matplotlib.axes.Axes.errorbar

Axes.errorbar(x, y, yerr=None, xerr=None, fmt='', ecolor=None, elinewidth=None, capsize=None, barsabove=False, lolims=False, uplims=False, xlolims=False, xuplims=False, errorevery=1, capthick=None, *, data=None, **kwargs)[source]

Plot y versus x as lines and/or markers with attached errorbars.

x, y define the data locations, xerr, yerr define the errorbar sizes. By default, this draws the data markers/lines as well the errorbars. Use fmt='none' to draw errorbars without any data markers.

Parameters

x, yfloat or array-like

The data positions.

xerr, yerrfloat or array-like, shape(N,) or shape(2, N), optional

The errorbar sizes:

scalar: Symmetric +/- values for all data points.
shape(N,): Symmetric +/-values for each data point.
shape(2, N): Separate - and + values for each bar. First row contains the lower errors, the second row contains the upper errors.
None: No errorbar.

Note that all error arrays should have positive values.

See Different ways of specifying error bars for an example on the usage of xerr and yerr.

fmtstr, default: ''

The format for the data points / data lines. See plot for details.

Use 'none' (case insensitive) to plot errorbars without any data markers.

ecolorcolor, default: None

The color of the errorbar lines. If None, use the color of the line connecting the markers.

elinewidthfloat, default: None

The linewidth of the errorbar lines. If None, the linewidth of the current style is used.

capsizefloat, default: rcParams["errorbar.capsize"] (default: 0.0)

The length of the error bar caps in points.

capthickfloat, default: None

An alias to the keyword argument markeredgewidth (a.k.a. mew). This setting is a more sensible name for the property that controls the thickness of the error bar cap in points. For backwards compatibility, if mew or markeredgewidth are given, then they will over-ride capthick. This may change in future releases.

barsabovebool, default: False

If True, will plot the errorbars above the plot symbols. Default is below.

lolims, uplims, xlolims, xuplimsbool, default: False

These arguments can be used to indicate that a value gives only upper/lower limits. In that case a caret symbol is used to indicate this. lims-arguments may be scalars, or array-likes of the same length as xerr and yerr. To use limits with inverted axes, set_xlim or set_ylim must be called before errorbar(). Note the tricky parameter names: setting e.g. lolims to True means that the y-value is a lower limit of the True value, so, only an upward-pointing arrow will be drawn!

erroreveryint or (int, int), default: 1

draws error bars on a subset of the data. errorevery =N draws error bars on the points (x[::N], y[::N]). errorevery =(start, N) draws error bars on the points (x[start::N], y[start::N]). e.g. errorevery=(6, 3) adds error bars to the data at (x[6], x[9], x[12], x[15], ...). Used to avoid overlapping error bars when two series share x-axis values.

Returns

ErrorbarContainer

The container contains:

plotline: Line2D instance of x, y plot markers and/or line.
caplines: A tuple of Line2D instances of the error bar caps.
barlinecols: A tuple of LineCollection with the horizontal and vertical error ranges.

Other Parameters

dataindexable object, optional

If given, the following parameters also accept a string s, which is interpreted as data[s] (unless this raises an exception):

x, y, xerr, yerr

**kwargs

All other keyword arguments are passed on to the plot call drawing the markers. For example, this code makes big red squares with thick green edges:

x, y, yerr = rand(3, 10)
errorbar(x, y, yerr, marker='s', mfc='red',
         mec='green', ms=20, mew=4)

where mfc, mec, ms and mew are aliases for the longer property names, markerfacecolor, markeredgecolor, markersize and markeredgewidth.

Valid kwargs for the marker properties are Line2D properties:

Property	Description
`agg_filter`	a filter function, which takes a (m, n, 3) float array and a dpi value, and returns a (m, n, 3) array
`alpha`	scalar or None
`animated`	bool
`antialiased` or aa	bool
`clip_box`	`Bbox`
`clip_on`	bool
`clip_path`	Patch or (Path, Transform) or None
`color` or c	color
`dash_capstyle`	`CapStyle` or {'butt', 'projecting', 'round'}
`dash_joinstyle`	`JoinStyle` or {'miter', 'round', 'bevel'}
`dashes`	sequence of floats (on/off ink in points) or (None, None)
`data`	(2, N) array or two 1D arrays
`drawstyle` or ds	{'default', 'steps', 'steps-pre', 'steps-mid', 'steps-post'}, default: 'default'
`figure`	`Figure`
`fillstyle`	{'full', 'left', 'right', 'bottom', 'top', 'none'}
`gid`	str
`in_layout`	bool
`label`	object
`linestyle` or ls	{'-', '--', '-.', ':', '', (offset, on-off-seq), ...}
`linewidth` or lw	float
`marker`	marker style string, `Path` or `MarkerStyle`
`markeredgecolor` or mec	color
`markeredgewidth` or mew	float
`markerfacecolor` or mfc	color
`markerfacecoloralt` or mfcalt	color
`markersize` or ms	float
`markevery`	None or int or (int, int) or slice or list[int] or float or (float, float) or list[bool]
`path_effects`	`AbstractPathEffect`
`picker`	float or callable[[Artist, Event], tuple[bool, dict]]
`pickradius`	float
`rasterized`	bool
`sketch_params`	(scale: float, length: float, randomness: float)
`snap`	bool or None
`solid_capstyle`	`CapStyle` or {'butt', 'projecting', 'round'}
`solid_joinstyle`	`JoinStyle` or {'miter', 'round', 'bevel'}
`transform`	unknown
`url`	str
`visible`	bool
`xdata`	1D array
`ydata`	1D array
`zorder`	float