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这几天一直在研究关于路径规划的问题,postgis也是现学现用,由于SQL的语法掌握还不错,postgis仅需要熟悉常用的函数就行,关于常用的postgis函数,我已经结合网上的一些资料写了一篇文章,关于做一些GIS的空间分析,我们有两种选择,一是选择geotools,二结合postgis,两者选一个即可,我发现postgis+geoserver组合,本质上还是通过geotools来实现的,废话不多说,进入正题
一、路网shapfile文件导入数据库
1、创建数据空间数据库
具体做法在这里不再叙述,网上有许多的教程关于空间数据创建
2、导入shapfile文件
选择插件中的PostGIS shapfile and DBF Loader工具,点击出现如下对话框:
点击Add File按钮添加,所要导入的shapfile文件(注意:这里存放shapfile文件的路径必须为纯英文,路径中不能含有汉字,SRD必须设置,这里我设置为4326)
在Options点选下面对号
注意最后一个复选框必须打勾,以此来生成LineString类型,否则无法进行路径规划。
3、查看导入数据
选中roa_4m表格,点击上面的按钮可以查看表格数据。
二、路径规划函数生成
1、添加字段、
- --添加起点id
-
- ALTER TABLE roa_4m ADD COLUMN source integer;
-
- --添加终点id
-
- ALTER TABLE roa_4m ADD COLUMN target integer;
-
- --添加道路权重值
-
- ALTER TABLE roa_4m ADD COLUMN length double precision;
2、创建拓扑结构
- --为sampledata表创建拓扑布局,即为source和target字段赋值
-
- SELECT pgr_createTopology('roa_4m',0.0001, 'geom', 'gid');
3、创建索引
- --为source和target字段创建索引
-
- CREATE INDEX source_idx ON roa_4m("source");
-
- CREATE INDEX target_idx ON roa_4m("target");
-
-
- ALTER TABLE roa_4m ADD COLUMN x1 double precision; --创建起点经度x1
- ALTER TABLE roa_4m ADD COLUMN y1 double precision; --创建起点纬度y1
- ALTER TABLE roa_4m ADD COLUMN x2 double precision; --创建起点经度x2
- ALTER TABLE roa_4m ADD COLUMN y2 double precision; --创建起点经度y2
-
- UPDATE roa_4m SET x1 =ST_x(ST_PointN(geom, 1));
- UPDATE roa_4m SET y1 =ST_y(ST_PointN(geom, 1));
- UPDATE roa_4m SET x2 =ST_x(ST_PointN(geom, ST_NumPoints(geom)));
- UPDATE roa_4m SET y2 =ST_y(ST_PointN(geom, ST_NumPoints(geom))); --给x1、y1、x2、y2赋值
4、给索引赋值
- --为length赋值
- --设置为双向
- update roa_4m set length =st_length(geom);
- --将长度值赋给reverse_cost,作为路线选择标准
- ALTER TABLE roa_4m ADD COLUMN reverse_cost double precision;
- UPDATE roa_4m SET reverse_cost = st_length(geom);
5、路径函数的生成
- -- Function: pgr_fromctod(character varying, double precision, double precision, double precision, double precision)
-
- -- DROP FUNCTION pgr_fromctod(character varying, double precision, double precision, double precision, double precision);
-
- CREATE OR REPLACE FUNCTION pgr_fromctod(
- tbl character varying,
- startx double precision,
- starty double precision,
- endx double precision,
- endy double precision)
- RETURNS geometry AS
- $BODY$
-
- declare
-
- v_startLine geometry;--离起点最近的线
-
- v_endLine geometry;--离终点最近的线
-
-
-
- v_startTarget integer;--距离起点最近线的终点
-
- v_startSource integer;
-
- v_endSource integer;--距离终点最近线的起点
-
- v_endTarget integer;
-
-
-
- v_statpoint geometry;--在v_startLine上距离起点最近的点
-
- v_endpoint geometry;--在v_endLine上距离终点最近的点
-
-
-
- v_res geometry;--最短路径分析结果
-
- v_res_a geometry;
-
- v_res_b geometry;
-
- v_res_c geometry;
-
- v_res_d geometry;
-
-
-
- v_perStart float;--v_statpoint在v_res上的百分比
-
- v_perEnd float;--v_endpoint在v_res上的百分比
-
-
-
- v_shPath_se geometry;--开始到结束
-
- v_shPath_es geometry;--结束到开始
-
