Heatmap on a globe Lesson #1

heatmapGlobey.Rmd

A recreation of http://gis.stackexchange.com/questions/152094/heatmap-on-globe-distortion-problems

```{r}
library(raster)
library(geosphere)
library(MASS)

r <- raster(extent(-180, 180, -90, 90), nrow = 256, ncol = 256)


nn <- 300
#x <- randomCoordinates(nn)
x <- cbind(runif(nn, -180, 180), runif(nn, -90, 90))
kde <- raster(kde2d(x[,1], x[,2], h = c(bandwidth.nrd(x[,1]), bandwidth.nrd(x[,2]))/5,  n = nrow(r), lims = c(xmin(r), xmax(r), ymin(r), ymax(r))))


library(rgl)
library(rglgris) ## devtools::install_github("mdsumner/rglgris")

## build a quadmesh from raster
b <- bgl(r)

## sphere
b$vb[1:3,] <- t(llh2xyz(t(b$vb[1:3,])))
scl <- function(x) (x  - min(x))/diff(range(x))
shade3d(b, col = rep(terrain.colors(25)[scl(values(kde)) * 24 + 1], each = 4))

```