fill_between

Fill the band between two y-curves that share the same x values. The standard way to shade a confidence band around a curve.

Matplotlib: Axes.fill_between. Coordinates are forwarded as fill_between(x, y1, y2, ...).

Axes: rectangular (ax).

Coordinates

Key	Required	Meaning
x	yes	Shared x positions
y1	yes	Lower (or first) curve
y2	no	Upper (or second) curve; defaults to 0

Style

Key	Type	Purpose
facecolor / color	color	Fill color
edgecolor	color	Edge color
alpha	0–1	Opacity
hatch	string	Hatch pattern
where	array	Boolean mask selecting where to fill
label	string	Legend label
zorder	number	Draw order

Any other Axes.fill_between keyword is also accepted.

Example

- name: band
  data:
    - source: curve
      transform: [ {sortby: x} ]
  axes: ax
  method: fill_between
  coordinates:
    x:  {expr: x}
    y1: {expr: "y - sigma"}
    y2: {expr: "y + sigma"}
  style:
    facecolor: gray
    alpha: 0.3

Notes

• For a band between two x-curves at shared y values, use fill_betweenx.

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See also: Plot Methods index · fill_betweenx · fill