canvas_flow {aRtsy}

Draw A Flow Field

Description

This function draws flow fields on a canvas. The algorithm simulates the flow of points through a field of angles which can be set manually or generated from the predictions of a supervised learning method (i.e., knn, svm, random forest) trained on randomly generated data.

Usage

canvas_flow(
  colors,
  background = "#fafafa",
  lines = 500,
  lwd = 0.05,
  iterations = 100,
  stepmax = 0.01,
  outline = c("none", "circle", "square"),
  polar = FALSE,
  angles = NULL
)

Arguments

colors

a string or character vector specifying the color(s) used for the artwork.

background

a character specifying the color used for the background.

lines

the number of lines to draw.

lwd

expansion factor for the line width.

iterations

the maximum number of iterations for each line.

stepmax

the maximum proportion of the canvas covered in each iteration.

outline

character. Which outline to use for the artwork. Possible options are none (default), circle or square.

polar

logical. Whether to draw the flow field with polar coordinates.

angles

optional, a 200 x 200 matrix containing the angles in the flow field, or a character indicating the type of noise to use (svm, knn, rf, perlin, cubic, simplex, or worley). If NULL (the default), the noise type is chosen randomly.

Value

A ggplot object containing the artwork.

Author(s)

Koen Derks, [e-mail]

References

https://tylerxhobbs.com/essays/2020/flow-fields

See Also

colorPalette

Examples

set.seed(1)

# Simple example
canvas_flow(colors = colorPalette("dark2"))

# Outline example
canvas_flow(
  colors = colorPalette("vrolik1"), lines = 10000,
  outline = "circle", iterations = 10, angles = "svm"
)

# Polar example
canvas_flow(
  colors = colorPalette("vrolik2"), lines = 300,
  lwd = 0.5, polar = TRUE
)

# Advanced example
angles <- matrix(0, 200, 200)
angles[1:100, ] <- seq(from = 0, to = 2 * pi, length = 100)
angles[101:200, ] <- seq(from = 2 * pi, to = 0, length = 100)
angles <- angles + rnorm(200 * 200, sd = 0.1)
canvas_flow(
  colors = colorPalette("tuscany1"), background = "black",
  angles = angles, lwd = 0.4, lines = 1000, stepmax = 0.001
)