I am experimenting drawing curved line from Origin to Destination in Cartodb. I was able to do so once, however, failed the second and third time.
Could anyone offer me some insights into the following code and help me debug?
I am using CartoDB and start with a table of centroid points for all the countries.
Step 1:CHANGE THE REFERENCE SYSTEM I used the following code
INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 953027, 'esri', 53027, '+proj=eqdc +lat_0=0 +lon_0=0 +lat_1=60 +lat_2=60 +x_0=0 +y_0=0 +a=6371000 +b=6371000 +units=m +no_defs ', 'PROJCS["Sphere_Equidistant_Conic",GEOGCS["GCS_Sphere",DATUM["Not_specified_based_on_Authalic_Sphere",SPHEROID["Sphere",6371000,0]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Equidistant_Conic"],PARAMETER["False_Easting",0],PARAMETER["False_Northing",0],PARAMETER["Central_Meridian",0],PARAMETER["Standard_Parallel_1",60],PARAMETER["Standard_Parallel_2",60],PARAMETER["Latitude_Of_Origin",0],UNIT["Meter",1],AUTHORITY["EPSG","53027"]]'); Step 2:CREATE THE LINES
update world_borders_coarse_2013 set the_geom= (select st_transform( st_segmentize( st_makeline( st_transform(world_borders_coarse_2013.the_geom,953027), st_transform(b.the_geom,953027)),100),4326) from world_borders_coarse_2013 b where b.name='China' ) It should give me the curved lines between China to all the other places. However the reality is that I have the "the_geom" column as "line", but nothing shows in the "map view".
Would anyone give me some suggestion to change the code?
أكثر...
Could anyone offer me some insights into the following code and help me debug?
I am using CartoDB and start with a table of centroid points for all the countries.
Step 1:CHANGE THE REFERENCE SYSTEM I used the following code
INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 953027, 'esri', 53027, '+proj=eqdc +lat_0=0 +lon_0=0 +lat_1=60 +lat_2=60 +x_0=0 +y_0=0 +a=6371000 +b=6371000 +units=m +no_defs ', 'PROJCS["Sphere_Equidistant_Conic",GEOGCS["GCS_Sphere",DATUM["Not_specified_based_on_Authalic_Sphere",SPHEROID["Sphere",6371000,0]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Equidistant_Conic"],PARAMETER["False_Easting",0],PARAMETER["False_Northing",0],PARAMETER["Central_Meridian",0],PARAMETER["Standard_Parallel_1",60],PARAMETER["Standard_Parallel_2",60],PARAMETER["Latitude_Of_Origin",0],UNIT["Meter",1],AUTHORITY["EPSG","53027"]]'); Step 2:CREATE THE LINES
update world_borders_coarse_2013 set the_geom= (select st_transform( st_segmentize( st_makeline( st_transform(world_borders_coarse_2013.the_geom,953027), st_transform(b.the_geom,953027)),100),4326) from world_borders_coarse_2013 b where b.name='China' ) It should give me the curved lines between China to all the other places. However the reality is that I have the "the_geom" column as "line", but nothing shows in the "map view".
Would anyone give me some suggestion to change the code?
أكثر...