matplotlib.axes.Axes.axhline

Axes.axhline(y=0, xmin=0, xmax=1, **kwargs)

Add a horizontal line across the axis.

Parameters:

y : scalar, optional, default: 0

y position in data coordinates of the horizontal line.

xmin : scalar, optional, default: 0

Should be between 0 and 1, 0 being the far left of the plot, 1 the far right of the plot.

xmax : scalar, optional, default: 1

Should be between 0 and 1, 0 being the far left of the plot, 1 the far right of the plot.

Returns:

Line2D

Other Parameters:  

**kwargs :

Valid kwargs are Line2D properties, with the exception of ‘transform’:

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	float (0.0 transparent through 1.0 opaque)
animated	bool
antialiased or aa	bool
clip_box	a Bbox instance
clip_on	bool
clip_path	[(Path, Transform) | Patch | None]
color or c	any matplotlib color
contains	a callable function
dash_capstyle	[‘butt’ | ‘round’ | ‘projecting’]
dash_joinstyle	[‘miter’ | ‘round’ | ‘bevel’]
dashes	sequence of on/off ink in points
drawstyle	[‘default’ | ‘steps’ | ‘steps-pre’ | ‘steps-mid’ | ‘steps-post’]
figure	a Figure instance
fillstyle	[‘full’ | ‘left’ | ‘right’ | ‘bottom’ | ‘top’ | ‘none’]
gid	an id string
label	object
linestyle or ls	[‘solid’ | ‘dashed’, ‘dashdot’, ‘dotted’ | (offset, on-off-dash-seq) | '-' | '--' | '-.' | ':' | 'None' | ' ' | '']
linewidth or lw	float value in points
marker	A valid marker style
markeredgecolor or mec	any matplotlib color
markeredgewidth or mew	float value in points
markerfacecolor or mfc	any matplotlib color
markerfacecoloralt or mfcalt	any matplotlib color
markersize or ms	float
markevery	[None | int | length-2 tuple of int | slice | list/array of int | float | length-2 tuple of float]
path_effects	AbstractPathEffect
picker	float distance in points or callable pick function fn(artist, event)
pickradius	float distance in points
rasterized	bool or None
sketch_params	(scale: float, length: float, randomness: float)
snap	bool or None
solid_capstyle	[‘butt’ | ‘round’ | ‘projecting’]
solid_joinstyle	[‘miter’ | ‘round’ | ‘bevel’]
transform	a matplotlib.transforms.Transform instance
url	a url string
visible	bool
xdata	1D array
ydata	1D array
zorder	float

See also

hlines

add horizontal lines in data coordinates

axhspan

add a horizontal span (rectangle) across the axis

Notes

kwargs are passed to Line2D and can be used to control the line properties.

Examples

• draw a thick red hline at ‘y’ = 0 that spans the xrange:

  >>> axhline(linewidth=4, color='r')
  

• draw a default hline at ‘y’ = 1 that spans the xrange:

  >>> axhline(y=1)
  

• draw a default hline at ‘y’ = .5 that spans the middle half of the xrange:

  >>> axhline(y=.5, xmin=0.25, xmax=0.75)