What coordinate systems are supprted by Marklogic server?
MarkLogic can operate in 2 modes for geospatial coordinates: and WGS84 and Raw.
Related
I would like to calculate driving distance between two points writing SQL in Google BigQuery. I understand there is a method to calculate linear distance or "bird" miles using the following function: ROUND(ST_DISTANCE(ST_GEOGPOINT(C.LONGITUDE, C.LATITUDE), ST_GEOGPOINT(B.LNG_NBR, B.LAT_NBR))/1609.34,2) AS LINEAR_DIST_MILES
However, I am interested in driving distance instead of a linear distance. Is there a way to do this natively in Google BigQuery without needing to hit a Google Map API? I've also explored some solutions in R but that requires a Google Maps API key.
You would need two parts
good roads datasets
routing algorithms
BigQuery public datasets includes OpenStreetMaps, which is a reasonable dataset of roads (and other types of information) in most areas. There is also TIGER (bigquery-public-data.geo_us_roads) dataset which is US-specific.
Carto provides a sets of UDFs that can be used for routing. They've published an article how to connect things together:
https://carto.com/blog/how-to-do-route-optimization-at-scale-with-carto-bigquery/
I followed several example about geospatial support in Redis. I tried to add POINT features to my Redis dataset without any problem, and subsequently I can query POINT names within certain radius (in meters, km, miles) of a certain coordinate (or a certain member of POINT).
The next immediate feature i need to try is POINT-in-POLYGON query. Now I am curious :
Does Redis geo have the capability for storing polygon?
If yes, does this polygon capability come as native or need another stack of software/extension?
I think it is still not possible to store polygons with redis geospatial.
But I found an article explaining how to load a custom lua script to query points (stored in redis) within a polygon. The GEOSEARCH command allows you to do that for a bounding box out of the box if it is enough for you.
Is it possible to store binary data in GEODE or Gemfire?
In particular, I would like to store binary structures of sparse voxel octrees and retrieve them using a 3D coordinate.
If yes, is it possible to create a client in C++?
Without knowing much about voxel structures, I can't comment on the best way to do this. Geode/GemFire is designed to store binary data. With a C++ client, you should use Geode's PDX serialization. If it's a simple matter of retrieving a structure given a known coordinate, Geode should work well.
Hi I would like to obtain a list of public locations (restaurant, hotels, cinema etc.) neighbours based on GPS coordinates. Is this possible with BigQuery ?
If you have lat-lon or GPS coordinates as columns, you could definitely grab rectangular regions from BigQuery using WHERE comparisons on the coordinates and then aggregate on the selected rows.
The scalar operations available in BigQuery are pretty powerful too -- you can add a variety of arithmetic functions to your query and still get excellent performance.
You find listed example queries on the linked page:
Return a collection of points within a rectangular bounding box centered around San Francisco (37.46, -122.50).
Return a collection of up to 100 points within an approximated circle determined by the using the Spherical Law of Cosines, centered around Denver Colorado (39.73, -104.98).
GCP announced new geospatial data types and functions with BigQuery GIS.New functions and data types follow the SQL/MM Spatial standard and will be familiar to PostGIS users and anyone already doing geospatial analysis in SQL.
Also, a new lightweight visualization tool called BigQuery Geo Viz is announced which is designed for BigQuery users that want to plot and style their geospatial query results on a map.
Implementation, currently in alpha. You can request to get access.
More details can be found here - GCP Blog
I have come across a problem that I 've never solved before but I find it frequently implemented in various apps so I would like to ask if there is a common way to solve it. I have a set of analytics data each representing some logging action (i.e. info, warn etc). Each of this items has a location and a type (i.e. action). There can be millions of these items per area (depending on the area size or map zoom).
I am looking for the best way to store this set of data in my database. I am very comfortable with SQL Server but dont mind what db I have to use as long as it can handle the scalability requirements. If Amazon WS offers such a product or some other cloud solution then even better cause thats how we are planning to host this app. Google maps will be used to visualize the data.
Some requirements:
Be able to plot all data for a given map rectangle (a common google
map interface with markers representing the logging actions)
Be able to zoom in/zoom out and get relevant data for the new map rectangle
Be able to "group" markers in one bigger marker if data are very close. For instance, if point A is 1 km away from point B and I am seeing a map of 10 km radius then I should see two independent points, A and B. But if I zoom out to 500 km radius then point A and B are too close to each other so I would like to group them in one marker. Hopefully that's possible.
If SQL Server is not a good solution then a free, very cheap or cloud-based storage solution should be recommended (no I cant afford an Oracle).
All the queries above should be able to come back within milliseconds or somehow to be cached. Queries will be of the kind: Get me all analytics data for the given map window with zoom of the given rectangle latitude/longitude.
Thanks,
Yannis
If I undertsood correctly, there are 2 sides to your question:
1- A Database System, that supports storage and lookup of spatial data. Many of the free/open source RDBMS have spatial extensions: MySQL and Postgres (PostGIS) in particular. Spatial data are stored like any other data with the addition of spatial geometry attribute, which describes the shape of your data instance (point, rectangle, polygon, ellipse, ...). You can query spatial data entities, with spatial filters. And of course, spatial queries support joints and unions and almost all kind of SQL constructs.
2- A client/server api that would support rendering of spatial data (with the usual functions such as zoom in, zoom out, pan, etc.), caching and drill-down. As far as I know, there isn't one api that support all these features together, out the box. But there are some interesting apis that you might want to investigate.
Hope this helps.