4 seed aRt

4.1 What is a seed?

"A random seed (or seed state, or just seed) is a number used to initialize a pseudorandom number generator."

4.2 flametree

Inspired by Danielle Navarro's aRt packages we illustrate, using art, what setting a random seed does.

## use
## devtools::install_github("djnavarro/flametree")
## to install
library(flametree)

To grow the flametree we use the flametree_grow() function which has an argument seed. Using this we can grow any number of unique flametrees!

## R release date = 29 February 2000
## so set seed = 20000229
flametree <- flametree_grow(seed = 20000229) 
flametree_plot(tree = flametree)  

## The year of lockdowns 2020
flametree <- flametree_grow(seed = 2020) 
flametree_plot(tree = flametree)

4.3 Thorns

What about thorn02?

## required packages
pkgs <- c("Rcpp","ggplot2","ggforce","voronise","dplyr","here")
for(i in 1:length(pkgs)) if(!require(pkgs[i])) install.packages(pkgs[i])
## This isn't a package so we source the code files from GitHub
## and create the directory structure the function expects
## .cpp file needed
dir.create("../source")
dir.create("../image")
download.file("https://raw.githubusercontent.com/djnavarro/thorn02/master/source/thorn_02.cpp",destfile = "../source/thorn_02.cpp")
devtools::source_url("https://raw.githubusercontent.com/djnavarro/thorn02/master/source/thorn_02.R")

The thorn02() function we've just sourced has one argument: seed.

## using the worst password in the world
thorn02(seed = 1234)
## glasses of wine I had last night
thorn02(seed = 3)
## R release date = 29 February 2000
## so set seed = 20000229
thorn02(seed = 20000229)