heatmap

Creates a heat map plot of a scalar field.

Syntax

• heatmap(f, ❨xmin, xmax[, δx]❩, ❨ymin, ymax[, δy]❩[, c[, m]])

  • f is a function D → ℝ where D ⊂ ℝ²

  • xmin, xmax, ymin, and ymax are real numbers

  • δx and δy are non-negative real numbers

  • c is a colour, a list of two or three colours, or a function [0, 1] → colours

  • m is a boolean

Description

The heatmap function creates a heat map plot of the scalar field f in the rectangular region [xmin, xmax] × [ymin, ymax] with a sampling distance of δx in the first dimension and δy in the second dimension.

The plot is shown in the current diagram and a reference to the plot is returned.

The c and m parameters control the colour scheme. The same algorithm is used for the MatrixPlot function; see that article for details.

Examples

D ≔ diagram("vector field");
sf ≔ heatmap((x, y) ↦ x^2 + y^2, ❨−10, 10❩, ❨−10, 10❩, '("white", "red"));
vf ≔ VectorField((x, y) ↦ ❨2⋅x, 2⋅y❩, ❨−10, 10❩, ❨−10, 10❩)

heatmap((x, y) ↦ sin(√(x^2 + y^2)), ❨−10, 10❩, ❨−10, 10❩, "red")

sf ≔ heatmap((x, y) ↦ sin(√(x^2 + y^2)), ❨−10, 10❩, ❨−10, 10❩, '("blue", "red"))

sf ≔ heatmap((x, y) ↦ sin(√(x^2 + y^2)), ❨−10, 10❩, ❨−10, 10❩, '("blue", "white", "red"))

sf ≔ heatmap((x, y) ↦ sin(√(x^2 + y^2)), ❨−10, 10❩, ❨−10, 10❩, x ↦ hsv(360⋅x, 1, 1))

See also

• VectorField

• MatrixPlot

• ComputePixmap