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Generate a radial string art pattern with triangular modules

Source: R/stradial.R
stradial.Rd

stradial() generates a radial string art pattern composed of triangular modules rotated around the origin. In each module, pegs are placed along the triangular boundary and connected according to an additive modular rule.

Usage

stradial(
  n = 18,
  k = 5,
  col = "blue",
  lwd = 1,
  plot = TRUE,
  show_points = TRUE,
  show_labels = FALSE,
  verbose = FALSE,
  m = 6,
  r = 1.2,
  spread = pi/5,
  rotate = 0,
  show_strings = TRUE,
  template = FALSE,
  point_col = "black",
  point_cex = 0.8,
  point_pch = 21,
  point_bg = "white",
  label_cex = 0.7,
  label_col = "black",
  border_col = "grey50",
  border_lwd = 1,
  bg = "white",
  main = NULL,
  show_center = TRUE,
  center_col = "black",
  center_cex = 0.9
)

Arguments

n

Integer. Number of pegs in each triangular module. Must be at least 3.

k

Integer. Additive modular step used inside each module. Must satisfy 1 <= k <= n - 1.

col

String color, or a vector of colors with length 1 or m, used to draw the string connections.

lwd

Positive number. Line width used to draw the strings.

plot

Logical. If TRUE, draws the figure.

show_points

Logical. If TRUE, draws the pegs.

show_labels

Logical. If TRUE, draws peg labels.

verbose

Logical. If TRUE, prints a short audit to the console.

m

Integer. Number of triangular modules.

r

Positive number. Distance from the origin to the two outer vertices of each triangular module.

spread

Positive number. Angular opening, in radians, of each module.

rotate

Numeric. Rotation angle in radians applied to the whole figure.

show_strings

Logical. If TRUE, draws the string connections.

template

Logical. If TRUE, draws only the peg template, without string connections. This is equivalent to setting show_strings = FALSE and show_points = TRUE.

point_col

Peg border color.

point_cex

Positive number. Peg size.

point_pch

Plotting symbol used for pegs.

point_bg

Peg background color when applicable.

label_cex

Positive number. Label size.

label_col

Label color.

border_col

Module border color.

border_lwd

Positive number. Module border line width.

bg

Plot background color.

main

Optional plot title. If NULL, no title is displayed.

show_center

Logical. If TRUE, highlights the origin.

center_col

Color used to highlight the origin.

center_cex

Positive number. Size of the highlighted origin.

Value

Invisibly returns a list of class stringart_result with:

pegs

A data.frame with columns index, x, y, module, and local_index.

connections

A data.frame with columns connection_index, from, to, x_from, y_from, x_to, y_to, length, module, local_from, local_to, and color.

total_length

Total string length.

audit

A character vector with audit information.

meta

A list with construction metadata.

Details

Each module is a triangle with vertices at the origin and at two outer points determined by r and spread. The base module is rotated m times around the origin.

Within each module, the local connection rule is:

to = ((from + k - 1) %% n) + 1.

This means that each local peg is connected to the peg k positions ahead, using modular indexing. The same local rule is applied independently to all modules.

Examples

stradial()


res <- stradial(plot = FALSE)
head(res$pegs)
#>   index         x           y module local_index
#> 1     1 0.0000000  0.00000000      1           1
#> 2     2 0.1659932 -0.05393447      1           2
#> 3     3 0.3319864 -0.10786893      1           3
#> 4     4 0.4979797 -0.16180340      1           4
#> 5     5 0.6639729 -0.21573787      1           5
#> 6     6 0.8299661 -0.26967233      1           6
head(res$connections)
#>   connection_index from to    x_from      y_from      x_to          y_to
#> 1                1    1  6 0.0000000  0.00000000 0.8299661 -2.696723e-01
#> 2                2    2  7 0.1659932 -0.05393447 0.9959593 -3.236068e-01
#> 3                3    3  8 0.3319864 -0.10786893 1.1412678 -3.490712e-01
#> 4                4    4  9 0.4979797 -0.16180340 1.1412678 -1.745356e-01
#> 5                5    5 10 0.6639729 -0.21573787 1.1412678 -1.387779e-16
#> 6                6    6 11 0.8299661 -0.26967233 1.1412678  1.745356e-01
#>      length module local_from local_to color
#> 1 0.8726780      1          1        6  blue
#> 2 0.8726780      1          2        7  blue
#> 3 0.8444613      1          3        8  blue
#> 4 0.6434142      1          4        9  blue
#> 5 0.5237874      1          5       10  blue
#> 6 0.5424292      1          6       11  blue
res$total_length
#> [1] 70.4474

stradial(n = 18, k = 5, m = 6, col = "steelblue", lwd = 0.8)

stradial(n = 12, k = 4, m = 5, show_points = TRUE, show_labels = TRUE)

stradial(template = TRUE)