import importlib
from typing import List, Type # noqa
import warnings
from pandas.util._decorators import Appender
from pandas.core.dtypes.common import is_integer, is_list_like
from pandas.core.dtypes.generic import ABCDataFrame, ABCSeries
import pandas
from pandas.core.base import PandasObject
# Trigger matplotlib import, which implicitly registers our
# converts. Implicit registration is deprecated, and when enforced
# we can lazily import matplotlib.
try:
import pandas.plotting._matplotlib # noqa
except ImportError:
pass
def hist_series(
self,
by=None,
ax=None,
grid=True,
xlabelsize=None,
xrot=None,
ylabelsize=None,
yrot=None,
figsize=None,
bins=10,
**kwds
):
"""
Draw histogram of the input series using matplotlib.
Parameters
----------
by : object, optional
If passed, then used to form histograms for separate groups
ax : matplotlib axis object
If not passed, uses gca()
grid : bool, default True
Whether to show axis grid lines
xlabelsize : int, default None
If specified changes the x-axis label size
xrot : float, default None
rotation of x axis labels
ylabelsize : int, default None
If specified changes the y-axis label size
yrot : float, default None
rotation of y axis labels
figsize : tuple, default None
figure size in inches by default
bins : integer or sequence, default 10
Number of histogram bins to be used. If an integer is given, bins + 1
bin edges are calculated and returned. If bins is a sequence, gives
bin edges, including left edge of first bin and right edge of last
bin. In this case, bins is returned unmodified.
`**kwds` : keywords
To be passed to the actual plotting function
Returns
-------
matplotlib.AxesSubplot
A histogram plot.
See Also
--------
matplotlib.axes.Axes.hist : Plot a histogram using matplotlib.
"""
plot_backend = _get_plot_backend()
return plot_backend.hist_series(
self,
by=by,
ax=ax,
grid=grid,
xlabelsize=xlabelsize,
xrot=xrot,
ylabelsize=ylabelsize,
yrot=yrot,
figsize=figsize,
bins=bins,
**kwds
)
def hist_frame(
data,
column=None,
by=None,
grid=True,
xlabelsize=None,
xrot=None,
ylabelsize=None,
yrot=None,
ax=None,
sharex=False,
sharey=False,
figsize=None,
layout=None,
bins=10,
**kwds
):
"""
Make a histogram of the DataFrame's.
A `histogram`_ is a representation of the distribution of data.
This function calls :meth:`matplotlib.pyplot.hist`, on each series in
the DataFrame, resulting in one histogram per column.
.. _histogram: https://en.wikipedia.org/wiki/Histogram
Parameters
----------
data : DataFrame
The pandas object holding the data.
column : string or sequence
If passed, will be used to limit data to a subset of columns.
by : object, optional
If passed, then used to form histograms for separate groups.
grid : bool, default True
Whether to show axis grid lines.
xlabelsize : int, default None
If specified changes the x-axis label size.
xrot : float, default None
Rotation of x axis labels. For example, a value of 90 displays the
x labels rotated 90 degrees clockwise.
ylabelsize : int, default None
If specified changes the y-axis label size.
yrot : float, default None
Rotation of y axis labels. For example, a value of 90 displays the
y labels rotated 90 degrees clockwise.
ax : Matplotlib axes object, default None
The axes to plot the histogram on.
sharex : bool, default True if ax is None else False
In case subplots=True, share x axis and set some x axis labels to
invisible; defaults to True if ax is None otherwise False if an ax
is passed in.
Note that passing in both an ax and sharex=True will alter all x axis
labels for all subplots in a figure.
sharey : bool, default False
In case subplots=True, share y axis and set some y axis labels to
invisible.
figsize : tuple
The size in inches of the figure to create. Uses the value in
`matplotlib.rcParams` by default.
layout : tuple, optional
Tuple of (rows, columns) for the layout of the histograms.
bins : integer or sequence, default 10
Number of histogram bins to be used. If an integer is given, bins + 1
bin edges are calculated and returned. If bins is a sequence, gives
bin edges, including left edge of first bin and right edge of last
bin. In this case, bins is returned unmodified.
**kwds
All other plotting keyword arguments to be passed to
:meth:`matplotlib.pyplot.hist`.
Returns
-------
matplotlib.AxesSubplot or numpy.ndarray of them
See Also
--------
matplotlib.pyplot.hist : Plot a histogram using matplotlib.
Examples
--------
.. plot::
:context: close-figs
This example draws a histogram based on the length and width of
some animals, displayed in three bins
>>> df = pd.DataFrame({
... 'length': [1.5, 0.5, 1.2, 0.9, 3],
... 'width': [0.7, 0.2, 0.15, 0.2, 1.1]
... }, index= ['pig', 'rabbit', 'duck', 'chicken', 'horse'])
>>> hist = df.hist(bins=3)
"""
plot_backend = _get_plot_backend()
return plot_backend.hist_frame(
data,
column=column,
by=by,
grid=grid,
xlabelsize=xlabelsize,
xrot=xrot,
ylabelsize=ylabelsize,
yrot=yrot,
ax=ax,
sharex=sharex,
sharey=sharey,
figsize=figsize,
layout=layout,
bins=bins,
**kwds
)
def boxplot(
data,
column=None,
by=None,
ax=None,
fontsize=None,
rot=0,
grid=True,
figsize=None,
layout=None,
return_type=None,
**kwds
):
"""
Make a box plot from DataFrame columns.
