blocks_length.R

pacman::p_load(tidyverse,sf,sfnetworks,nngeo,tidygraph)
options(scipen = 10000)
outer = matrix(c(0,0,1000,0,1000,1000,0,1000,0,0),ncol=2, byrow=TRUE)
make_grid <- function(street_length){st_polygon(list(outer)) %>% 
    st_make_grid(street_length) %>% 
    st_segments() }
x <- 200
map_df(c(2,4,5,8,10,20),~make_grid(1000/.x) %>% 
         st_segmentize(20) %>% 
         st_segments() %>% 
         as_sfnetwork(directed = F) %E>% 
         distinct() %>% 
         st_network_cost() %>% 
         as.vector() %>% 
         data.frame() %>% 
         rename(x = 1) %>% 
         mutate(street_length = 1000/.x)) %>% 
  ggplot(aes(x =x,fill = factor(street_length))) + 
  # geom_density(alpha=.5)
  geom_histogram()
map_df(c(2,4,5,8,10,20),~make_grid(1000/.x) %>% 
         st_segmentize(20) %>% 
         st_segments() %>% 
         as_sfnetwork(directed = F) %E>% 
         distinct() %N>% 
         as_tibble() %>% 
         mutate(street_length = 1000/.x)) %>% 
  
  ggplot()+
  geom_sf() +
  facet_wrap(~street_length)