Plot density of lines

library(scattermore)

Create histogram

histogram <- scatter_lines_histogram(matrix(rnorm(40000),ncol=4,byrow=F), xlim=c(-5,5), ylim=c(-5,5))
image(histogram)

Apply some kernels on histogram

blurred_histogram <- apply_kernel_histogram(histogram, radius=4)
image(blurred_histogram)

gauss_blurred_histogram <- apply_kernel_histogram(histogram, filter="gauss", radius=4)
image(gauss_blurred_histogram)

Colorize blurred histogram

rgbwt <- histogram_to_rgbwt(blurred_histogram)
raster <- rgba_int_to_raster(rgbwt_to_rgba_int(rgbwt))
plot(raster, interpolate=F)

Colorize blurred histogram with palette

v = c(255, 0, 0, 100, 0, 255, 0, 25, 0, 0, 255, 50, 0, 0, 0, 100)
palette = array(v, c(4, 4))

rgbwt <- histogram_to_rgbwt(blurred_histogram, RGBA=palette)
raster <- rgba_int_to_raster(rgbwt_to_rgba_int(rgbwt))
plot(raster, interpolate=F)