matplotlib.pyplot.fill_betweenx#

matplotlib.pyplot.fill_betweenx(y, x1, x2=0, where=None, step=None, interpolate=False, *, data=None, **kwargs)[source]#

Fill the area between two vertical curves.

The curves are defined by the points (y, x1) and (y, x2). This creates one or multiple polygons describing the filled area.

You may exclude some vertical sections from filling using where.

By default, the edges connect the given points directly. Use step if the filling should be a step function, i.e. constant in between y.

Parameters:

yarray-like

The y coordinates of the nodes defining the curves.

x1array-like or float

The x coordinates of the nodes defining the first curve.

x2array-like or float, default: 0

The x coordinates of the nodes defining the second curve.

wherearray-like of bool, optional

Define where to exclude some vertical regions from being filled. The filled regions are defined by the coordinates y[where]. More precisely, fill between y[i] and y[i+1] if where[i] and where[i+1]. Note that this definition implies that an isolated True value between two False values in where will not result in filling. Both sides of the True position remain unfilled due to the adjacent False values.

interpolatebool, default: False

This option is only relevant if where is used and the two curves are crossing each other.

Semantically, where is often used for x1 > x2 or similar. By default, the nodes of the polygon defining the filled region will only be placed at the positions in the y array. Such a polygon cannot describe the above semantics close to the intersection. The y-sections containing the intersection are simply clipped.

Setting interpolate to True will calculate the actual intersection point and extend the filled region up to this point.

step{'pre', 'post', 'mid'}, optional

Define step if the filling should be a step function, i.e. constant in between y. The value determines where the step will occur:

• 'pre': The x value is continued constantly to the left from every y position, i.e. the interval (y[i-1], y[i]] has the value x[i].

• 'post': The y value is continued constantly to the right from every y position, i.e. the interval [y[i], y[i+1]) has the value x[i].

• 'mid': Steps occur half-way between the y positions.

Returns:

FillBetweenPolyCollection

A FillBetweenPolyCollection containing the plotted polygons.

Other Parameters:

dataindexable object, optional

If given, the following parameters also accept a string s, which is interpreted as data[s] if s is a key in data:

y, x1, x2, where

**kwargs

All other keyword arguments are passed on to FillBetweenPolyCollection. They control the Polygon 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 and two offsets from the bottom left corner of the image
alpha	array-like or float or None
animated	bool
antialiased or aa or antialiaseds	bool or list of bools
array	array-like or None
capstyle	CapStyle or {'butt', 'projecting', 'round'}
clim	(vmin: float, vmax: float)
clip_box	BboxBase or None
clip_on	bool
clip_path	Patch or (Path, Transform) or None
cmap	Colormap or str or None
color	color or list of RGBA tuples
data	array-like
edgecolor or ec or edgecolors	color or list of color or 'face'
facecolor or facecolors or fc	color or list of color
figure	Figure or SubFigure
gid	str
hatch	{'/', '\', '|', '-', '+', 'x', 'o', 'O', '.', '*'}
hatch_linewidth	unknown
hatchcolor	color or list of color or 'edge'
in_layout	bool
joinstyle	JoinStyle or {'miter', 'round', 'bevel'}
label	object
linestyle or dashes or linestyles or ls	{'-', '--', '-.', ':', '', ...} or (offset, on-off-seq) or list thereof
linewidth or linewidths or lw	float or list of floats
mouseover	bool
norm	Normalize or str or None
offset_transform or transOffset	Transform
offsets	(N, 2) or (2,) array-like
path_effects	list of AbstractPathEffect
paths	list of array-like
picker	None or bool or float or callable
pickradius	float
rasterized	bool
sizes	numpy.ndarray or None
sketch_params	(scale: float, length: float, randomness: float)
snap	bool or None
transform	Transform
url	str
urls	list of str or None
verts	list of array-like
verts_and_codes	unknown
visible	bool
zorder	float

See also

fill_between

Fill between two sets of y-values.

fill_betweenx

Fill between two sets of x-values.

Notes

Note

This is the pyplot wrapper for axes.Axes.fill_betweenx.