Module « matplotlib.pyplot »

Fonction stem - module matplotlib.pyplot

Signature de la fonction stem

def stem(*args, linefmt=None, markerfmt=None, basefmt=None, bottom=0, label=None, use_line_collection=True, orientation='vertical', data=None) 

Description

stem.__doc__

Create a stem plot.

A stem plot draws lines perpendicular to a baseline at each location
*locs* from the baseline to *heads*, and places a marker there. For
vertical stem plots (the default), the *locs* are *x* positions, and
the *heads* are *y* values. For horizontal stem plots, the *locs* are
*y* positions, and the *heads* are *x* values.

Call signature::

  stem([locs,] heads, linefmt=None, markerfmt=None, basefmt=None)

The *locs*-positions are optional. The formats may be provided either
as positional or as keyword-arguments.

Parameters
----------
locs : array-like, default: (0, 1, ..., len(heads) - 1)
    For vertical stem plots, the x-positions of the stems.
    For horizontal stem plots, the y-positions of the stems.

heads : array-like
    For vertical stem plots, the y-values of the stem heads.
    For horizontal stem plots, the x-values of the stem heads.

linefmt : str, optional
    A string defining the color and/or linestyle of the vertical lines:

    =========  =============
    Character  Line Style
    =========  =============
    ``'-'``    solid line
    ``'--'``   dashed line
    ``'-.'``   dash-dot line
    ``':'``    dotted line
    =========  =============

    Default: 'C0-', i.e. solid line with the first color of the color
    cycle.

    Note: Markers specified through this parameter (e.g. 'x') will be
    silently ignored (unless using ``use_line_collection=False``).
    Instead, markers should be specified using *markerfmt*.

markerfmt : str, optional
    A string defining the color and/or shape of the markers at the stem
    heads.  Default: 'C0o', i.e. filled circles with the first color of
    the color cycle.

basefmt : str, default: 'C3-' ('C2-' in classic mode)
    A format string defining the properties of the baseline.

orientation : str, default: 'vertical'
    If 'vertical', will produce a plot with stems oriented vertically,
    otherwise the stems will be oriented horizontally.

bottom : float, default: 0
    The y/x-position of the baseline (depending on orientation).

label : str, default: None
    The label to use for the stems in legends.

use_line_collection : bool, default: True
    If ``True``, store and plot the stem lines as a
    `~.collections.LineCollection` instead of individual lines, which
    significantly increases performance.  If ``False``, defaults to the
    old behavior of using a list of `.Line2D` objects.  This parameter
    may be deprecated in the future.

Returns
-------
`.StemContainer`
    The container may be treated like a tuple
    (*markerline*, *stemlines*, *baseline*)

Notes
-----
.. seealso::
    The MATLAB function
    `stem <https://www.mathworks.com/help/matlab/ref/stem.html>`_
    which inspired this method.

.. note::
    In addition to the above described arguments, this function can take
    a *data* keyword argument. If such a *data* argument is given,
    every other argument can also be string ``s``, which is
    interpreted as ``data[s]`` (unless this raises an exception).

    Objects passed as **data** must support item access (``data[s]``) and
    membership test (``s in data``).