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How do I efficiently search for all the landmarks within a range of a certain landmark
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I am trying to start with a geo search project that will find all landmarks in the 10 km/miles (not important for this story) of a particular landmark.
So for example, lets say I have a DB of a 1,000,000 landmarks. In order to find all landmarks in 10 miles range of a landmark with certain coordinates, I would have to calculate a distance between a landmark from my search and 1,000,000 landmarks.
Is there a better way to do that?
Alternative I was thinking is to categorize landmarks such as country, region, city, neighborhood, business, historical etc in such a way that business can be part of a neighborhood or city. City is a part of a region or a country etc. This can narrow a list of calculations, but is still looks like a lot of work do to in order for search to be fast and accurate.
Could google maps API help in anyway?
c# application-design geolocation google-maps
asked 2 hours ago
Dario Granich
19018
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up vote
1
down vote
favorite
I am trying to start with a geo search project that will find all landmarks in the 10 km/miles (not important for this story) of a particular landmark.
So for example, lets say I have a DB of a 1,000,000 landmarks. In order to find all landmarks in 10 miles range of a landmark with certain coordinates, I would have to calculate a distance between a landmark from my search and 1,000,000 landmarks.
Is there a better way to do that?
Alternative I was thinking is to categorize landmarks such as country, region, city, neighborhood, business, historical etc in such a way that business can be part of a neighborhood or city. City is a part of a region or a country etc. This can narrow a list of calculations, but is still looks like a lot of work do to in order for search to be fast and accurate.
Could google maps API help in anyway?
c# application-design geolocation google-maps
asked 2 hours ago
Dario Granich
19018
You could probably eliminate a good many simply by performing a quick Manhattan distance calculation and then performing a second filter afterwards to exclude landmarks which are within a 10km square but are outside the 10km radius.
– Neil
1 hour ago
add a comment |Â
up vote
1
down vote
favorite
up vote
1
down vote
favorite
I am trying to start with a geo search project that will find all landmarks in the 10 km/miles (not important for this story) of a particular landmark.
So for example, lets say I have a DB of a 1,000,000 landmarks. In order to find all landmarks in 10 miles range of a landmark with certain coordinates, I would have to calculate a distance between a landmark from my search and 1,000,000 landmarks.
Is there a better way to do that?
Alternative I was thinking is to categorize landmarks such as country, region, city, neighborhood, business, historical etc in such a way that business can be part of a neighborhood or city. City is a part of a region or a country etc. This can narrow a list of calculations, but is still looks like a lot of work do to in order for search to be fast and accurate.
Could google maps API help in anyway?
c# application-design geolocation google-maps
asked 2 hours ago
Dario Granich
19018
I am trying to start with a geo search project that will find all landmarks in the 10 km/miles (not important for this story) of a particular landmark.
So for example, lets say I have a DB of a 1,000,000 landmarks. In order to find all landmarks in 10 miles range of a landmark with certain coordinates, I would have to calculate a distance between a landmark from my search and 1,000,000 landmarks.
Is there a better way to do that?
Alternative I was thinking is to categorize landmarks such as country, region, city, neighborhood, business, historical etc in such a way that business can be part of a neighborhood or city. City is a part of a region or a country etc. This can narrow a list of calculations, but is still looks like a lot of work do to in order for search to be fast and accurate.
Could google maps API help in anyway?
c# application-design geolocation google-maps
c# application-design geolocation google-maps
asked 2 hours ago
Dario Granich
19018
asked 2 hours ago
Dario Granich
19018
asked 2 hours ago
Dario Granich
19018
asked 2 hours ago
Dario Granich
19018
asked 2 hours ago
Dario Granich
19018
19018
You could probably eliminate a good many simply by performing a quick Manhattan distance calculation and then performing a second filter afterwards to exclude landmarks which are within a 10km square but are outside the 10km radius.
– Neil
1 hour ago
add a comment |Â
You could probably eliminate a good many simply by performing a quick Manhattan distance calculation and then performing a second filter afterwards to exclude landmarks which are within a 10km square but are outside the 10km radius.
– Neil
1 hour ago
You could probably eliminate a good many simply by performing a quick Manhattan distance calculation and then performing a second filter afterwards to exclude landmarks which are within a 10km square but are outside the 10km radius.
