europe.R

# data from http://ec.europa.eu/eurostat/web/gisco/geodata/reference-data/population-distribution-demography/geostat
# Originally seen at http://spatial.ly/2014/08/population-lines/

# So, this blew up on both Reddit and Twitter. Two bugs fixed (southern Spain was a mess,
# and some countries where missing -- measure twice, submit once, damnit), and two silly superflous lines removed after
# @hadleywickham pointed that out. Also, switched from geom_segment to geom_line.

# The result of the code below can be seen at http://imgur.com/ob8c8ph

library(tidyverse)

read_csv('../data/geostat-2011/GEOSTAT_grid_POP_1K_2011_V2_0_1.csv') %>%
  rbind(read_csv('../data/geostat-2011/JRC-GHSL_AIT-grid-POP_1K_2011.csv') %>%
          mutate(TOT_P_CON_DT='')) %>%
  mutate(lat = as.numeric(gsub('.*N([0-9]+)[EW].*', '\\1', GRD_ID))/100,
         lng = as.numeric(gsub('.*[EW]([0-9]+)', '\\1', GRD_ID)) * ifelse(gsub('.*([EW]).*', '\\1', GRD_ID) == 'W', -1, 1) / 100) %>%
  filter(lng > 25, lng < 60) %>%
  group_by(lat=round(lat, 1), lng=round(lng, 1)) %>%
  summarize(value = sum(TOT_P, na.rm=TRUE))  %>%
  ungroup() %>%
  complete(lat, lng) %>%
  ggplot(aes(lng, lat + 5*(value/max(value, na.rm=TRUE)))) +
    geom_line(size=0.4, alpha=0.8, color='#5A3E37', aes(group=lat), na.rm=TRUE) +
    ggthemes::theme_map() +
    coord_equal(0.9)

ggsave('/tmp/europe.png', width=10, height=10)

May I ask the meaning of the strings, like '1kmN2689E4337'? Can these represent real geographic coordinates?