Shapefile の座標変換
geotools.rb を使って Shapefile データの座標変換をする方法をまとめてみます。
お題は、
というものです。行政界、というより行政区画データと言った方が正しいかもしれません。
このお題を解くために、geotools.rb のクラス Transform に以下のメソッドを追加しました。
Transform#transform(geom) | 引数で与えられた幾何オブジェクトを座標変換して返す |
材料
http://www.globalmap.org/download/kanni01.html から、地球地図日本バージョン 1.1 行政域 (行政区画のほうが良い名前かも) データ(http://www.globalmap.org/download/data/shp/1_1/bnda_1_1.zip)を入手しました。
アプリケーションコード実装
属性をコピーしないなら、こんな感じ:
require 'geotools' t = Geo::Transform.new( Geo::import_epsg_crs(4326), Geo::import_epsg_crs(2451)) Geo::Writer.open('ibaraki_2451.shp') do |w| Geo::Reader.foreach('bnda_1_1.shp', {:whitelist => 'nam'}) do |geom, attrs| next unless attrs['nam'] == 'IBARAKI' w.write(t.transform(geom), {}) end end
属性をコピーするなら、こんな感じ:
require 'geotools' t = Geo::Transform.new( Geo::import_epsg_crs(4326), Geo::import_epsg_crs(2451)) Geo::Writer.open('ibaraki_2451_attrs.shp') do |w| Geo::Reader.foreach('bnda_1_1.shp') do |geom, attrs| next unless attrs['nam'] == 'IBARAKI' w.write(t.transform(geom), attrs) end end
これで座標変換された Shapefile データ、ibaraki_2451(_attrs).shp が手に入ります。GeoTools を裸で使うのと比べ、ずいぶんシンプルにできたと思っています。
アプリケーションコード実行時間
実行時間はこの程度です:
$ time ruby proj.rb DEBUG: rjb primitive_conversion mode real 0m2.224s user 0m1.894s sys 0m0.246s $ time ruby proj_attrs.rb DEBUG: rjb primitive_conversion mode real 0m2.630s user 0m2.367s sys 0m0.246s
geotools.rb 実装
現時点の geotools.rb の実装はこのようになっています。
# this code is under development and subject to major change. require 'iconv' module Geo # Geo::Tools module, to include nesessary classes from Geotools module Tools QUALIFIED_NAMES = %w{java.lang.System java.lang.String java.lang.Integer java.lang.Double java.lang.Long java.io.File java.util.HashMap org.geotools.data.shapefile.ShapefileDataStore org.geotools.feature.AttributeTypeFactory org.geotools.feature.FeatureTypeBuilder org.geotools.feature.type.GeometricAttributeType com.vividsolutions.jts.io.WKTReader org.geotools.referencing.crs.EPSGCRSAuthorityFactory org.geotools.referencing.operation.DefaultCoordinateOperationFactory org.geotools.geometry.DirectPosition2D org.geotools.data.vpf.file.VPFFile org.geotools.data.vpf.VPFLibrary org.geotools.gce.geotiff.GeoTiffWriter org.geotools.coverage.grid.GridCoverageFactory com.vividsolutions.jts.geom.Envelope org.geotools.geometry.Envelope2D org.geotools.factory.Hints org.geotools.geometry.jts.JTS} begin require 'rjb' QUALIFIED_NAMES.each do |qn| sn = qn.split('.').last module_eval "#{sn} = Rjb::import('#{qn}')" end IMPLEMENTATION = 'rjb' rescue LoadError require 'java' QUALIFIED_NAMES.each do |qn| include_class qn end IMPLEMENTATION = 'java' end end # Geo module variables @@wkt_reader = nil @@epsg_crs_authority_factory = nil # Geo module 'good-wrapper' / 'Grossklasstum' classes class Reader if Tools::IMPLEMENTATION == 'java' print "DEBUG: jruby mode\n" def iterate while(@iter.hasNext) feat = @iter.next attrs = {} @attr_names.each do |attr_name| attrs[attr_name] = feat.getAttribute(attr_name) end yield feat.getDefaultGeometry, attrs end end else begin Rjb::primitive_conversion = true print "DEBUG: rjb primitive_conversion mode\n" def iterate while(@iter.hasNext) feat = @iter.next attrs = {} @attr_names.each do |attr_name| attr = feat.getAttribute(attr_name) attr = attr.toString if attr.getClass == Geo::Tools::String attrs[attr_name] = attr end yield feat.getDefaultGeometry, attrs end end rescue NoMethodError print "DEBUG: rjb conventional mode\n" def iterate while(@iter.hasNext) feat = @iter.next attrs = {} @attr_names.each do |attr_name| attr = feat.getAttribute(attr_name) if attr.getClass.equals(Tools::Integer) attr = attr.intValue elsif attr.getClass.equals(Tools::Double) attr = attr.doubleValue elsif attr.getClass.equals(Tools::String) if @sjis_workaround attr = Iconv.conv('UTF-8', 'Shift_JIS', attr.getBytes('iso-8859-1')) else attr = attr.toString end elsif attr.getClass.equals(Tools::Long) attr = attr.longValue end attrs[attr_name] = attr end yield feat.getDefaultGeometry, attrs end end end end # keys for options: :sjis_workaround (boolean), :whitelist (array) def Reader::foreach(shapefile, options = {}) r = Reader.new(shapefile, options) r.iterate do |geom, attrs| yield geom, attrs end r.close end def initialize(shapefile, options = {}) @sjis_workaround = options[:sjis_workaround] @sjis_workaround = false if @sjis_workaround == nil if(Tools::IMPLEMENTATION == 'java' && @sjis_workaround) raise "sjis_workaround for JRuby is not implemented." end store = Tools::ShapefileDataStore.new(Tools::File.new(shapefile).toURL) @iter = store.getFeatureSource.getFeatures.features feat_type = store.getFeatureSource.getSchema if options[:whitelist] == nil @attr_names = [] feat_type.getAttributeCount.times do |i| name = feat_type.getAttributeType(i).getName @attr_names << name unless name == 'the_geom' end else @attr_names = options[:whitelist] #TODO: whitelist checking necessary? end end def close @iter.close end end class Writer def Writer::open(shapefile) w = Writer.new(shapefile) yield w w.close end def initialize(shapefile) @shapefile = shapefile @writer = nil @first = true end def setup(geom, attrs) attrs.delete('the_geom') ftb = Tools::FeatureTypeBuilder.newInstance(@shapefile) attrs.each do |key, value| if value.methods.include?('_classname') attr_class = value.getClass elsif value.class == String attr_class = Tools::String elsif value.class == Fixnum attr_class = Tools::Integer elsif value.class == Float attr_class = Tools::Double else raise "attribute #{key} has unrecognizable class #{value.class}" end ftb.addType(Tools::AttributeTypeFactory.newAttributeType(key, attr_class)) end if geom.class == String geom = import_wkt_geometry(geom) end ftb.setDefaultGeometry(Tools::GeometricAttributeType.new('the_geom', geom.getClass, true, nil, nil, nil)) ft = ftb.getFeatureType store = Tools::ShapefileDataStore.new(Tools::File.new(@shapefile).toURL) store.createSchema(ft) @writer = store.getFeatureWriter(@shapefile, store.getFeatureSource(@shapefile).getTransaction) @first = false end private :setup def write(geom, attrs) setup(geom, attrs) if @first feat = @writer.next if geom.class == String geom = import_wkt_geometry(geom) end feat.setDefaultGeometry(geom) attrs.each do |key, value| feat.setAttribute(key, value) end @writer.write end def close @writer.close unless @writer == nil end end class Transform def initialize(src_crs, dst_crs) cof = Geo::Tools::DefaultCoordinateOperationFactory.new @co = cof.createOperation(src_crs, dst_crs) @mt = @co.getMathTransform end def transform(x, y) # z? r = Geo::Tools::DirectPosition2D.new @mt.transform(Geo::Tools::DirectPosition2D.new(x, y), r) return r.x, r.y end def transform(geom) Geo::Tools::JTS::transform(geom, @mt) end ## TODO: accessor to @mt or @co end # Geo module convenient methods def Geo::import_wkt_geometry(wkt) @@wkt_reader = Geo::Tools::WKTReader.new if @@wkt_reader == nil @@wkt_reader.read(wkt) end def Geo::import_epsg_crs(epsg_code) @@epsg_crs_authority_factory = Geo::Tools::EPSGCRSAuthorityFactory.new if @@epsg_crs_authority_factory == nil if epsg_code.class == Fixnum return @@epsg_crs_authority_factory.createCoordinateReferenceSystem("EPSG:#{epsg_code}") elsif epsg_code.class == String return @@epsg_crs_authority_factory.createCoordinateReferenceSystem(epsg_code) else raise "Geo::import_epsg_crs: can not handle epsg_code = #{epsg_code}" end end def dms2dec(d, m, s) d + m / 60.0 + s / 3600.0 end def dec2dms(dec) #TODO raise "not implemented." end end # ad hoc tests if __FILE__ == $0 ## TODO: better separate tests as unit tests. start_time = Time.now Geo::Writer.open('test.shp') do |w| Geo::Reader.foreach('transl_1_1.shp', {:whitelist => ['exs']}) do |geom, attrs| #print "#{attrs.inspect}\n" w.write(geom, attrs) end end print "#{Time.now - start_time} sec.\n" exit # ここから下は別の話題 ix = Geo::import_epsg_crs(2451) # EPSG:2451 - 平面直角座標系 IX 系 wgs84 = Geo::import_epsg_crs(4326) # EPSG:4326 - WGS84 t = Geo::Transform.new(ix, wgs84) # IX 系から WGS84 への座標変換器 t_inv = Geo::Transform.new(wgs84, ix) # WGS84 から IX 系への座標変換器 pt = t.transform(0, 0) # IX 系の原点を WGS84 に座標変換 pt_inv = t_inv.transform(pt[0], pt[1]) # その点を IX 系に戻す。元に戻るか? print "IX origin is #{pt.inspect} in WGS84\n" print "#{pt_inv.inspect} must be (0, 0)\n" end