– Neil
1 hour ago
You could probably eliminate a good many simply by performing a quick Manhattan distance calculation and then performing a second filter afterwards to exclude landmarks which are within a 10km square but are outside the 10km radius.
– Neil
1 hour ago
add a comment |Â
2 Answers
2
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up vote
4
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Since SQL Server 2008, there is a geography data type which stores locations (lat/lon pairs) and makes it easy for you to write location-related queries.
There is an existing StackOverflow answer that discusses this in-depth.
A basic query to find the nearest 7 items:
USE AdventureWorks2012
GO
DECLARE @g geography = 'POINT(-121.626 47.8315)';
SELECT TOP(7) SpatialLocation.ToString(), City FROM Person.Address
WHERE SpatialLocation.STDistance(@g) IS NOT NULL
ORDER BY SpatialLocation.STDistance(@g);
A basic query to find everything within 100m (second answer to the question)
-- Get the center point
DECLARE @g geography
SELECT @g = geo FROM yourTable WHERE PointId = something
-- Get the results, radius 100m
SELECT * FROM yourTable WHERE @g.STDistance(geo) <= 100
answered 2 hours ago
Flater
4,265716
add a comment |Â
up vote
2
down vote
Use a database with support for GIS (geographic information systems) queries. Most databases support this outright or have extensions, but the details will be database-specific (in their answer, Flater shows the syntax for SQL server).
If you need to implement such queries within your application, you can implement a data structure that allows spatial queries, e.g. a k-d Tree. This is like a binary search tree, except that each level of the tree partitions on a different coordinate dimension. This allows you to restrict the search to a smaller set of feasible candidates. Effectively, you translate your search “10km radius†into bounds for each coordinate dimension, and tighten the bounds as you recurse into the tree.
answered 1 hour ago
amon
80.5k20152238
add a comment |Â
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
4
down vote
Since SQL Server 2008, there is a geography data type which stores locations (lat/lon pairs) and makes it easy for you to write location-related queries.
There is an existing StackOverflow answer that discusses this in-depth.
A basic query to find the nearest 7 items:
USE AdventureWorks2012
GO
DECLARE @g geography = 'POINT(-121.626 47.8315)';
SELECT TOP(7) SpatialLocation.ToString(), City FROM Person.Address
WHERE SpatialLocation.STDistance(@g) IS NOT NULL
ORDER BY SpatialLocation.STDistance(@g);
A basic query to find everything within 100m (second answer to the question)
-- Get the center point
DECLARE @g geography
SELECT @g = geo FROM yourTable WHERE PointId = something
-- Get the results, radius 100m
SELECT * FROM yourTable WHERE @g.STDistance(geo) <= 100
answered 2 hours ago
Flater
4,265716
add a comment |Â
up vote
4
down vote
Since SQL Server 2008, there is a geography data type which stores locations (lat/lon pairs) and makes it easy for you to write location-related queries.
There is an existing StackOverflow answer that discusses this in-depth.
A basic query to find the nearest 7 items:
USE AdventureWorks2012
GO
DECLARE @g geography = 'POINT(-121.626 47.8315)';
SELECT TOP(7) SpatialLocation.ToString(), City FROM Person.Address
WHERE SpatialLocation.STDistance(@g) IS NOT NULL
ORDER BY SpatialLocation.STDistance(@g);
A basic query to find everything within 100m (second answer to the question)
-- Get the center point
DECLARE @g geography
SELECT @g = geo FROM yourTable WHERE PointId = something
-- Get the results, radius 100m
SELECT * FROM yourTable WHERE @g.STDistance(geo) <= 100
answered 2 hours ago
Flater
4,265716
add a comment |Â
up vote
4
down vote
up vote
4
down vote
Since SQL Server 2008, there is a geography data type which stores locations (lat/lon pairs) and makes it easy for you to write location-related queries.
There is an existing StackOverflow answer that discusses this in-depth.
