rgdal: Bindings for the Geospatial Data Abstraction Library

地形・地質マッピング

> library(rgdal)

rgdal: version: 1.0-4, (SVN revision 548)
 Geospatial Data Abstraction Library extensions to R successfully loaded
 Loaded GDAL runtime: GDAL 1.11.2, released 2015/02/10
 Path to GDAL shared files: /Library/Frameworks/R.framework/Versions/3.2/Resources/library/rgdal/gdal
 Loaded PROJ.4 runtime: Rel. 4.9.1, 04 March 2015, [PJ_VERSION: 491]
 Path to PROJ.4 shared files: /Library/Frameworks/R.framework/Versions/3.2/Resources/library/rgdal/proj
 Linking to sp version: 1.1-1

> data("state")

バージョン: 1.0.4

関数名 概略
CRS-class Class "CRS" of coordinate reference system arguments
GDALDataset-class Class "GDALDataset"
GDALDriver-class Class "GDALDriver": GDAL Driver Object
GDALMajorObject-class Class "GDALMajorObject"
GDALRasterBand-class Class "GDALRasterBand"
GDALReadOnlyDataset-class Class "GDALReadOnlyDataset"
GDALReadOnlyDataset-methods subset methods for "GDALReadOnlyDataset"
GDALTransientDataset-class Class "GDALTransientDataset"
GDALcall Wrapper functions to allow more direct calling of rgdal C code
RGB2PCT Convert RGB three band to single band colour table
SGDF2PCT Convert RGB three band to single band colour table
SpatialGDAL-class Class "SpatialGDAL"
closeDataset-methods closeDataset methods
displayDataset Display a GDAL dataset
llgridlines Plot long-lat grid over projected data
make_EPSG Make a data frame of EPSG projection codes
nor2k Norwegian peaks over 2000m
projInfo List PROJ.4 tag information
project Projection of coordinate matrices
readGDAL Read/write between GDAL grid maps and Spatial objects
readOGR Read OGR vector maps into Spatial objects
showWKT Show Well-Known Text spatial reference system metadata
spTransform-methods Methods for Function spTransform for map projection and datum transformation in package "rgdal"
writeOGR Write spatial vector data using OGR

readOGR

Arguments

  • dsn... data source name
  • layer
  • verbose
  • p4s
  • stringsAsFactors
  • drop_unsupported_fields
  • input_field_name_encoding
  • pointDropZ
  • dropNULLGeometries
  • useC
  • disambiguateFIDs
  • addCommentsToPolygons
  • encoding
  • use_iconv
  • swapAxisOrder
  • require_geomType
  • integer64
  • x
  • ...
> system.file("vectors/Up.tab", package = "rgdal") %>% {
+   ogrInfo(dsn = ., layer = "Up")
+   readOGR(dsn = ., layer = "Up") %>% {
+      summary(.) %>% print()
+     plot(.)
+   }
+ }
> jp.map <- readOGR(dsn              = "https://gist.github.com/uribo/b09d642351c03dd975aa/raw/6cd2f7e70922b24f89b442c96c001dc3ab794317/japan_one_twenty_map.topojson", 
+                   layer            = "OGRGeoJSON", 
+                   stringsAsFactors = FALSE)

spTransform

> states <- data.frame(state.x77, state.center) %$% .[x > -121,]
> coordinates(states) <- c("x", "y")
> proj4string(states) <- CRS("+proj=longlat +ellps=clrk66")
> summary(states)

                Length                  Class                   Mode 
                    48 SpatialPointsDataFrame                     S4

> # plot(states)

> map.data <- geocode(c("Tokyo, Japan", "Osaka, Japan", "Sapporo, Japan"),
+         source = "google")
> map.data$name <- c("Tokyo", "Osaka", "Sapproro")
> jp.map %<>% fortify()
> jp.map.plot <- ggplot() + 
+   geom_map(data = jp.map,
+            map = jp.map,
+            aes(x = long, y = lat, group = group, map_id = id),
+            fill = "white",
+            color = "black",
+            size = 0.2) +
+   coord_map() +
+   theme_minimal()
> jp.map.plot +
+   geom_point(data = map.data, aes(x = lon, y = lat),
+              color = "red", size = 3) +
+   geom_text(data = map.data, aes(x = lon, y = lat, label = name),
+             vjust = -1)