diff --git a/pandas/plotting/_core.py b/pandas/plotting/_core.py index b15c5271ae3215..14cbe4543f7ff0 100644 --- a/pandas/plotting/_core.py +++ b/pandas/plotting/_core.py @@ -2604,26 +2604,73 @@ def hist(self, bins=10, **kwds): def kde(self, bw_method=None, ind=None, **kwds): """ - Kernel Density Estimate plot + Kernel Density Estimate plot using Gaussian kernels. + + In statistics, kernel density estimation (KDE) is a non-parametric way + to estimate the probability density function (PDF) of a random + variable. This function uses Gaussian kernels and includes automatic + bandwith determination. Parameters ---------- - bw_method: str, scalar or callable, optional - The method used to calculate the estimator bandwidth. This can be + bw_method : str, scalar or callable, optional + The method used to calculate the estimator bandwidth. This can be 'scott', 'silverman', a scalar constant or a callable. If None (default), 'scott' is used. See :class:`scipy.stats.gaussian_kde` for more information. ind : NumPy array or integer, optional - Evaluation points. If None (default), 1000 equally spaced points - are used. If `ind` is a NumPy array, the kde is evaluated at the - points passed. If `ind` is an integer, `ind` number of equally - spaced points are used. - `**kwds` : optional + Evaluation points for the estimated PDF. If None (default), + 1000 equally spaced points are used. If `ind` is a NumPy array, the + kde is evaluated at the points passed. If `ind` is an integer, + `ind` number of equally spaced points are used. + kwds : optional Keyword arguments to pass on to :py:meth:`pandas.Series.plot`. Returns ------- axes : matplotlib.AxesSubplot or np.array of them + + See also + -------- + :class:`scipy.stats.gaussian_kde` : Representation of a kernel-density + estimate using Gaussian kernels. This is the function used + internally to estimate the PDF. + + Examples + -------- + Given a ``Series`` of points randomly sampled from an unknown + distribution, estimate this distribution using KDE with automatic + bandwidth determination and plot the results, evaluating them at + 1000 equally spaced points (default): + + .. plot:: + :context: close-figs + + >>> s = pd.Series([1, 2, 2.5, 3, 3.5, 4, 5]) + >>> p = s.plot.kde() + + + An scalar fixed bandwidth can be specified. Using a too small bandwidth + can lead to overfitting, while a too large bandwidth can result in + underfitting: + + .. plot:: + :context: close-figs + + >>> p = s.plot.kde(bw_method=3) + + .. plot:: + :context: close-figs + + >>> p = s.plot.kde(bw_method=0.3) + + Finally, the `ind` parameter determines the evaluation points for the + plot of the estimated PDF: + + .. plot:: + :context: close-figs + + >>> p = s.plot.kde(ind=[1, 2, 3, 4, 5]) """ return self(kind='kde', bw_method=bw_method, ind=ind, **kwds)