# Phyllotaxis By Shiny

Antonio, you don’t know what empathy is! (Cecilia, my beautiful wife)

Spirals are nice. In the wake of my previous post I have done a Shiny app to explore patterns generated by changing angle, shape and number of points of Fermat’s spiral equation. You can obtain an almost infinite number of images. This is just an example:

I like thinking in imaginary flowers. This is why I called this experiment Phyllotaxis.
More examples:

Just one comment about code: I did the Shiny in just one R file as this guy suggested me some time ago because of this post.

This is the code. Do your own imaginary flowers:

```library(shiny)
library(ggplot2)
CreatePlot = function (ang=pi*(3-sqrt(5)), nob=150, siz=15, alp=0.8, sha=16, col="black", bac="white") {
ggplot(data.frame(r=sqrt(1:nob), t=(1:nob)*ang*pi/180), aes(x=r*cos(t), y=r*sin(t)))+
geom_point(colour=col, alpha=alp, size=siz, shape=sha)+
scale_x_continuous(expand=c(0,0), limits=c(-sqrt(nob)*1.4, sqrt(nob)*1.4))+
scale_y_continuous(expand=c(0,0), limits=c(-sqrt(nob)*1.4, sqrt(nob)*1.4))+
theme(legend.position="none",
panel.background = element_rect(fill=bac),
panel.grid=element_blank(),
axis.ticks=element_blank(),
axis.title=element_blank(),
axis.text=element_blank())}
shinyApp(
ui = fluidPage(
titlePanel("Phyllotaxis by Shiny"),
fluidRow(
column(3,
wellPanel(
selectInput("col", label = "Colour of points:", choices = colors(), selected = "black"),
selectInput("bac", label = "Background colour:", choices = colors(), selected = "white"),
selectInput("sha", label = "Shape of points:",
choices = list("Empty squares" = 0, "Empty circles" = 1, "Empty triangles"=2,
"Crosses" = 3, "Blades"=4, "Empty diamonds"=5,
"Inverted empty triangles"=6, "Bladed squares"=7,
"Asterisks"=8, "Crosed diamonds"=9, "Crossed circles"=10,
"Stars"=11, "Cubes"=12, "Bladed circles"=13,
"Filled squares" = 15, "Filled circles" = 16, "Filled triangles"=17,
"Filled diamonds"=18), selected = 16),
sliderInput("ang", label = "Angle (degrees):", min = 0, max = 360, value = 180*(3-sqrt(5)), step = .05),
sliderInput("nob", label = "Number of points:", min = 1, max = 1500, value = 60, step = 1),
sliderInput("siz", label = "Size of points:", min = 1, max = 60, value = 10, step = 1),
sliderInput("alp", label = "Transparency:", min = 0, max = 1, value = .5, step = .01)
)
),
mainPanel(
plotOutput("Phyllotaxis")
)
)
),
server = function(input, output) {
output\$Phyllotaxis=renderPlot({
CreatePlot(ang=input\$ang, nob=input\$nob, siz=input\$siz, alp=input\$alp, sha=as.numeric(input\$sha), col=input\$col, bac=input\$bac)
}, height = 650, width = 650 )}
)
```

## 5 thoughts on “Phyllotaxis By Shiny”

1. csaternos says:

Nice. Modified it a bit and uploaded it to https://stocks.shinyapps.io/phylo for others to enjoy (split it into server.R and ui.R files, called shinyServer and shinyUI functions respectively).

1. Very nice – and yes, ‘phyllotaxis’ is a good name for these patterns