Gradient

A gradient definition specifies a gradient color pattern. Vega-Lite supports either a linear gradient or a radial gradient.

For example:

{
  "gradient": "linear",
  "stops": [
    {"offset": 0.0, "color": "red"},
    {"offset": 0.5, "color": "white"},
    {"offset": 1.0, "color": "blue"}
  ]
}

Linear Gradient

A linear gradient interpolates colors along a line, from a starting point to an ending point. By default a linear gradient runs horizontally, from left to right. Use the x1, y1, x2, and y2 properties to configure the gradient direction. All coordinates are defined in a normalized [0, 1] coordinate space, relative to the bounding box of the item being colored.

Example: Gradient Area Plot

Setting the area plot’s color encoding to "linear" gradient value produces a gradient area plot

Radial Gradient

A radial gradient interpolates colors between two circles, from an inner circle boundary to an outer circle boundary. By default a radial gradient runs from the center point of the coordinate system (zero radius inner circle), out to the maximum extent (0.5 radius outer circle). Use the x1, y1, x2, and y2 properties to configure the inner and outer circle center points, and use the r1 and r2 properties to configure the circle radii. All coordinates are defined in a normalized [0, 1] coordinate space, relative to the bounding box of the item being colored. A value of 1 corresponds to the maximum extent of the bounding box (width or height, whichever is larger).

Gradient Stop

A gradient stop consists of a Color value and an offset progress fraction.