| library(raster) | |
| library(sf) | |
| library(viridis) | |
| library(cartography) | |
| library(tanaka) | |
| temp <- tempfile() | |
| data_url <- "http://cidportal.jrc.ec.europa.eu/ftp/jrc-opendata/GHSL/GHS_POP_GPW4_GLOBE_R2015A/GHS_POP_GPW42015_GLOBE_R2015A_54009_1k/V1-0/GHS_POP_GPW42015_GLOBE_R2015A_54009_1k_v1_0.zip" | |
| download.file(data_url, temp) | |
| unzip(temp, exdir = "pop") | |
| pop2015 <- raster("pop/GHS_POP_GPW42015_GLOBE_R2015A_54009_1k_v1_0/GHS_POP_GPW42015_GLOBE_R2015A_54009_1k_v1_0.tif") | |
| center <- st_as_sf(data.frame(x=425483.8, y=5608290), | |
| coords=(c("x","y")), crs = st_crs(pop2015)) | |
| center <- st_buffer(center, dist = 800000) | |
| ras <- crop(pop2015, st_bbox(center)[c(1,3,2,4)]) | |
| mat <- focalWeight(x = ras, d = c(10000), type = "Gauss") | |
| rassmooth <- focal(x = ras, w = mat, fun = sum, pad = TRUE, padValue = 30) | |
| bks <- c(0,25,50,100,250,500,750,1000,1750,2500,5000, 7500,10000) | |
| png(filename = "circle.png", width = 800, height = 700, res = 100) | |
| par(mar = c(0,0,1.2,0)) | |
| tanaka(x = rassmooth, | |
| breaks = bks, | |
| mask = center, | |
| col = inferno(12),shift = 2500, | |
| legend.pos = "topleft", | |
| legend.title = "Inhabitants\nper km2") | |
| plot(st_geometry(center), add = T, border = "white", lwd = 6) | |
| layoutLayer(title = "Smoothed Population Density", | |
| author = 'Data : European Commission, Joint Research Centre (JRC); Columbia University, CIESIN (2015): GHS population grid, derived from GPW4.', | |
| sources = 'T. Giraud, 2019', scale = F, frame = F, tabtitle = TRUE) | |
| text(-374516.2 ,6408290.0, "Gaussian smoothing, sigma = 10km", adj = 0, font = 3, cex = .8 ) | |
| dev.off() |
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