DOC: Update transform.rst
Update incorrect labels.
@@ -77,13 +77,13 @@ grouped by the number of Cylinders.
The Altair shorthand string::
# ...
- y='mean(acceleration):Q',
+ x='mean(Acceleration):Q',
# ...
is made available for convenience, and is equivalent to the longer form::
# ...
- y=alt.Y(field='acceleration', aggregate='mean', type='quantitative'),
+ x=alt.X(field='Acceleration', aggregate='mean', type='quantitative'),
# ...
For more information on shorthand encodings specifications, see