Make a box-and-whisker plot from DataFrame columns, optionally grouped
by some other columns. A box plot is a method for graphically depicting
groups of numerical data through their quartiles.
The box extends from the Q1 to Q3 quartile values of the data,
with a line at the median (Q2). The whiskers extend from the edges
of box to show the range of the data. The position of the whiskers
is set by default to `1.5 * IQR (IQR = Q3 - Q1)` from the edges of the box.
Outlier points are those past the end of the whiskers.
For further details see
Wikipedia's entry for `boxplot <https://en.wikipedia.org/wiki/Box_plot>`_.
Parameters
----------
column : str or list of str, optional
Column name or list of names, or vector.
Can be any valid input to :meth:`pandas.DataFrame.groupby`.
by : str or array-like, optional
Column in the DataFrame to :meth:`pandas.DataFrame.groupby`.
One box-plot will be done per value of columns in `by`.
ax : object of class matplotlib.axes.Axes, optional
The matplotlib axes to be used by boxplot.
fontsize : float or str
Tick label font size in points or as a string (e.g., `large`).
rot : int or float, default 0
The rotation angle of labels (in degrees)
with respect to the screen coordinate system.
grid : bool, default True
Setting this to True will show the grid.
figsize : A tuple (width, height) in inches
The size of the figure to create in matplotlib.
layout : tuple (rows, columns), optional
For example, (3, 5) will display the subplots
using 3 columns and 5 rows, starting from the top-left.
return_type : {'axes', 'dict', 'both'} or None, default 'axes'
The kind of object to return. The default is ``axes``.
* 'axes' returns the matplotlib axes the boxplot is drawn on.
* 'dict' returns a dictionary whose values are the matplotlib
Lines of the boxplot.
* 'both' returns a namedtuple with the axes and dict.
* when grouping with ``by``, a Series mapping columns to
``return_type`` is returned.
If ``return_type`` is `None`, a NumPy array
of axes with the same shape as ``layout`` is returned.
**kwds
All other plotting keyword arguments to be passed to
:func:`matplotlib.pyplot.boxplot`.
Returns
-------
result
See Notes.
See Also
--------
Series.plot.hist: Make a histogram.
matplotlib.pyplot.boxplot : Matplotlib equivalent plot.
Notes
-----
The return type depends on the `return_type` parameter:
* 'axes' : object of class matplotlib.axes.Axes
* 'dict' : dict of matplotlib.lines.Line2D objects
* 'both' : a namedtuple with structure (ax, lines)
For data grouped with ``by``, return a Series of the above or a numpy
array:
* :class:`~pandas.Series`
* :class:`~numpy.array` (for ``return_type = None``)
Use ``return_type='dict'`` when you want to tweak the appearance
of the lines after plotting. In this case a dict containing the Lines
making up the boxes, caps, fliers, medians, and whiskers is returned.
Examples
--------
Boxplots can be created for every column in the dataframe
by ``df.boxplot()`` or indicating the columns to be used:
.. plot::
:context: close-figs
>>> np.random.seed(1234)
>>> df = pd.DataFrame(np.random.randn(10,4),
... columns=['Col1', 'Col2', 'Col3', 'Col4'])
>>> boxplot = df.boxplot(column=['Col1', 'Col2', 'Col3'])
Boxplots of variables distributions grouped by the values of a third
variable can be created using the option ``by``. For instance:
.. plot::
:context: close-figs
>>> df = pd.DataFrame(np.random.randn(10, 2),
... columns=['Col1', 'Col2'])
>>> df['X'] = pd.Series(['A', 'A', 'A', 'A', 'A',
... 'B', 'B', 'B', 'B', 'B'])
>>> boxplot = df.boxplot(by='X')
A list of strings (i.e. ``['X', 'Y']``) can be passed to boxplot
in order to group the data by combination of the variables in the x-axis:
.. plot::
:context: close-figs
>>> df = pd.DataFrame(np.random.randn(10,3),
... columns=['Col1', 'Col2', 'Col3'])
>>> df['X'] = pd.Series(['A', 'A', 'A', 'A', 'A',
... 'B', 'B', 'B', 'B', 'B'])
>>> df['Y'] = pd.Series(['A', 'B', 'A', 'B', 'A',
... 'B', 'A', 'B', 'A', 'B'])
>>> boxplot = df.boxplot(column=['Col1', 'Col2'], by=['X', 'Y'])
The layout of boxplot can be adjusted giving a tuple to ``layout``:
.. plot::
:context: close-figs
>>> boxplot = df.boxplot(column=['Col1', 'Col2'], by='X',
... layout=(2, 1))
Additional formatting can be done to the boxplot, like suppressing the grid
(``grid=False``), rotating the labels in the x-axis (i.e. ``rot=45``)
or changing the fontsize (i.e. ``fontsize=15``):
.. plot::
:context: close-figs
>>> boxplot = df.boxplot(grid=False, rot=45, fontsize=15)
The parameter ``return_type`` can be used to select the type of element
returned by `boxplot`. When ``return_type='axes'`` is selected,
the matplotlib axes on which the boxplot is drawn are returned:
>>> boxplot = df.boxplot(column=['Col1','Col2'], return_type='axes')
>>> type(boxplot)
<class 'matplotlib.axes._subplots.AxesSubplot'>
When grouping with ``by``, a Series mapping columns to ``return_type``
is returned:
>>> boxplot = df.boxplot(column=['Col1', 'Col2'], by='X',
... return_type='axes')
>>> type(boxplot)
<class 'pandas.core.series.Series'>
If ``return_type`` is `None`, a NumPy array of axes with the same shape
as ``layout`` is returned:
>>> boxplot = df.boxplot(column=['Col1', 'Col2'], by='X',
... return_type=None)
>>> type(boxplot)
<class 'numpy.ndarray'>
"""
plot_backend = _get_plot_backend("matplotlib")
return plot_backend.boxplot(
data,
column=column,
by=by,
ax=ax,
fontsize=fontsize,
rot=rot,
grid=grid,
figsize=figsize,
layout=layout,
return_type=return_type,
**kwds
)
@Appender(boxplot.__doc__)
def boxplot_frame(
self,
column=None,
by=None,
ax=None,
fontsize=None,
rot=0,
grid=True,
figsize=None,
layout=None,
return_type=None,
**kwds
):
plot_backend = _get_plot_backend()
return plot_backend.boxplot_frame(
self,
column=column,
by=by,
ax=ax,
fontsize=fontsize,
rot=rot,
grid=grid,
figsize=figsize,
layout=layout,
return_type=return_type,
**kwds
)
def boxplot_frame_groupby(
grouped,
subplots=True,
column=None,
fontsize=None,
rot=0,
grid=True,
ax=None,
figsize=None,
layout=None,
sharex=False,
sharey=True,
**kwds
):
"""
Make box plots from DataFrameGroupBy data.
