In jsta/gshhg:

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.path = "README-"
)

gshhg

Installation

You can install gshhg from github with:

# install.packages("devtools")
devtools::install_github("jsta/gshhg")

Usage

library(gshhg)

# Download raw data
gshhg_get(version = "2.3.7")

library(sf)

# intermediate
dt_i <- st_read(
  list.files(file.path(gshhg:::cache_path(), "2.3.7", "GSHHS_shp", "i"), 
             pattern = "L1.shp", full.names = TRUE, include.dirs = TRUE))

# low
dt_l <- st_read(
  list.files(file.path(gshhg:::cache_path(), "2.3.7", "GSHHS_shp", "l"), 
             pattern = "L1.shp", full.names = TRUE, include.dirs = TRUE))

# crude
dt_c <- st_read(
  list.files(file.path(gshhg:::cache_path(), "2.3.7", "GSHHS_shp", "c"), 
             pattern = "L1.shp", full.names = TRUE, include.dirs = TRUE))

bb <- st_sfc(st_polygon(list(rbind(c(-6.46, 49.696), 
                             c(-7.2, 58.768), 
                             c(1.9336, 58.7909), 
                             c(2.417, 50.18), 
                             c(-6.46, 49.696)))), crs = 4326)

get_within <- function(dt, bb){
  dt[sapply(st_within(dt, bb), 
                        function(x) length(x) > 0),]
}

dt_britain <- lapply(list(dt_i, dt_l, dt_c), 
                     function(x) get_within(x, bb))

par(mfrow = c(1, 3))
lapply(dt_britain, function(x) plot(st_geometry(x)))

What is the lake coverage like?

lake_f <- st_read(
  list.files(file.path(gshhg:::cache_path(), "2.3.7", "GSHHS_shp", "f"), 
             pattern = "L2.shp", full.names = TRUE, include.dirs = TRUE))

mapview::mapview(lake_f[which.min(lake_f$area),])

m <- mapview::mapview(lake_f[which.min(lake_f$area),])
mapview::mapshot(m, file = "smallest_lake.png")

References

See http://www.soest.hawaii.edu/pwessel/gshhg/

jsta/gshhg documentation built on Oct. 14, 2023, 12:57 a.m.