Besides the many negative aspects of going through a pandemic, there are also certain positive ones like having time to write short blog posts like this.
This one picks up a topic that was intensively discussed a couple of years ago on Wolfram’s page: Namely that the damped sine wave
f(t) = t sin(t)
can be used to draw a Christmas tree. Throw in some 3D animation using the R package rgl and the tree begins to become virtual reality…
Here is our version using just ten lines of R code:
library(rgl) t <- seq(0, 100, by = 0.7)^0.6 x <- t * c(sin(t), sin(t + pi)) y <- t * c(cos(t), cos(t + pi)) z <- -2 * c(t, t) color <- rep(c("darkgreen", "gold"), each = length(t)) open3d(windowRect = c(100, 100, 600, 600), zoom = 0.9) bg3d("black") spheres3d(x, y, z, radius = 0.3, color = color) # On screen (skip if export) play3d(spin3d(axis = c(0, 0, 1), rpm = 4)) # Export (requires 3rd party tool "ImageMagick" resp. magick-package) # movie3d(spin3d(axis = c(0, 0, 1), rpm = 4), duration = 30, dir = getwd())
Christian and me wish you a relaxing time over Christmas. Take care of the people you love and stay healthy and safe.
Code and animation can be found on github.