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

See also

axhspan

for example plot and source code

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)
  

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

Property	Description
agg_filter	unknown
alpha	float (0.0 transparent through 1.0 opaque)
animated	[True | False]
antialiased or aa	[True | False]
axes	an Axes instance
bottom_margin	unknown
clip_box	a matplotlib.transforms.Bbox instance
clip_on	[True | False]
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 matplotlib.figure.Figure instance
fillstyle	[‘full’ | ‘left’ | ‘right’ | ‘bottom’ | ‘top’ | ‘none’]
gid	an id string
label	string or anything printable with ‘%s’ conversion.
left_margin	unknown
linestyle or ls	[‘solid’ | ‘dashed’, ‘dashdot’, ‘dotted’ | (offset, on-off-dash-seq) | '-' | '--' | '-.' | ':' | 'None' | ' ' | '']
linewidth or lw	float value in points
margins	unknown
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	unknown
picker	float distance in points or callable pick function fn(artist, event)
pickradius	float distance in points
rasterized	[True | False | None]
right_margin	unknown
sketch_params	unknown
snap	unknown
solid_capstyle	[‘butt’ | ‘round’ | ‘projecting’]
solid_joinstyle	[‘miter’ | ‘round’ | ‘bevel’]
top_margin	unknown
transform	a matplotlib.transforms.Transform instance
url	a url string
visible	[True | False]
xdata	1D array
ydata	1D array
zorder	any number