https://github.com/cj-holmes/split-polygon-art
Documenting code to recreate art
https://github.com/cj-holmes/split-polygon-art
Last synced: 14 days ago
JSON representation
Documenting code to recreate art
- Host: GitHub
- URL: https://github.com/cj-holmes/split-polygon-art
- Owner: cj-holmes
- Created: 2023-06-11T20:04:56.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2023-06-11T20:06:49.000Z (over 2 years ago)
- Last Synced: 2024-07-18T08:44:50.699Z (over 1 year ago)
- Size: 2.16 MB
- Stars: 17
- Watchers: 2
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: README.Rmd
Awesome Lists containing this project
- awesome-ggplot2 - split polygon art
README
---
output: github_document
editor_options:
chunk_output_type: console
---
```{r, include = FALSE}
knitr::opts_chunk$set(
collapse = TRUE,
comment = "#>",
fig.width=5,
fig.height=5,
out.width = "65%",
dpi = 600
)
```
# split polygon art
## Intro
* Documenting my attempt at recreating the art I saw in [this tweet](https://twitter.com/mattdesl/status/1655857548808028161?s=20) with R.
* Then trying to further develop the idea
* This code is not written for speed or efficiency - using spatial libraries is certainly overkill, but it's the first way I prototyped the code and I haven't felt the need to go back and change it!
```{r warning=FALSE, message=FALSE}
library(tidyverse)
library(sf)
library(lwgeom)
library(wesanderson)
```
## Function
* Psuedo code for function
* Compute the (x,y) vertices of a regular polygon by rotating a line of length `radius` through equal angle steps about the point (`ox`, `oy`)
* Convert the vertices to an `{sf}` POLYGON
* Compute a random point inside the polygon if `px` and `py` is not provided
* Create an `{sf}` MULTILINESTRING containing a line from the point (px, py) to each vertex of the regular polygon
* Use the MULTILINESTRINGS to plit the regular polygon into sub polygons
```{r}
#' Return the {sf} polygons
#'
#' @param n_sides number of sides of regular polygon
#' @param offset_degrees offset angle for orientation of regular polygon
#' @param ox origin of regular polygon x coordinate
#' @param oy origin of regular polygon y coordinate
#' @param radius radius of or regular polygon (distance from origin to polygon vertices)
#' @param px origin point for the splitting lines x coordinate
#' @param py origin point for the splitting lines y coordinate
split_poly <- function(n_sides, offset_degrees, ox, oy, radius, px = NULL, py = NULL){
# Create polygon angles and vertex xy coords
a_step <- (2*pi)/n_sides
a <- seq(pi/2 + offset_degrees*(pi/180), by = a_step, l = n_sides)
x <- ox + cos(a) * radius
y <- oy + sin(a) * radius
# Create POLYGON
# Close polygon by making the last point the same as the first point
shape_polygon <- st_polygon(x = list(matrix(c(c(x, x[1]), c(y, y[1])), ncol = 2)))
# Compute a random point inside the polygon if no px or py is provided
if(is.null(px) || is.null(py)){
p_xy <- st_coordinates(st_sample(shape_polygon, 1))
px <- p_xy[1,1]
py <- p_xy[1,2]}
# Create MULTILINESTRING from each polygon vertex to the random point
lines <-
st_multilinestring(
lapply(
X = seq_along(a),
FUN = function(b) matrix(c(c(x[b], px), c(y[b], py)), ncol = 2)))
# Split the polygon based on the MULTILINESTRING
lwgeom::st_split(shape_polygon, lines) |> st_collection_extract("POLYGON")}
```
## Explore some different setups
* Create uniform square grid of x and y coordinates for the regular polygon centers
* Add values for the regular polygon number of sides, offset and radius against each grid point
* Run `split_poly()` on each point
* Assign a colour to each if the sub polygons created from each regular polygon
* Use the `wesanderson` palette `Zissou1`
* Plot the result
```{r}
set.seed(1)
crossing(ox = 1:5, oy = 1:5) |>
mutate(
n_sides = 4,
offset_degrees = 45,
radius = 0.55,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(col = sample(wes_palettes$Zissou1, size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = NA)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
```
* Choose colours from any of the `wesanderson` palettes
```{r}
set.seed(4)
crossing(ox = 1:5, oy = 1:5) |>
mutate(
n_sides = 4,
offset_degrees = 45,
radius = 0.55,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(col = sample(unlist(wes_palettes), size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = NA)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
```
* Larger grid and vary the regular polygon radius value based on position
```{r}
set.seed(2)
crossing(ox = 1:10, oy = 1:10) |>
mutate(
n_sides = 4,
offset_degrees = 45,
radius = scales::rescale(sqrt(abs(ox - 5.5)^2 + abs(oy - 5.5)^2), c(0.5, 0.3)),
g = pmap(
.l =
list(
ox = ox,
oy = oy,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(col = sample(wes_palettes$Darjeeling2, size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = 1)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = sample(unlist(wes_palettes), 1)))
```
* Gradually change the offset angle across the image
```{r}
set.seed(1)
crossing(ox = 1:5, oy = 1:5) |>
mutate(
n_sides = 3,
offset_degrees = seq(0, 180, l = n()),
radius = 0.5,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(
a = st_area(g),
col = sample(wes_palettes$Rushmore, size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = 1)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
```
* Random integer (3:5) number of sides for regular polygons
```{r}
set.seed(1)
crossing(oy = 1:15, ox = 1:15) |>
mutate(
n_sides = sample(3:5, size = n(), replace = TRUE),
offset_degrees = runif(n(), 0, 360),
radius = scales::rescale(sqrt(abs(ox - 4)^2 + abs(oy - 4)^2), c(0.5, 0.1)),
g = pmap(
.l =
list(
ox = ox,
oy = oy,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(
a = st_area(g),