Parameters
----------
grouped : Grouped DataFrame
subplots : bool
* ``False`` - no subplots will be used
* ``True`` - create a subplot for each group
column : column name or list of names, or vector
Can be any valid input to groupby
fontsize : int or string
rot : label rotation angle
grid : Setting this to True will show the grid
ax : Matplotlib axis object, default None
figsize : A tuple (width, height) in inches
layout : tuple (optional)
(rows, columns) for the layout of the plot
sharex : bool, default False
Whether x-axes will be shared among subplots
.. versionadded:: 0.23.1
sharey : bool, default True
Whether y-axes will be shared among subplots
.. versionadded:: 0.23.1
`**kwds` : Keyword Arguments
All other plotting keyword arguments to be passed to
matplotlib's boxplot function
Returns
-------
dict of key/value = group key/DataFrame.boxplot return value
or DataFrame.boxplot return value in case subplots=figures=False
Examples
--------
>>> import itertools
>>> tuples = [t for t in itertools.product(range(1000), range(4))]
>>> index = pd.MultiIndex.from_tuples(tuples, names=['lvl0', 'lvl1'])
>>> data = np.random.randn(len(index),4)
>>> df = pd.DataFrame(data, columns=list('ABCD'), index=index)
>>>
>>> grouped = df.groupby(level='lvl1')
>>> boxplot_frame_groupby(grouped)
>>>
>>> grouped = df.unstack(level='lvl1').groupby(level=0, axis=1)
>>> boxplot_frame_groupby(grouped, subplots=False)
"""
plot_backend = _get_plot_backend()
return plot_backend.boxplot_frame_groupby(
grouped,
subplots=subplots,
column=column,
fontsize=fontsize,
rot=rot,
grid=grid,
ax=ax,
figsize=figsize,
layout=layout,
sharex=sharex,
sharey=sharey,
**kwds
)
class PlotAccessor(PandasObject):
"""
Make plots of Series or DataFrame using the backend specified by the
option ``plotting.backend``. By default, matplotlib is used.
Parameters
----------
data : Series or DataFrame
The object for which the method is called
x : label or position, default None
Only used if data is a DataFrame.
y : label, position or list of label, positions, default None
Allows plotting of one column versus another. Only used if data is a
DataFrame.
kind : str
- 'line' : line plot (default)
- 'bar' : vertical bar plot
- 'barh' : horizontal bar plot
- 'hist' : histogram
- 'box' : boxplot
- 'kde' : Kernel Density Estimation plot
- 'density' : same as 'kde'
- 'area' : area plot
- 'pie' : pie plot
- 'scatter' : scatter plot
- 'hexbin' : hexbin plot
figsize : a tuple (width, height) in inches
use_index : bool, default True
Use index as ticks for x axis
title : string or list
Title to use for the plot. If a string is passed, print the string
at the top of the figure. If a list is passed and `subplots` is
True, print each item in the list above the corresponding subplot.
grid : bool, default None (matlab style default)
Axis grid lines
legend : False/True/'reverse'
Place legend on axis subplots
style : list or dict
matplotlib line style per column
logx : bool or 'sym', default False
Use log scaling or symlog scaling on x axis
.. versionchanged:: 0.25.0
logy : bool or 'sym' default False
Use log scaling or symlog scaling on y axis
.. versionchanged:: 0.25.0
loglog : bool or 'sym', default False
Use log scaling or symlog scaling on both x and y axes
.. versionchanged:: 0.25.0
xticks : sequence
Values to use for the xticks
yticks : sequence
Values to use for the yticks
xlim : 2-tuple/list
ylim : 2-tuple/list
rot : int, default None
Rotation for ticks (xticks for vertical, yticks for horizontal
plots)
fontsize : int, default None
Font size for xticks and yticks
colormap : str or matplotlib colormap object, default None
Colormap to select colors from. If string, load colormap with that
name from matplotlib.
colorbar : bool, optional
If True, plot colorbar (only relevant for 'scatter' and 'hexbin'
plots)
position : float
Specify relative alignments for bar plot layout.
