matplotlib.axes.Axes.fill_between¶

Axes.
fill_between
(self, x, y1, y2=0, where=None, interpolate=False, step=None, *, data=None, **kwargs)[source]¶ Fill the area between two horizontal curves.
The curves are defined by the points (x, y1) and (x, y2). This creates one or multiple polygons describing the filled area.
You may exclude some horizontal 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 x.
Parameters:  xarray (length N)
The x coordinates of the nodes defining the curves.
 y1array (length N) or scalar
The y coordinates of the nodes defining the first curve.
 y2array (length N) or scalar, optional, default: 0
The y coordinates of the nodes defining the second curve.
 wherearray of bool (length N), optional, default: None
Define where to exclude some horizontal regions from being filled. The filled regions are defined by the coordinates
x[where]
. More precisely, fill betweenx[i]
andx[i+1]
ifwhere[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, optional
This option is only relevant if where is used and the two curves are crossing each other.
Semantically, where is often used for y1 > y2 or similar. By default, the nodes of the polygon defining the filled region will only be placed at the positions in the x array. Such a polygon cannot describe the above semantics close to the intersection. The xsections 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 x. The value determines where the step will occur:
 'pre': The y value is continued constantly to the left from
every x position, i.e. the interval
(x[i1], x[i]]
has the valuey[i]
.  'post': The y value is continued constantly to the right from
every x position, i.e. the interval
[x[i], x[i+1])
has the valuey[i]
.  'mid': Steps occur halfway between the x positions.
 'pre': The y value is continued constantly to the left from
every x position, i.e. the interval
Returns: PolyCollection
A
PolyCollection
containing the plotted polygons.
Other Parameters:  **kwargs
All other keyword arguments are passed on to
PolyCollection
. They control thePolygon
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
float or None animated
bool antialiased
or aa or antialiasedsbool or sequence of bools array
ndarray capstyle
{'butt', 'round', 'projecting'} clim
(vmin: float, vmax: float) clip_box
Bbox
clip_on
bool clip_path
Patch or (Path, Transform) or None cmap
colormap or registered colormap name color
color or sequence of rgba tuples contains
callable edgecolor
or ec or edgecolorscolor or sequence of colors or 'face' facecolor
or facecolors or fccolor or sequence of colors figure
Figure
gid
str hatch
{'/', '\', '', '', '+', 'x', 'o', 'O', '.', '*'} in_layout
bool joinstyle
{'miter', 'round', 'bevel'} label
object linestyle
or dashes or linestyles or ls{'', '', '.', ':', '', (offset, onoffseq), ...} linewidth
or linewidths or lwfloat or sequence of floats norm
Normalize
offset_position
{'screen', 'data'} offsets
arraylike (N, 2) or (2,) path_effects
AbstractPathEffect
picker
None or bool or float or callable pickradius
unknown rasterized
bool or None sketch_params
(scale: float, length: float, randomness: float) snap
bool or None transform
Transform
url
str urls
List[str] or None visible
bool zorder
float
See also
fill_betweenx
 Fill between two sets of xvalues.
Notes
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 arguments with the following names: 'where', 'x', 'y1', 'y2'.
Objects passed as data must support item access (
data[<arg>]
) and membership test (<arg> in data
).