- v_shPath geometry;--最终结果
-
- tempnode float;
-
- begin
-
- --查询离起点最近的线
- --4326坐标系
- --找起点15米范围内的最近线
-
- execute 'select geom, source, target from ' ||tbl||
-
- ' where ST_DWithin(geom,ST_Geometryfromtext(''point('||startx ||' ' || starty||')'',4326),15)
- order by ST_Distance(geom,ST_GeometryFromText(''point('|| startx ||' '|| starty ||')'',4326)) limit 1'
-
- into v_startLine, v_startSource ,v_startTarget;
-
-
-
- --查询离终点最近的线
- --找终点15米范围内的最近线
-
- execute 'select geom, source, target from ' ||tbl||
-
- ' where ST_DWithin(geom,ST_Geometryfromtext(''point('|| endx || ' ' || endy ||')'',4326),15)
- order by ST_Distance(geom,ST_GeometryFromText(''point('|| endx ||' ' || endy ||')'',4326)) limit 1'
-
- into v_endLine, v_endSource,v_endTarget;
-
-
-
- --如果没找到最近的线,就返回null
-
- if (v_startLine is null) or (v_endLine is null) then
-
- return null;
-
- end if ;
-
-
-
- select ST_ClosestPoint(v_startLine, ST_Geometryfromtext('point('|| startx ||' ' || starty ||')',4326)) into v_statpoint;
-
- select ST_ClosestPoint(v_endLine, ST_GeometryFromText('point('|| endx ||' ' || endy ||')',4326)) into v_endpoint;
-
-
-
- -- ST_Distance
-
-
-
- --从开始的起点到结束的起点最短路径
-
- execute 'SELECT st_linemerge(st_union(b.geom)) ' ||
- 'FROM pgr_kdijkstraPath(
- ''SELECT gid as id, source, target, length as cost FROM ' || tbl ||''','
-
- ||v_startSource|| ', ' ||'array['||v_endSource||'] , false, false
- ) a, '
-
- ||tbl|| ' b
- WHERE a.id3=b.gid
- GROUP by id1
- ORDER by id1' into v_res ;
-
-
-
- --从开始的终点到结束的起点最短路径
-
- execute 'SELECT st_linemerge(st_union(b.geom)) ' ||
-
- 'FROM pgr_kdijkstraPath(
- ''SELECT gid as id, source, target, length as cost FROM ' || tbl ||''','
-
- ||v_startTarget|| ', ' ||'array['||v_endSource||'] , false, false
- ) a, '
-
- ||tbl|| ' b
- WHERE a.id3=b.gid
- GROUP by id1
- ORDER by id1' into v_res_b ;
-
-
-
- --从开始的起点到结束的终点最短路径
-
- execute 'SELECT st_linemerge(st_union(b.geom)) ' ||
-
- 'FROM pgr_kdijkstraPath(
- ''SELECT gid as id, source, target, length as cost FROM ' || tbl ||''','
-
- ||v_startSource || ', ' ||'array['||v_endTarget||'] , false, false
- ) a, '
-
- || tbl || ' b
- WHERE a.id3=b.gid
- GROUP by id1
- ORDER by id1' into v_res_c ;
-
-
-
- --从开始的终点到结束的终点最短路径
-
- execute 'SELECT st_linemerge(st_union(b.geom)) ' ||
-
- 'FROM pgr_kdijkstraPath(
- ''SELECT gid as id, source, target, length as cost FROM ' || tbl ||''','
-
- ||v_startTarget || ', ' ||'array['||v_endTarget||'] , false, false
- ) a, '
-
- || tbl || ' b
- WHERE a.id3=b.gid
- GROUP by id1
- ORDER by id1' into v_res_d ;
-
-
-
- if(ST_Length(v_res) > ST_Length(v_res_b)) then
-
- v_res = v_res_b;
-
- end if;
-
-
-
- if(ST_Length(v_res) > ST_Length(v_res_c)) then
-
- v_res = v_res_c;
-
- end if;
-
-
-
- if(ST_Length(v_res) > ST_Length(v_res_d)) then
-
- v_res = v_res_d;
-
- end if;
-
-
-
-
-
- --如果找不到最短路径,就返回null
-