From 0 (left/bottom-end) to 1 (right/top-end). Default is 0.5
(center)
table : bool, Series or DataFrame, default False
If True, draw a table using the data in the DataFrame and the data
will be transposed to meet matplotlib's default layout.
If a Series or DataFrame is passed, use passed data to draw a
table.
yerr : DataFrame, Series, array-like, dict and str
See :ref:`Plotting with Error Bars <visualization.errorbars>` for
detail.
xerr : DataFrame, Series, array-like, dict and str
Equivalent to yerr.
mark_right : bool, default True
When using a secondary_y axis, automatically mark the column
labels with "(right)" in the legend
`**kwds` : keywords
Options to pass to matplotlib plotting method
Returns
-------
:class:`matplotlib.axes.Axes` or numpy.ndarray of them
If the backend is not the default matplotlib one, the return value
will be the object returned by the backend.
Notes
-----
- See matplotlib documentation online for more on this subject
- If `kind` = 'bar' or 'barh', you can specify relative alignments
for bar plot layout by `position` keyword.
From 0 (left/bottom-end) to 1 (right/top-end). Default is 0.5
(center)
"""
_common_kinds = ("line", "bar", "barh", "kde", "density", "area", "hist", "box")
_series_kinds = ("pie",)
_dataframe_kinds = ("scatter", "hexbin")
_kind_aliases = {"density": "kde"}
_all_kinds = _common_kinds + _series_kinds + _dataframe_kinds
def __init__(self, data):
self._parent = data
@staticmethod
def _get_call_args(backend_name, data, args, kwargs):
"""
This function makes calls to this accessor `__call__` method compatible
with the previous `SeriesPlotMethods.__call__` and
`DataFramePlotMethods.__call__`. Those had slightly different
signatures, since `DataFramePlotMethods` accepted `x` and `y`
parameters.
"""
if isinstance(data, ABCSeries):
arg_def = [
("kind", "line"),
("ax", None),
("figsize", None),
("use_index", True),
("title", None),
("grid", None),
("legend", False),
("style", None),
("logx", False),
("logy", False),
("loglog", False),
("xticks", None),
("yticks", None),
("xlim", None),
("ylim", None),
("rot", None),
("fontsize", None),
("colormap", None),
("table", False),
("yerr", None),
("xerr", None),
("label", None),
("secondary_y", False),
]
elif isinstance(data, ABCDataFrame):
arg_def = [
("x", None),
("y", None),
("kind", "line"),
("ax", None),
("subplots", False),
("sharex", None),
("sharey", False),
("layout", None),
("figsize", None),
("use_index", True),
("title", None),
("grid", None),
("legend", True),
("style", None),
("logx", False),
("logy", False),
("loglog", False),
("xticks", None),
("yticks", None),
("xlim", None),
("ylim", None),
("rot", None),
("fontsize", None),
("colormap", None),
("table", False),
("yerr", None),
("xerr", None),
("secondary_y", False),
("sort_columns", False),
]
else:
raise TypeError(
(
"Called plot accessor for type {}, expected " "Series or DataFrame"
).format(type(data).__name__)
)
if args and isinstance(data, ABCSeries):
msg = (
"`Series.plot()` should not be called with positional "
"arguments, only keyword arguments. The order of "
"positional arguments will change in the future. "
"Use `Series.plot({})` instead of `Series.plot({})`."
)
positional_args = str(args)[1:-1]
keyword_args = ", ".join(
"{}={!r}".format(name, value)
for (name, default), value in zip(arg_def, args)
)
warnings.warn(
msg.format(keyword_args, positional_args), FutureWarning, stacklevel=3
)
pos_args = {name: value for value, (name, _) in zip(args, arg_def)}
if backend_name == "pandas.plotting._matplotlib":
kwargs = dict(arg_def, **pos_args, **kwargs)
else:
kwargs = dict(pos_args, **kwargs)
x = kwargs.pop("x", None)
y = kwargs.pop("y", None)
kind = kwargs.pop("kind", "line")
return x, y, kind, kwargs
def __call__(self, *args, **kwargs):
plot_backend = _get_plot_backend()
x, y, kind, kwargs = self._get_call_args(
plot_backend.__name__, self._parent, args, kwargs
)
kind = self._kind_aliases.get(kind, kind)
if kind not in self._all_kinds:
raise ValueError("{} is not a valid plot kind".format(kind))