A basic query to find the nearest 7 items:
USE AdventureWorks2012
GO
DECLARE @g geography = 'POINT(-121.626 47.8315)';
SELECT TOP(7) SpatialLocation.ToString(), City FROM Person.Address
WHERE SpatialLocation.STDistance(@g) IS NOT NULL
ORDER BY SpatialLocation.STDistance(@g);
A basic query to find everything within 100m (second answer to the question)
-- Get the center point
DECLARE @g geography
SELECT @g = geo FROM yourTable WHERE PointId = something
-- Get the results, radius 100m
SELECT * FROM yourTable WHERE @g.STDistance(geo) <= 100
answered 2 hours ago
Flater
4,265716
Since SQL Server 2008, there is a geography data type which stores locations (lat/lon pairs) and makes it easy for you to write location-related queries.
There is an existing StackOverflow answer that discusses this in-depth.
A basic query to find the nearest 7 items:
USE AdventureWorks2012
GO
DECLARE @g geography = 'POINT(-121.626 47.8315)';
SELECT TOP(7) SpatialLocation.ToString(), City FROM Person.Address
WHERE SpatialLocation.STDistance(@g) IS NOT NULL
ORDER BY SpatialLocation.STDistance(@g);
A basic query to find everything within 100m (second answer to the question)
-- Get the center point
DECLARE @g geography
SELECT @g = geo FROM yourTable WHERE PointId = something
-- Get the results, radius 100m
SELECT * FROM yourTable WHERE @g.STDistance(geo) <= 100
answered 2 hours ago
Flater
4,265716
answered 2 hours ago
Flater
4,265716
answered 2 hours ago
Flater
4,265716
answered 2 hours ago
Flater
4,265716
4,265716
add a comment |Â
add a comment |Â
up vote
2
down vote
Use a database with support for GIS (geographic information systems) queries. Most databases support this outright or have extensions, but the details will be database-specific (in their answer, Flater shows the syntax for SQL server).
If you need to implement such queries within your application, you can implement a data structure that allows spatial queries, e.g. a k-d Tree. This is like a binary search tree, except that each level of the tree partitions on a different coordinate dimension. This allows you to restrict the search to a smaller set of feasible candidates. Effectively, you translate your search “10km radius†into bounds for each coordinate dimension, and tighten the bounds as you recurse into the tree.
answered 1 hour ago
amon
80.5k20152238
add a comment |Â
up vote
2
down vote
Use a database with support for GIS (geographic information systems) queries. Most databases support this outright or have extensions, but the details will be database-specific (in their answer, Flater shows the syntax for SQL server).
If you need to implement such queries within your application, you can implement a data structure that allows spatial queries, e.g. a k-d Tree. This is like a binary search tree, except that each level of the tree partitions on a different coordinate dimension. This allows you to restrict the search to a smaller set of feasible candidates. Effectively, you translate your search “10km radius†into bounds for each coordinate dimension, and tighten the bounds as you recurse into the tree.
answered 1 hour ago
amon
80.5k20152238
add a comment |Â
up vote
2
down vote
up vote
2
down vote
Use a database with support for GIS (geographic information systems) queries. Most databases support this outright or have extensions, but the details will be database-specific (in their answer, Flater shows the syntax for SQL server).
If you need to implement such queries within your application, you can implement a data structure that allows spatial queries, e.g. a k-d Tree. This is like a binary search tree, except that each level of the tree partitions on a different coordinate dimension. This allows you to restrict the search to a smaller set of feasible candidates. Effectively, you translate your search “10km radius†into bounds for each coordinate dimension, and tighten the bounds as you recurse into the tree.
answered 1 hour ago
amon
80.5k20152238
Use a database with support for GIS (geographic information systems) queries. Most databases support this outright or have extensions, but the details will be database-specific (in their answer, Flater shows the syntax for SQL server).
If you need to implement such queries within your application, you can implement a data structure that allows spatial queries, e.g. a k-d Tree. This is like a binary search tree, except that each level of the tree partitions on a different coordinate dimension. This allows you to restrict the search to a smaller set of feasible candidates. Effectively, you translate your search “10km radius†into bounds for each coordinate dimension, and tighten the bounds as you recurse into the tree.
answered 1 hour ago
amon
80.5k20152238
answered 1 hour ago
amon
80.5k20152238
answered 1 hour ago
amon
80.5k20152238
answered 1 hour ago
amon
80.5k20152238
80.5k20152238
add a comment |Â
add a comment |Â
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You could probably eliminate a good many simply by performing a quick Manhattan distance calculation and then performing a second filter afterwards to exclude landmarks which are within a 10km square but are outside the 10km radius.
– Neil
1 hour ago