- --if(v_res is null) then
-
- -- return null;
-
- --end if;
-
-
-
- --将v_res,v_startLine,v_endLine进行拼接
-
- select st_linemerge(ST_Union(array[v_res,v_startLine,v_endLine])) into v_res;
-
-
-
- select ST_Line_Locate_Point(v_res, v_statpoint) into v_perStart;
-
- select ST_Line_Locate_Point(v_res, v_endpoint) into v_perEnd;
-
-
-
- if(v_perStart > v_perEnd) then
-
- tempnode = v_perStart;
-
- v_perStart = v_perEnd;
-
- v_perEnd = tempnode;
-
- end if;
-
-
-
- --截取v_res
- --拼接线
-
- SELECT ST_Line_SubString(v_res,v_perStart, v_perEnd) into v_shPath;
-
-
-
- return v_shPath;
-
-
-
- end;
-
- $BODY$
- LANGUAGE plpgsql VOLATILE STRICT
- COST 100;
- ALTER FUNCTION pgr_fromctod(character varying, double precision, double precision, double precision, double precision)
- OWNER TO postgres;
(上面函数是不是不知道怎么定义,基本套路在这里postgresql存储过程)生成后的函数,可以在public中函数中查看。
三、PostGIS连接Geoserver发布数据,以及发布视图
1、geoserver连接postgis
点击数据存储---->添加新的数据存储
选择新建数据源 点击postgis
j将红线框选中部分,填写
数据名称--->要连接的数据库名称----->用户名------->密码------->保存
2、发布roa_4m表格为服务
点击图层----->添加新的资源----新建图层(下拉框中选择刚才上面所间的资源)
选择我们在postgis中数据表,点击发布即可
3、创建sql视图
方法和上述发布roa_4m表格类似,只不过在一步,选择 配置新的SQL视图。
编辑视图
1)填写视图名称(自己自定义)
2)SQL语句
select * from pgr_fromctod('roa_4m',%x1%, %y1%, %x2%, %y2%)
3)点击从SQL猜想的参数,D的默认值,全部为0,验证的正则表达式全部为^-?[\d.]+$
4)点击刷新,类型选为LineString类型,SRD为4326
5)点击保存,然后发布
四、OL调用demo
- <!DOCTYPE html>
- <html>
- <head>
- <meta charset="utf-8" />
- <title>室内路径规划</title>
- <link href="../script/ol4/ol.css" rel="stylesheet" />
- <style>
- #id {
- width:1000px;
- height:1000px;
- }
- </style>
- <script src="../script/ol4/ol.js"></script>
- </head>
- <body>
- <div id="map"></div>
- <script>
-
- var roadLayer = new ol.layer.Tile({
- source: new ol.source.TileWMS({
- url: 'http://localhost:8080/geoserver/cite/wms',
- params: { 'LAYERS': 'cite:roa_4', 'TILED': true },
- serverType: 'geoserver'
- })
- })
- var map = new ol.Map({
- target: document.getElementById("map"),
- layers: [
- roadLayer
- ],
- view: new ol.View({
- center: [117.34211730957, 49.6271781921387],
- projection: 'EPSG:4326',
- zoom: 4
- })
- });
- var startCoord = [117.34211730957, 49.6271781921387]
- var destCoord = [127.216133117676, 45.7485237121582]
- var params = {
- LAYERS: 'cite:testSqlView',
- FORMAT: 'image/png',
- };
- var viewparams = [
- 'x1:' + startCoord[0], 'y1:' + startCoord[1],
- 'x2:' + destCoord[0], 'y2:' + destCoord[1]
- //'x1:' + 12952117.2529, 'y1:' + 4836395.5717,
- //'x2:' + 12945377.2585, 'y2:' + 4827305.7549
- ];
- console.log(viewparams);
- params.viewparams = viewparams.join(';');
- result = new ol.layer.Image({
- source: new ol.source.ImageWMS(
- {
- url: 'http://localhost:8080/geoserver/cite/wms',
- params: params
- })
- });
- console.info(result);
- map.addLayer(result);
- </script>
- </body>
- </html>
五、效果图(蓝色线段)
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