# The original data structured can be transformed before passed to the
# backend. For example, for DataFrame is common to set the index as the
# `x` parameter, and return a Series with the parameter `y` as values.
data = self._parent.copy()
if isinstance(data, pandas.core.dtypes.generic.ABCSeries):
kwargs["reuse_plot"] = True
if kind in self._dataframe_kinds:
if isinstance(data, ABCDataFrame):
return plot_backend.plot(data, x=x, y=y, kind=kind, **kwargs)
else:
raise ValueError(
("plot kind {} can only be used for " "data frames").format(kind)
)
elif kind in self._series_kinds:
if isinstance(data, ABCDataFrame):
if y is None and kwargs.get("subplots") is False:
msg = "{} requires either y column or 'subplots=True'"
raise ValueError(msg.format(kind))
elif y is not None:
if is_integer(y) and not data.columns.holds_integer():
y = data.columns[y]
# converted to series actually. copy to not modify
data = data[y].copy()
data.index.name = y
elif isinstance(data, ABCDataFrame):
data_cols = data.columns
if x is not None:
if is_integer(x) and not data.columns.holds_integer():
x = data_cols[x]
elif not isinstance(data[x], ABCSeries):
raise ValueError("x must be a label or position")
data = data.set_index(x)
if y is not None:
# check if we have y as int or list of ints
int_ylist = is_list_like(y) and all(is_integer(c) for c in y)
int_y_arg = is_integer(y) or int_ylist
if int_y_arg and not data.columns.holds_integer():
y = data_cols[y]
label_kw = kwargs["label"] if "label" in kwargs else False
for kw in ["xerr", "yerr"]:
if kw in kwargs and (
isinstance(kwargs[kw], str) or is_integer(kwargs[kw])
):
try:
kwargs[kw] = data[kwargs[kw]]
except (IndexError, KeyError, TypeError):
pass
# don't overwrite
data = data[y].copy()
if isinstance(data, ABCSeries):
label_name = label_kw or y
data.name = label_name
else:
match = is_list_like(label_kw) and len(label_kw) == len(y)
if label_kw and not match:
raise ValueError(
"label should be list-like and same length as y"
)
label_name = label_kw or data.columns
data.columns = label_name
return plot_backend.plot(data, kind=kind, **kwargs)
def line(self, x=None, y=None, **kwargs):
"""
Plot Series or DataFrame as lines.
This function is useful to plot lines using DataFrame's values
as coordinates.
Parameters
----------
x : int or str, optional
Columns to use for the horizontal axis.
Either the location or the label of the columns to be used.
By default, it will use the DataFrame indices.
y : int, str, or list of them, optional
The values to be plotted.
Either the location or the label of the columns to be used.
By default, it will use the remaining DataFrame numeric columns.
**kwds
Keyword arguments to pass on to :meth:`DataFrame.plot`.
Returns
-------
:class:`matplotlib.axes.Axes` or :class:`numpy.ndarray`
Return an ndarray when ``subplots=True``.
See Also
--------
matplotlib.pyplot.plot : Plot y versus x as lines and/or markers.
Examples
--------
.. plot::
:context: close-figs
>>> s = pd.Series([1, 3, 2])
>>> s.plot.line()
.. plot::
:context: close-figs
The following example shows the populations for some animals
over the years.
>>> df = pd.DataFrame({
... 'pig': [20, 18, 489, 675, 1776],
... 'horse': [4, 25, 281, 600, 1900]
... }, index=[1990, 1997, 2003, 2009, 2014])
>>> lines = df.plot.line()
.. plot::
:context: close-figs
An example with subplots, so an array of axes is returned.
>>> axes = df.plot.line(subplots=True)
>>> type(axes)
<class 'numpy.ndarray'>
.. plot::
:context: close-figs
The following example shows the relationship between both
populations.
>>> lines = df.plot.line(x='pig', y='horse')
"""
return self(kind="line", x=x, y=y, **kwargs)
def bar(self, x=None, y=None, **kwargs):
"""
Vertical bar plot.
A bar plot is a plot that presents categorical data with
rectangular bars with lengths proportional to the values that they
represent. A bar plot shows comparisons among discrete categories. One
axis of the plot shows the specific categories being compared, and the
other axis represents a measured value.
Parameters
----------
x : label or position, optional
Allows plotting of one column versus another. If not specified,
the index of the DataFrame is used.
y : label or position, optional
Allows plotting of one column versus another. If not specified,
all numerical columns are used.
**kwds
Additional keyword arguments are documented in
:meth:`DataFrame.plot`.
Returns
-------
matplotlib.axes.Axes or np.ndarray of them
An ndarray is returned with one :class:`matplotlib.axes.Axes`
per column when ``subplots=True``.
See Also
--------
DataFrame.plot.barh : Horizontal bar plot.
DataFrame.plot : Make plots of a DataFrame.
matplotlib.pyplot.bar : Make a bar plot with matplotlib.
Examples
--------
Basic plot.
.. plot::
:context: close-figs
>>> df = pd.DataFrame({'lab':['A', 'B', 'C'], 'val':[10, 30, 20]})
>>> ax = df.plot.bar(x='lab', y='val', rot=0)
Plot a whole dataframe to a bar plot. Each column is assigned a
distinct color, and each row is nested in a group along the
horizontal axis.
.. plot::
:context: close-figs
>>> speed = [0.1, 17.5, 40, 48, 52, 69, 88]
>>> lifespan = [2, 8, 70, 1.5, 25, 12, 28]
>>> index = ['snail', 'pig', 'elephant',
... 'rabbit', 'giraffe', 'coyote', 'horse']
>>> df = pd.DataFrame({'speed': speed,
... 'lifespan': lifespan}, index=index)
>>> ax = df.plot.bar(rot=0)
Instead of nesting, the figure can be split by column with
``subplots=True``. In this case, a :class:`numpy.ndarray` of
:class:`matplotlib.axes.Axes` are returned.
.. plot::
:context: close-figs
>>> axes = df.plot.bar(rot=0, subplots=True)
>>> axes[1].legend(loc=2) # doctest: +SKIP
Plot a single column.
