DOC: improved the scatter method (#20118)

Author: DaniGate

pandas/plotting/_core.py

@@ -3151,23 +3151,82 @@ def pie(self, y=None, **kwds):
 
     def scatter(self, x, y, s=None, c=None, **kwds):
         """
-        Scatter plot
+        Create a scatter plot with varying marker point size and color.
+
+        The coordinates of each point are defined by two dataframe columns and
+        filled circles are used to represent each point. This kind of plot is
+        useful to see complex correlations between two variables. Points could
+        be for instance natural 2D coordinates like longitude and latitude in
+        a map or, in general, any pair of metrics that can be plotted against
+        each other.
 
         Parameters
         ----------
-        x, y : label or position, optional
-            Coordinates for each point.
+        x : int or str
+            The column name or column position to be used as horizontal
+            coordinates for each point.
+        y : int or str
+            The column name or column position to be used as vertical
+            coordinates for each point.
         s : scalar or array_like, optional
-            Size of each point.
-        c : label or position, optional
-            Color of each point.
-        `**kwds` : optional
-            Additional keyword arguments are documented in
-            :meth:`pandas.DataFrame.plot`.
+            The size of each point. Possible values are:
+
+            - A single scalar so all points have the same size.
+
+            - A sequence of scalars, which will be used for each point's size
+              recursively. For instance, when passing [2,14] all points size
+              will be either 2 or 14, alternatively.
+
+        c : str, int or array_like, optional
+            The color of each point. Possible values are:
+
+            - A single color string referred to by name, RGB or RGBA code,
+              for instance 'red' or '#a98d19'.
+
+            - A sequence of color strings referred to by name, RGB or RGBA
+              code, which will be used for each point's color recursively. For
+              intance ['green','yellow'] all points will be filled in green or
+              yellow, alternatively.
+
+            - A column name or position whose values will be used to color the
+              marker points according to a colormap.
+
+        **kwds
+            Keyword arguments to pass on to :meth:`pandas.DataFrame.plot`.
 
         Returns
         -------
         axes : :class:`matplotlib.axes.Axes` or numpy.ndarray of them
+
+        See Also
+        --------
+        matplotlib.pyplot.scatter : scatter plot using multiple input data
+            formats.
+
+        Examples
+        --------
+        Let's see how to draw a scatter plot using coordinates from the values
+        in a DataFrame's columns.
+
+        .. plot::
+            :context: close-figs
+
+            >>> df = pd.DataFrame([[5.1, 3.5, 0], [4.9, 3.0, 0], [7.0, 3.2, 1],
+            ...                    [6.4, 3.2, 1], [5.9, 3.0, 2]],
+            ...                   columns=['length', 'width', 'species'])
+            >>> ax1 = df.plot.scatter(x='length',
+            ...                       y='width',
+            ...                       c='DarkBlue')
+
+        And now with the color determined by a column as well.
+
+        .. plot::
+            :context: close-figs
+
+            >>> ax2 = df.plot.scatter(x='length',
+            ...                       y='width',
+            ...                       c='species',
+            ...                       colormap='viridis')
         """
         return self(kind='scatter', x=x, y=y, c=c, s=s, **kwds)