.py

@@ -286,10 +286,19 @@ def value(self, source, attribute=0):
       raise
 
   def values(self, source, attribute=0):
-    """Returns a remote array attribute as a numpy array.
+    """Return an array attribute as a numpy array.
     """
     start_time = time.time()
 
+    # Handle attribute names ...
+    if isinstance(attribute, basestring):
+      for index, array_attribute in enumerate(source.attributes):
+        if array_attribute["name"] == attribute:
+          attribute = index
+          break
+      else:
+        raise InvalidArgument("Not an attribute name: {}".format(attribute))
+
     # Materialize every chunk into memory ...
     chunk_coordinates = []
     chunk_values = []