.. plot::
:context: close-figs
>>> ax = df.plot.bar(y='speed', rot=0)
Plot only selected categories for the DataFrame.
.. plot::
:context: close-figs
>>> ax = df.plot.bar(x='lifespan', rot=0)
"""
return self(kind="bar", x=x, y=y, **kwargs)
def barh(self, x=None, y=None, **kwargs):
"""
Make a horizontal bar plot.
A horizontal bar plot is a plot that presents quantitative data with
rectangular bars with lengths proportional to the values that they
represent. A bar plot shows comparisons among discrete categories. One
axis of the plot shows the specific categories being compared, and the
other axis represents a measured value.
Parameters
----------
x : label or position, default DataFrame.index
Column to be used for categories.
y : label or position, default All numeric columns in dataframe
Columns to be plotted from the DataFrame.
**kwds
Keyword arguments to pass on to :meth:`DataFrame.plot`.
Returns
-------
:class:`matplotlib.axes.Axes` or numpy.ndarray of them
See Also
--------
DataFrame.plot.bar: Vertical bar plot.
DataFrame.plot : Make plots of DataFrame using matplotlib.
matplotlib.axes.Axes.bar : Plot a vertical bar plot using matplotlib.
Examples
--------
Basic example
.. plot::
:context: close-figs
>>> df = pd.DataFrame({'lab':['A', 'B', 'C'], 'val':[10, 30, 20]})
>>> ax = df.plot.barh(x='lab', y='val')
Plot a whole DataFrame to a horizontal bar plot
.. plot::
:context: close-figs
>>> speed = [0.1, 17.5, 40, 48, 52, 69, 88]
>>> lifespan = [2, 8, 70, 1.5, 25, 12, 28]
>>> index = ['snail', 'pig', 'elephant',
... 'rabbit', 'giraffe', 'coyote', 'horse']
>>> df = pd.DataFrame({'speed': speed,
... 'lifespan': lifespan}, index=index)
>>> ax = df.plot.barh()
Plot a column of the DataFrame to a horizontal bar plot
.. plot::
:context: close-figs
>>> speed = [0.1, 17.5, 40, 48, 52, 69, 88]
>>> lifespan = [2, 8, 70, 1.5, 25, 12, 28]
>>> index = ['snail', 'pig', 'elephant',
... 'rabbit', 'giraffe', 'coyote', 'horse']
>>> df = pd.DataFrame({'speed': speed,
... 'lifespan': lifespan}, index=index)
>>> ax = df.plot.barh(y='speed')
Plot DataFrame versus the desired column
.. plot::
:context: close-figs
>>> speed = [0.1, 17.5, 40, 48, 52, 69, 88]
>>> lifespan = [2, 8, 70, 1.5, 25, 12, 28]
>>> index = ['snail', 'pig', 'elephant',
... 'rabbit', 'giraffe', 'coyote', 'horse']
>>> df = pd.DataFrame({'speed': speed,
... 'lifespan': lifespan}, index=index)
>>> ax = df.plot.barh(x='lifespan')
"""
return self(kind="barh", x=x, y=y, **kwargs)
def box(self, by=None, **kwargs):
r"""
Make a box plot of the DataFrame columns.
A box plot is a method for graphically depicting groups of numerical
data through their quartiles.
The box extends from the Q1 to Q3 quartile values of the data,
with a line at the median (Q2). The whiskers extend from the edges
of box to show the range of the data. The position of the whiskers
is set by default to 1.5*IQR (IQR = Q3 - Q1) from the edges of the
box. Outlier points are those past the end of the whiskers.
For further details see Wikipedia's
entry for `boxplot <https://en.wikipedia.org/wiki/Box_plot>`__.
A consideration when using this chart is that the box and the whiskers
can overlap, which is very common when plotting small sets of data.
Parameters
----------
by : string or sequence
Column in the DataFrame to group by.
**kwds : optional
Additional keywords are documented in
:meth:`DataFrame.plot`.
Returns
-------
:class:`matplotlib.axes.Axes` or numpy.ndarray of them
See Also
--------
DataFrame.boxplot: Another method to draw a box plot.
Series.plot.box: Draw a box plot from a Series object.
matplotlib.pyplot.boxplot: Draw a box plot in matplotlib.
Examples
--------
Draw a box plot from a DataFrame with four columns of randomly
generated data.
.. plot::
:context: close-figs
>>> data = np.random.randn(25, 4)
>>> df = pd.DataFrame(data, columns=list('ABCD'))
>>> ax = df.plot.box()
"""
return self(kind="box", by=by, **kwargs)
def hist(self, by=None, bins=10, **kwargs):
"""
Draw one histogram of the DataFrame's columns.
A histogram is a representation of the distribution of data.
This function groups the values of all given Series in the DataFrame
into bins and draws all bins in one :class:`matplotlib.axes.Axes`.
This is useful when the DataFrame's Series are in a similar scale.
Parameters
----------
by : str or sequence, optional
Column in the DataFrame to group by.
bins : int, default 10
Number of histogram bins to be used.
**kwds
Additional keyword arguments are documented in
:meth:`DataFrame.plot`.
Returns
-------
class:`matplotlib.AxesSubplot`
Return a histogram plot.
See Also
--------
DataFrame.hist : Draw histograms per DataFrame's Series.
Series.hist : Draw a histogram with Series' data.
