circle subpage

doc/user_guide/marks/circle.rst

@@ -0,0 +1,31 @@
+.. currentmodule:: altair
+
+.. _user-guide-circle-marks:
+
+Circle 
+~~~~~~
+
+``circle`` mark is similar to ``point`` mark, except that (1) the ``shape`` value is always set to ``circle`` (2) they are filled by default.
+
+Scatterplot with Circle 
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Here is an example scatter plot with ``circle`` marks:
+
+.. altair-plot::
+    import altair as alt
+    from vega_datasets import data
+
+    source = data.cars.url
+
+    alt.Chart(source).mark_circle().encode(
+        x = ('Horsepower:Q'),
+        y = ('Miles_per_Gallon:Q')
+    )
+
+Circle Config 
+^^^^^^^^^^^^^
+
+The ``circle`` property of the top-level ``config`` object sets the default properties for all circle marks. If mark property encoding channels are specified for marks, these config values will be overridden.
+
+The circle config can contain any circle mark properties (except ``type``, ``style``, and ``clip``).