Coördinatenreferentiesystemen
Georuimtelijke data visualiseren in R
Charlotte Wickham
Assistant Professor at Oregon State University
proj4string()
proj4string(countries_spdf)
"+proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0"
↑ Geschikt voor globale datasets ↑
proj4string(water)
"+proj=longlat +datum=NAD83 +no_defs +ellps=GRS80 +towgs84=0,0,0"
↑ Vaak gebruikt voor VS-datasets ↑
proj4string()
proj4string(nyc_tracts)
"+proj=longlat +datum=NAD83 +no_defs +ellps=GRS80 +towgs84=0,0,0"
proj4string(neighborhoods)
"+proj=lcc +lat_1=40.66666666666666 +lat_2=41.03333333333333
+lat_0=40.16666666666666 +lon_0=-74 +x_0=300000 +y_0=0 +datum=NAD83
+units=us-ft +no_defs +ellps=GRS80 +towgs84=0,0,0"
Lambert Conformal Conic-projectie
CRS instellen
x <- SpatialPoints(data.frame(-123.2620, 44.5646))
x
class : SpatialPoints
features : 1
extent : -123.262, -123.262, 44.5646, 44.5646 (xmin, xmax, ymin, ymax)
coord. ref. : NA
proj4string(x) <- "+proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0"
x
class : SpatialPoints
features : 1
extent : -123.262, -123.262, 44.5646, 44.5646 (xmin, xmax, ymin, ymax)
coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84 +towgs84=0,0,0
CRS transformeren
rgdal::spTransform(x, CRSobj, ...)
spTransform(x, "+proj=lcc +lat_1=40.66666666666666
+lat_2=41.03333333333333 +lat_0=40.16666666666666
+lon_0=-74 +x_0=300000 +y_0=0 +datum=NAD83
+units=us-ft +no_defs +ellps=GRS80 +towgs84=0,0,0")
CRS transformeren
rgdal::spTransform(x, CRSobj, ...)
spTransform(x, proj4string(neighborhoods))
class : SpatialPoints
features : 1
extent : -11214982, -11214982, 5127323, 5127323 (xmin, xmax, ymin, ymax)
coord. ref. : +proj=lcc +lat_1=40.66666666666666
+lat_2=41.03333333333333 +lat_0=40.16666666666666
+lon_0=-74 +x_0=300000 +y_0=0 +datum=NAD83
+units=us-ft +no_defs +ellps=GRS80 +towgs84=0,0,0
Laten we oefenen!
Georuimtelijke data visualiseren in R