Examples
--------
When we draw a dice 6000 times, we expect to get each value around 1000
times. But when we draw two dices and sum the result, the distribution
is going to be quite different. A histogram illustrates those
distributions.
.. plot::
:context: close-figs
>>> df = pd.DataFrame(
... np.random.randint(1, 7, 6000),
... columns = ['one'])
>>> df['two'] = df['one'] + np.random.randint(1, 7, 6000)
>>> ax = df.plot.hist(bins=12, alpha=0.5)
"""
return self(kind="hist", by=by, bins=bins, **kwargs)
def kde(self, bw_method=None, ind=None, **kwargs):
"""
Generate 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
bandwidth determination.
.. _kernel density estimation:
https://en.wikipedia.org/wiki/Kernel_density_estimation
Parameters
----------
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 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
Additional keyword arguments are documented in
:meth:`pandas.%(this-datatype)s.plot`.
Returns
-------
matplotlib.axes.Axes or numpy.ndarray of them
See Also
--------
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 its PDF 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])
>>> ax = s.plot.kde()
A scalar bandwidth can be specified. Using a small bandwidth value can
lead to over-fitting, while using a large bandwidth value may result
in under-fitting:
.. plot::
:context: close-figs
>>> ax = s.plot.kde(bw_method=0.3)
.. plot::
:context: close-figs
>>> ax = s.plot.kde(bw_method=3)
Finally, the `ind` parameter determines the evaluation points for the
plot of the estimated PDF:
.. plot::
:context: close-figs
>>> ax = s.plot.kde(ind=[1, 2, 3, 4, 5])
For DataFrame, it works in the same way:
.. plot::
:context: close-figs
>>> df = pd.DataFrame({
... 'x': [1, 2, 2.5, 3, 3.5, 4, 5],
... 'y': [4, 4, 4.5, 5, 5.5, 6, 6],
... })
>>> ax = df.plot.kde()
A scalar bandwidth can be specified. Using a small bandwidth value can
lead to over-fitting, while using a large bandwidth value may result
in under-fitting:
.. plot::
:context: close-figs
>>> ax = df.plot.kde(bw_method=0.3)
.. plot::
:context: close-figs
>>> ax = df.plot.kde(bw_method=3)
Finally, the `ind` parameter determines the evaluation points for the
plot of the estimated PDF:
.. plot::
:context: close-figs
>>> ax = df.plot.kde(ind=[1, 2, 3, 4, 5, 6])
"""
return self(kind="kde", bw_method=bw_method, ind=ind, **kwargs)
density = kde
def area(self, x=None, y=None, **kwargs):
"""
Draw a stacked area plot.
An area plot displays quantitative data visually.
This function wraps the matplotlib area function.
Parameters
----------
x : label or position, optional
Coordinates for the X axis. By default uses the index.
y : label or position, optional
Column to plot. By default uses all columns.
stacked : bool, default True
Area plots are stacked by default. Set to False to create a
unstacked plot.
**kwds : optional
Additional keyword arguments are documented in
:meth:`DataFrame.plot`.
Returns
-------
matplotlib.axes.Axes or numpy.ndarray
Area plot, or array of area plots if subplots is True.
See Also
--------
DataFrame.plot : Make plots of DataFrame using matplotlib / pylab.
Examples
--------
Draw an area plot based on basic business metrics:
.. plot::
:context: close-figs
>>> df = pd.DataFrame({
... 'sales': [3, 2, 3, 9, 10, 6],
... 'signups': [5, 5, 6, 12, 14, 13],
... 'visits': [20, 42, 28, 62, 81, 50],
... }, index=pd.date_range(start='2018/01/01', end='2018/07/01',
... freq='M'))
>>> ax = df.plot.area()
Area plots are stacked by default. To produce an unstacked plot,
pass ``stacked=False``:
.. plot::
:context: close-figs
>>> ax = df.plot.area(stacked=False)
Draw an area plot for a single column:
.. plot::
:context: close-figs
>>> ax = df.plot.area(y='sales')
Draw with a different `x`:
.. plot::
:context: close-figs
>>> df = pd.DataFrame({
... 'sales': [3, 2, 3],
... 'visits': [20, 42, 28],
... 'day': [1, 2, 3],
... })
>>> ax = df.plot.area(x='day')
"""
return self(kind="area", x=x, y=y, **kwargs)
def pie(self, **kwargs):
"""
Generate a pie plot.
A pie plot is a proportional representation of the numerical data in a
column. This function wraps :meth:`matplotlib.pyplot.pie` for the
specified column. If no column reference is passed and
``subplots=True`` a pie plot is drawn for each numerical column
independently.
Parameters
----------
y : int or label, optional
Label or position of the column to plot.
If not provided, ``subplots=True`` argument must be passed.
**kwds
Keyword arguments to pass on to :meth:`DataFrame.plot`.
Returns
-------
matplotlib.axes.Axes or np.ndarray of them
A NumPy array is returned when `subplots` is True.
See Also
--------
Series.plot.pie : Generate a pie plot for a Series.
DataFrame.plot : Make plots of a DataFrame.
Examples
--------
In the example below we have a DataFrame with the information about
planet's mass and radius. We pass the the 'mass' column to the
pie function to get a pie plot.
