Spatial

问题 I'm looking for information on how to use MySQL geometry types in .NET. I'm using Sub-sonic for ORM and don't really need to support much more than MySQL's POINT type. The MySQL .NET connector seems to return point data as a byte[] array in the OpenGIS WKB format. What libraries are recommended for working with this WKB format? Alternatively, since I only need support for Point, examples on converting WKB to/from a .NET type would probably suffice. Assuming I can find (or build) a class that

问题 is there any posibility to show only Germany Country Borders and inner Data with Mapbox ? I dont want the rest of the world displayed. Thankx, Markus 回答1: Yes. Use the Germany GeoJSON from http://code.highcharts.com/mapdata/. Upload it as a dataset, export it to tilesets, and then to a map as a layer. Delete all other layers. 来源： https://stackoverflow.com/questions/40886151/filter-out-country-with-mapbox

问题 Since a couple of versions, h2 does have support for spatial geometries. It's not a problem to select and insert geometries in java. But how can insert them in pure sql? Documentation shows it uses WKT. But when I try to insert in WKT I got an error. That's an example insert: insert into feature (id, name, description, geom) values (1, 'example name', 'example description', 'SRID=4326;POINT(7 52)'); Thanks for any hints! 回答1: As far as I see, the suffix SRID=4326 is not WKT (Well-Known Text),

问题 I receive spatial queries to my API in lat/lon coordinate pairs. My spatial data is in projections that don't cover the entire globe, which follows that some queries are out of bounds. I'd like to respond to wrong queries with helpful error message. Rather than try to find out some in GIS specifications or standards what boundaries each projection has (and getting correct lat/lon pairs from those), I'd like to know wether I could either ask the limits from Postgis or ask if specific point is

问题 I have an interesting/annoying issue with finding lat and long of land marks inside the rectangular boundary. I believe my two points are inside my rectangular boundary. but as you can test yourself the result of the the first select is false instead of true! DECLARE @boundingRect varchar(1000) DECLARE @maxLat VARCHAR(20) DECLARE @minLong VARCHAR(20) DECLARE @minLat VARCHAR(20) DECLARE @maxLong VARCHAR(20) set @maxLat ='-36.06631759541187' set @minLong ='125.23310677812492' set @minLat ='-44

问题 I want to create a world street map using Rstudio. I have this code: countries_map <-map_data("world") world_map<-ggplot() + geom_map(data = countries_map, map = countries_map,aes(x = long, y = lat, map_id = region, group = group), fill = "light blue", color = "black", size = 0.1) the problem: I want to see the names of the countries and to see the map like this one: Thanks for your help! 回答1: We can use the leaflet package. See this link to learn the choice of base map (https://leaflet

问题 I have a series of steps I need to complete on a list of SpatialLinesDataFrame ('lines' herein) objects based on their relationships with individual features within a multi-feature SpatialPolygonsDataFrame ('polygons') object. In short, each line list element originates inside a single polygon feature, and may or may not pass through one or more other polygon features. I want to update each line element to connect origin polygons to the first point of contact for each individual polygon

问题 Below dataframe contains the information about the lat, long , state and city. I want to find the three nearest cities for every city given in the dataframe. For example, from the below dataframe, Oklahoma city and Colarado SPringd nearest to Albuquerque, So three nearest city to Albuquerque should be saved in other dataframe named nearest_AL(I don't know how to get this result, that'y I tried to gave an idea by creating a data frame). dataframe<-data.frame(long=c("-106.61291","-81.97224","

问题 I have a shapefile which is the national boundary line of Chile. If possible, I would like to randomly generate e.g. 1000 polygons within this area. I'm wondering what the best way would be to go about this in R? I thought maybe, loading the shapefile using the 'shapefiles' package, then creating a point dataset using something available in 'spatstat'. Then I could create circular polygons based around these points... This is mostly hypothetical and I don't know if its possible. I have some

问题 I'm using the map layer wizard for the first time in SSRS so we can add spatial data to the map. We get this error from the wizard: Unable to determine the spatial data type in the specified dataset field... The data type for the spatial data is geography. The spatial data looks like this when executed in the Query Designer: POINT (2.41866741166689 48.9082239283949) POINT (1.92902094274567 47.9294603618455) POINT (2.25244361602031 48.9619440062058) POINT (1.91174331024445 47.9109595746068)