A query for geometric features based on their spatial relationship.

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1answer
21 views

How to show a map with queries from a map file connected to postgres in browser using javascript?

So, the problem is how to show a map in browser using javascript? I have a map file with 2 layers in it: "peta" is a shp data from postgis and "korban" is a numeric data from postgresql. And then I ...
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38 views

Query tool option missing in publishing maps with geoexplorer

I want visitors to a website with a published map created by Opengeo Geoexplorer to query the layer (layers, if possible) it contained. I am able to use the query tool while composing my map within ...
1
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0answers
70 views

I have WIKI VGI Java based query doubts?

I have a code snippet in Java to query wiki volunteered GIS. This is first time I am using java and finding it difficult to answer some queries. package org.wikibrain.cookbook.MOOC; import ...
11
votes
1answer
133 views

Identify points in a shapefile that have no other point within x km with QGIS

This is probably a naive question but I am struggling as a new user to QGIS. I have a very large shapefile (275,000 points, but can break this into about 10 subregions if necessary for faster ...
2
votes
1answer
67 views

Get feature data from lat long input QGIS

In QGIS, I have a polygon dataset with feature data. I would like to extract data from this dataset using a latitude and longitude. To be more clear, I have a list of 1000 coordinates. I would like ...
2
votes
2answers
224 views

drawing concentric circles in arcmap 10.1

I am using ArcMap 10.1 and I would like to know if there is a way to draw circles at a specific distance from a georeferenced coordinate. I have a property and I would like to know how far you can ...
5
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2answers
69 views

How to select random adjacent census tract

I have set of census tracts spaced out across a city and I would like to randomly choose an adjacent census tract to explore nearby demographic data. I'm not sure if there is an easy process for ...
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1answer
84 views

How to count number of points/lines/polygons contained within a polygon, when the feature to count is from a server

I'm currently running a study where I need to query the number of points/lines/polygons that are contained within a project boundary - intersecting lines and polygons need to be counted as well. The ...
2
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1answer
38 views

How do you create a query that will result with the adjacent parcels?

I have a shapefile with parcel data, and I am trying to create a query that will render a list or something similar that will list adjacent parcels to a specific parcel. I want to be able to select ...
2
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1answer
86 views

How to get the width and height of a rectangular polygon in PostGIS

I have a table with point features saved in the my PostgreSQL database, and I can run the following query to get the extent of the point features and I turned the extent back into a geometry: SELECT ...
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2answers
76 views

how to do simple self join and touches function in postgis?

I am having trouble with this query and neighbor calculation in PostGis. I want to find out which are the neighbors of Sweden in the table COUNTRIES which has column 'the_geom' for geometry and ...
0
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1answer
106 views

How can I find the segment of a line that lies within a polygon using Postgis?

Given a "road", represented by a line, that crosses a "state", represented by a polygon: What is the SQL query I can use to find the segment of the road that is within the state? A concrete example. ...
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1answer
82 views

ST_Within from centroid of geometry

I am looking at doing a spatial query where I can find when the center of one feature falls within another. For example, when the center (centroid) of a building falls within a grid tile. I know I can ...
3
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1answer
526 views

Problem PostGIS Spatial Query ST_Contains ST_Disjoint ST_Intersects

I'm working on a project with two different tables inside a database. One contains points in a column geometry(Point,4326) type and the second one has a column geometry(MultiPolygon,4326). Now I would ...
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0answers
16 views

Count gaps between polygon in spatialite

I have a database (.db) with a table that contains thousands of polygons containing id and geometry. I like a query that can get me the 'number of errors where there are gaps between polygons". How ...
1
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2answers
94 views

Is it possible to run a spatial query in QGIS 2.0 across multiple layers using a user-specified radius from a point?

I would like to be able to click on a point on a map to select all vector features (from multiple layers) within a specified radius of the point. Can anyone point me in the direction of how to do this ...
1
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1answer
70 views

Problem with runing a loop in a query in PostGIS

I am new to PostGIS and I have a question which can't solve. I have a table of buildings each having a value for number of people living in it. I would like to calculate the total value (sum of number ...
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0answers
55 views

PoI Range query

I have a dataset of 100,000 PoIs represented by (id, name, longitude, latitude).. I would like to perform a large number (around 10,000) search operations on this dataset. each search operation ...
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0answers
106 views

Find area with highest relative density of one type of object

I'm using PostgreSQL/PostGIS and I have an advanced type of query. My database contains two types of object - let's say pubs and churches :) Is there a way that I can find the area with the densest ...
7
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1answer
549 views

What is difference between ST_DWithin and ST_Distance for proximity search in PostGIS?

I have records stored in a table with latitude/longitude coordinates stored in a geometry field. I want to find all records nearby a user supplied reference point. Note "nearby" probably means less ...
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0answers
168 views

How to add a MSSQL spatial layer using Python?

I'm having difficulty adding a MSSQL spatial data layer using Python. The database is password protected, and I can add the layer without any problems using the built in feature, but I can't make it ...
2
votes
2answers
773 views

Postgis, get the points that are x meters near another point, in meters

I'm trying to find the points within a certain distance, in meters, from another point. I'm using the function ST_Buffer, but I don't get how to express the distance in meters. I'm trying with ...
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3answers
342 views

QGIS spatial join, calculating distance from polygon to point layer

I am trying to perform a kind of 'spatial join' in Arcgis, joining to a polygon layer atributes of the closest feature of a point layer, as well as distance. But 'spatial query' doesn't offer an ...
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2answers
127 views

geoprocessing across multiple vector layers QGIS2

I have 6 layers of point data (each layer is one year), where data in each layer are distributed throughout a grid, and the grid is identical in each layer. I'd like to extract data from each layer, ...
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2answers
193 views

Best way to figure out which regions a point is in a shape file?

I'm trying to figure out the best way on Android to figure out if a point in region as defined in a shapefile. For instance, I might want to know what country I'm in using the Geo Common's Shapefile ...