.. plot::
:context: close-figs
>>> df = pd.DataFrame({'mass': [0.330, 4.87 , 5.97],
... 'radius': [2439.7, 6051.8, 6378.1]},
... index=['Mercury', 'Venus', 'Earth'])
>>> plot = df.plot.pie(y='mass', figsize=(5, 5))
.. plot::
:context: close-figs
>>> plot = df.plot.pie(subplots=True, figsize=(6, 3))
"""
if (
isinstance(self._parent, ABCDataFrame)
and kwargs.get("y", None) is None
and not kwargs.get("subplots", False)
):
raise ValueError("pie requires either y column or 'subplots=True'")
return self(kind="pie", **kwargs)
def scatter(self, x, y, s=None, c=None, **kwargs):
"""
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 : 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
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
instance ['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:`DataFrame.plot`.
Returns
-------
: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, s=s, c=c, **kwargs)
def hexbin(self, x, y, C=None, reduce_C_function=None, gridsize=None, **kwargs):
"""
Generate a hexagonal binning plot.
Generate a hexagonal binning plot of `x` versus `y`. If `C` is `None`
(the default), this is a histogram of the number of occurrences
of the observations at ``(x[i], y[i])``.
If `C` is specified, specifies values at given coordinates
``(x[i], y[i])``. These values are accumulated for each hexagonal
bin and then reduced according to `reduce_C_function`,
having as default the NumPy's mean function (:meth:`numpy.mean`).
(If `C` is specified, it must also be a 1-D sequence
of the same length as `x` and `y`, or a column label.)
Parameters
----------
x : int or str
The column label or position for x points.
y : int or str
The column label or position for y points.
C : int or str, optional
The column label or position for the value of `(x, y)` point.
reduce_C_function : callable, default `np.mean`
Function of one argument that reduces all the values in a bin to
a single number (e.g. `np.mean`, `np.max`, `np.sum`, `np.std`).
gridsize : int or tuple of (int, int), default 100
The number of hexagons in the x-direction.
The corresponding number of hexagons in the y-direction is
chosen in a way that the hexagons are approximately regular.
Alternatively, gridsize can be a tuple with two elements
specifying the number of hexagons in the x-direction and the
y-direction.
**kwds
Additional keyword arguments are documented in
:meth:`DataFrame.plot`.
Returns
-------
matplotlib.AxesSubplot
The matplotlib ``Axes`` on which the hexbin is plotted.
See Also
--------
DataFrame.plot : Make plots of a DataFrame.
matplotlib.pyplot.hexbin : Hexagonal binning plot using matplotlib,
the matplotlib function that is used under the hood.
Examples
--------
The following examples are generated with random data from
a normal distribution.
.. plot::
:context: close-figs
>>> n = 10000
>>> df = pd.DataFrame({'x': np.random.randn(n),
... 'y': np.random.randn(n)})
>>> ax = df.plot.hexbin(x='x', y='y', gridsize=20)
The next example uses `C` and `np.sum` as `reduce_C_function`.
Note that `'observations'` values ranges from 1 to 5 but the result
plot shows values up to more than 25. This is because of the
`reduce_C_function`.
.. plot::
:context: close-figs
>>> n = 500
>>> df = pd.DataFrame({
... 'coord_x': np.random.uniform(-3, 3, size=n),
... 'coord_y': np.random.uniform(30, 50, size=n),
... 'observations': np.random.randint(1,5, size=n)
... })
>>> ax = df.plot.hexbin(x='coord_x',
... y='coord_y',
... C='observations',
... reduce_C_function=np.sum,
... gridsize=10,
... cmap="viridis")
"""
if reduce_C_function is not None:
kwargs["reduce_C_function"] = reduce_C_function
if gridsize is not None:
kwargs["gridsize"] = gridsize
return self(kind="hexbin", x=x, y=y, C=C, **kwargs)
_backends = {}
def _find_backend(backend: str):
"""
Find a pandas plotting backend>
Parameters
----------
backend : str
The identifier for the backend. Either an entrypoint item registered
with pkg_resources, or a module name.
Notes
-----
Modifies _backends with imported backends as a side effect.
Returns
-------
types.ModuleType
The imported backend.
"""
import pkg_resources # Delay import for performance.
for entry_point in pkg_resources.iter_entry_points("pandas_plotting_backends"):
if entry_point.name == "matplotlib":
# matplotlib is an optional dependency. When
# missing, this would raise.
continue
_backends[entry_point.name] = entry_point.load()
try:
return _backends[backend]
except KeyError:
# Fall back to unregisted, module name approach.
try:
module = importlib.import_module(backend)
except ImportError:
# We re-raise later on.
pass
else:
_backends[backend] = module
return module
raise ValueError("No backend {}".format(backend))
def _get_plot_backend(backend=None):
"""
Return the plotting backend to use (e.g. `pandas.plotting._matplotlib`).
The plotting system of pandas has been using matplotlib, but the idea here
is that it can also work with other third-party backends. In the future,
this function will return the backend from a pandas option, and all the
rest of the code in this file will use the backend specified there for the
plotting.
The backend is imported lazily, as matplotlib is a soft dependency, and
pandas can be used without it being installed.
"""
backend = backend or pandas.get_option("plotting.backend")
if backend == "matplotlib":
# Because matplotlib is an optional dependency and first-party backend,
# we need to attempt an import here to raise an ImportError if needed.
import pandas.plotting._matplotlib as module
_backends["matplotlib"] = module
if backend in _backends:
return _backends[backend]
module = _find_backend(backend)
_backends[backend] = module
return module