edzer

see https://github.com/r-spatial/sf/blob/master/demo/twitter.R

edzer

https://twitter.com/allison_horst/status/1071456081308614656

edzer

# from: https://github.com/Irosenthal/Floating_Forests/blob/master/scripts/demo_of_merge/demo_merge.R
# see https://twitter.com/jebyrnes/status/963279659868749825
# alt: indicates a stars+sf workflow alternative to sp+raster
###########
# Libraries
###########

library(sp)
library(rgdal)
library(rgeos)

edzer

require("sf")
require("dplyr")
require("hexbin")

# Linux libertine font "sf", converted to path with Inkscape,
# added points between existing points 2 times, then turned all segments into straight lines.
# Saved as SVG with absolute coordinates (Preferences > SVG Output > Path Data).
# Loaded coords from SVG source code, remove letters from start and end, and replace " " with ","
coords_f <- c(218.1169,163.46992,215.56952,177.96334,213.51976,189.84421,211.82546,200.33884,210.34442,210.67351,208.24728,226.35176,205.51032,243.54066,201.92029,259.27223,197.26391,270.57846,195.45112,272.90665,193.28288,274.70167,190.97247,275.85687,188.73314,276.26564,187.03291,276.03164,185.79476,275.38887,184.84097,274.42619,183.99382,273.23248,182.45947,271.13533,180.24976,269.10927,177.54243,267.58084,174.51519,266.97658,171.25987,267.58973,169.08867,269.18036,167.87718,271.37526,167.501,273.8012,168.44294,277.0032,171.48203,279.79643,176.93817,281.77214,185.13126,282.52154,191.01986,281.80176,196.83737,279.60686,202.29944,

edzer

library(openeo) # make the openEO api functions available to the user

eo = openeo_connect("http://.../api/v0", user = "edzer", passwd = "****") # auth
# R6 object with reference semantics / encapsulated OOP

eo$datasets() # list/describe data sets available:
# Sentinel2A-L1C
# Proba-V
# ...

edzer

library(stars)
library(sf)
geomatrix = system.file("tif/geomatrix.tif", package = "stars")
x = st_stars(geomatrix)
st_dimensions(x)
##   from to  offset delta                        geotransform
## x    1 20 1841002   1.5 1841000, 1.5, -5, 1144000, -5, -1.5
## y    1 20 1144003  -1.5 1841000, 1.5, -5, 1144000, -5, -1.5
##                                               refsys point values
## x +proj=utm +zone=11 +datum=WGS84 +units=m +no_defs   TRUE   NULL

edzer

> system.time(for(i in 1:100000){a <- st_as_sfc("POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))")})
   user  system elapsed 
 11.228   0.000  11.231 
> system.time(for(i in 1:100000){a <- wkt_coords("POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))")})
   user  system elapsed 
 33.340   0.000  33.349 

edzer

st_cast0 <- function(x, to, ...) UseMethod("st_cast0")

# see this figure:
# https://cloud.githubusercontent.com/assets/520851/21387553/5f1edcaa-c778-11e6-92d0-2d735e4c8e40.png
# columns start counting at 0:

which_col = function(cls) {
	switch(cls,
		POINT = 0,
		LINESTRING = 1,