col = sample(wes_palettes$Moonrise3, size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = 1)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
```
* Use non integer number of sides
```{r}
set.seed(1)
crossing(oy = 1:7, ox = 1:7) |>
mutate(
n_sides = seq(3, 4, l = n()),
offset_degrees = seq(0, 90, l = n()),
radius = 0.45,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(
a = st_area(g),
col = sample(unlist(wes_palettes), size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = 1)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
```
* All shapes using the same px/py point
```{r}
set.seed(1)
crossing(oy = 1:19, ox = 1:19) |>
mutate(
n_sides = 4,
offset_degrees = 45,
radius = 0.45,
px = 10,
py = 10,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
px = px,
py = py,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(
a = st_area(g),
col = sample(unlist(wes_palettes), size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = NA)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
set.seed(1)
crossing(oy = 1:19, ox = 1:19) |>
mutate(
n_sides = 4,
offset_degrees = seq(0, 90, l=n()),
radius = 0.45,
px = 10,
py = 10,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
px = px,
py = py,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(
a = st_area(g),
col = sample(unlist(wes_palettes), size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = NA)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
set.seed(1)
crossing(oy = 1:7, ox = 1:7) |>
mutate(
n_sides = 4,
offset_degrees = 45,
radius = 0.45,
px = 3,
py = 3.2,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
px = px,
py = py,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(
a = st_area(g),
col = sample(unlist(wes_palettes), size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = 1)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
```
* Vary the px/py point across the shapes
```{r}
set.seed(1)
crossing(oy = 1:7, ox = 1:7) |>
mutate(
n_sides = 4,
offset_degrees = 45,
radius = 0.45,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
px = ox + scales::rescale(ox, to = c(-0.2, 0.2)),
py = oy + scales::rescale(oy, to = c(-0.2, 0.2)),
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(
a = st_area(g),
col = sample(wes_palettes$Zissou1, size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = 1)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
crossing(oy = 1:10, ox = 1:10) |>
mutate(
n_sides = 4,
offset_degrees = 45,
radius = 0.45,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
px = 5.5 + cos(seq(0, 2*pi, l= n()))*2,
py = 5.5 + sin(seq(0, 2*pi, l= n()))*2,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(
a = st_area(g),
col = sample(wes_palettes$Zissou1, size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = 1)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))+
theme_bw()
```
* Approximate circles with high number of regular polygon sides
* Move the px/py point and colour the sub polygons by their area
```{r}
set.seed(1)
crossing(oy = 1:7, ox = 1:7) |>
mutate(
n_sides = 100,
offset_degrees = 0,
radius = 0.45,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
px = ox + scales::rescale(ox, to = c(-0.2, 0.2)),
py = oy + scales::rescale(oy, to = c(-0.2, 0.2)),
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(a = st_area(g)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = a), col = NA)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
scale_fill_viridis_c(option = "mako")+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey5"))
```
* A nasty look at hexagons using `st_make_grid()`
```{r}
set.seed(1)
nx <- 10
ny <- 10
hex_centers <-
sf::st_make_grid(
x = st_polygon(list(matrix(c(0, 0, nx, nx, 0, 0, ny, ny, 0, 0), ncol = 2))),
n = c(nx, ny),
what = "centers",
square = FALSE,
flat_topped = FALSE) |>
st_coordinates() |>
as_tibble() |>
rename(ox = X, oy = Y)
hex_polys <-
sf::st_make_grid(
x = st_polygon(list(matrix(c(0, 0, nx, nx, 0, 0, ny, ny, 0, 0), ncol = 2))),
n = c(nx, ny),
square = FALSE,
flat_topped = FALSE)
f <- 1
hex_centers |>
mutate(
n_sides = 6,
offset_degrees = 0,
radius = (1/sqrt(3))*f,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(col = sample(wes_palettes |> unlist(), size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = NA) +
# geom_sf(data = hex_polys, fill = NA, col = 1) +
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
f <- 0.85
hex_centers |>
mutate(
n_sides = 6,
offset_degrees = seq(0, 45, l=n()),
radius = (1/sqrt(3))*f,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
px = 2,
py = 2,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(col = sample(wes_palettes |> unlist(), size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = NA) +
# geom_sf(data = hex_polys, fill = NA, col = 1) +
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
```
* Some additonal experimentation with triangles
```{r}
set.seed(4)
crossing(ox = 1:9, oy = 1:9) |>
mutate(
n_sides = 3,
offset_degrees = rep(c(0, 180), length.out = n()),
radius = 0.45,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(col = sample(unlist(wes_palettes), size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = 1)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
set.seed(4)
crossing(ox = 1:9, oy = 1:9) |>
mutate(
n_sides = 3,
offset_degrees = rep(c(0, 90, 180, 270), length.out = n()),
radius = 0.45,
g = pmap(
.l =
list(
ox = ox,
oy = oy,
n_sides = n_sides,
offset_degrees = offset_degrees,
radius = radius),
.f = split_poly)) |>
unnest(cols = g) |>
group_by(ox, oy) |>
mutate(col = sample(unlist(wes_palettes), size = n(), replace = FALSE)) |>
st_as_sf() |>
ggplot()+
geom_sf(aes(fill = I(col)), col = 1)+
scale_x_continuous(expand = expansion(add = c(1,1)))+
scale_y_continuous(expand = expansion(add = c(1,1)))+
theme_void()+
theme(
legend.position = "",
panel.background = element_rect(color = NA, fill = "grey95"))
```