You are reading documentation for the unreleased version of Matplotlib. Try searching for the released version of this page instead?
Applications are open for the 2018 John Hunter Matplotlib Summer Fellowship. Apply now!
Version 2.2.2.post1772+gd9240e24b
matplotlib
Fork me on GitHub

matplotlib.axes.Axes.stem

Axes.stem(*args, linefmt=None, markerfmt=None, basefmt=None, bottom=0, label=None, data=None)[source]

Create a stem plot.

A stem plot plots vertical lines at each x location from the baseline to y, and places a marker there.

Call signature:

stem([x,] y, linefmt=None, markerfmt=None, basefmt=None)

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

Parameters:
x : array-like, optional

The x-positions of the stems. Default: (0, 1, ..., len(y) - 1).

y : array-like

The y-values of the stem heads.

linefmt : str, optional

A string defining the properties of the vertical lines. Usually, this will be a color or a color and a linestyle:

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: While it is technically possible to specify valid formats other than color or color and linestyle (e.g. 'rx' or '-.'), this is beyond the intention of the method and will most likely not result in a reasonable reasonable plot.

markerfmt : str, optional

A string defining the properties of the markers at the stem heads. Default: 'C0o', i.e. filled circles with the first color of the color cycle.

basefmt : str, optional

A format string defining the properties of the baseline.

Default: 'C3-' ('C2-' in classic mode).

bottom : float, optional, default: 0

The y-position of the baseline.

label : str, optional, default: None

The label to use for the stems in legends.

Returns:
container : StemContainer

The container may be treated like a tuple (markerline, stemlines, baseline)

Notes

See also

The MATLAB function stem 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, the following arguments are replaced by data[<arg>]:

  • All positional and all keyword arguments.

Objects passed as data must support item access (data[<arg>]) and membership test (<arg> in data).