A geometric element defined by a pair of x,y coordinates.

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6
votes
4answers
444 views

How to calculate the “depth” of a linestring using postgis

I have linestring features, which look like bent linestrings, hemicycles or convex or concave linestrings. In the moment I can select the distance between the startpoint and endpoint of each feature. ...
-2
votes
1answer
212 views

QGIS and Python - create line with multiple points in postgis [closed]

How can I create a line, with Python functions, with many points that are records in Postgis? Thank you
1
vote
2answers
87 views

Alternative to ST_ClosestPoint, one which returns a vertex of the geometry

ST_ClosestPoint returns the closest point on a geometry, as in the example at http://postgis.net/docs/ST_ClosestPoint.html What I need is to get the closest point which is already a part of the ...
5
votes
4answers
542 views

How do I fill in serial letters (AA, AB,AC…,BA,BB,BC…ZZ) to a shape?

(I am using ArcGIS software, ArcMap...) MY PROBLEM I have a shape file containing points. The shape file contains 3 columns named FID, Shape* and Label. In the column I want to fill in AA, AB, ...
0
votes
1answer
92 views

How to display coordinates of a point in a projected cooridante system?

I want to check the coordinates of a point. On selecting this point in ArcGIS it displays a latitude and Longitude . In ArcGIS I found an option in 'Identity Tool' that the Latitude and Longitude ...
2
votes
2answers
104 views

Creating a circle with points

I want to arrange 96 points as a circle/ring. Is there a way to make this automatically, for example "Buffer", "vertices"...? Kind regards, Stefan
1
vote
0answers
49 views

How to auto-fill a new point vector in a vector layer?

When I work in-situ I manually add points in my shape-file. I would like that when I add a new point some attributes would already filled with values calculated programmatically. E.g in my first ...
4
votes
5answers
4k views

How do I create a line between two points with a common field?

Does anyone know how I could create a line between two points that have a common code? For example: I have the start and end point of a pipe as a lat/long for a network of pipes, each with a ...
0
votes
1answer
41 views

QGIS proximity raster with extent beyond original coverage?

I need a raster coverage of distances from points outside the geographic region of interest, and am having trouble doing this with QGIS. Questions like this one (Calculating distance to points in ...
1
vote
1answer
224 views

Postgresql view with Point geometry returns QGIS error “(the_geom) sql = is an invalid layer and cannot be loaded”

I want to create a Postgresql view using point data. When I create the view, the geometry_columns table updates appropriately. Attempting to load in QGIS produces the error “(the_geom) sql = is an ...
3
votes
1answer
289 views

How to create linestrings with a definite angle and length, that are fixed to a point

I want to create linestrings with a definite angle (e.g. 160°) and length (e.g. 2m) that are fixed to a number of points of another linestring. So, I want to use the ST_DumpPoints function to find the ...
1
vote
0answers
28 views

QGIS rule-based point style responding to number of co-located objects?

I am mapping the geolocated location information for 5.5k Twitter profiles as point data. Many of them have the same location ie "London, UK" meaning that they return identical coordinates. On the map ...
0
votes
1answer
62 views

Point to point distance over specified distance

I need to calculate the distance between neighbouring points which conform to a staggered line. I have two point datasets, one being the baseline and another the monitor. The points typically reside ...
0
votes
0answers
38 views

grass plugin in QGIS all of sudden not working as expected

The previous week I was able to use the grass scripts in the QGIS 2.0.1 Dufour toolbox, but today they do not seem to be working. I am not sure where to place a '-c' which was a solution to the same ...
1
vote
3answers
513 views

Generate random location within specified distance of a given point

In a simulation (not using any GIS), I need to generate a random location that is within a specified distance of a given location. I found a very helpful post here on this exact topic: How to ...
2
votes
1answer
130 views

Moving a shapefile point to specific coordinates

In QGIS is there a simple way to move a shapefile point in a shapefile point file to specific coordinates? Without exporting the points to WKT changing the x,y values and then importing the WKT via ...
8
votes
1answer
128 views

Is “puntal” an accepted and defined geometric term?

There are definitions for the geometric qualities of polygons and lines: polygonal: Having many angles; hence characteristic of a polygon. Ref: http://en.wiktionary.org/wiki/polygonal ...
0
votes
0answers
22 views

How to divide my area into adjecent polygons containing 80 points each? [duplicate]

I have a couple of thousand points in my dataset. I need to create clusters that each consists of 80 points. The specific selection of which points to put into a cluster is not critical - only the ...
1
vote
2answers
396 views

Creating a 3D line feature based on 3D point features

In ArcGIS for Desktop 10.0, is it possible to create a 3D line feature by drawing a line that connects 3D point features?
9
votes
5answers
11k views

How to find the distance of a point along a polyline?

We need to find the distance of a series of point along a given polyline. We have a polyline dataset repsenting rivers in a catchment, broken up into river reaches (FID 1 through 35 for example). We ...
3
votes
1answer
56 views

Exploratory search for clusters in point data

This is a more conceptual than practical question and is about exploratory cluster identification. While there are very specific meanings in the geography canon as to what they are, in economics they ...
2
votes
3answers
688 views

Calculate min distance between points in PostGIS

I have point layer in PostGIS database. Help please with query which add for each points in layer distance in attribute table between this point and another nearest point. Thanks! Update Calculate ...
3
votes
1answer
60 views

How many polygons under a point (ArcGIS solution preferred)

Opposite of Point in Poly. How many polygons underneath a point. I have a point layer with many points. I have a polygon layer with many polygons. I need to add an attribute to the points that ...
1
vote
2answers
126 views

Extract a LineString from LineString by two Points

I am using PostGIS2.0 and PostgreSQL9.3. I have LineString in Spatial-Ref 4326 like geom:= ST_GEOMETRYFROMTEXT('LINESTRING(60.7014631515719 56.8441322356241,60.7023117507097 ...
6
votes
2answers
450 views

How to remove small “salt & pepper” polygons from a layer?

I have a map made up of multiple polygons, with a few hundred thousand points very small polygons on within it. I need the larger polygons, but not the points small polygons. How do I select and ...
1
vote
1answer
119 views

Sum of point attributes inside hexagons using QgiS UI

I'm very new to Qgis so I would very much appreciate any help you can give me. I have a point shapefile that corresponds to locations of animals captured. I've joined a table to this shapefile with ...
4
votes
1answer
215 views

Calculate distance to median point for a group of points in ArcGIS 10.1

I have a shapefile called "household_points" of ~2,000 points, which are divided into about 100 sites. The shapefile has a field in the attribute table called "SNAME" and in the field each point is ...
2
votes
0answers
40 views

Update PG table setting an area_id

I have a table with lots of points which I'd like to update and set a consecutive area_id to every point "group". I define a point "group" as points that are within a 500 meters radius. The raw table ...
1
vote
0answers
79 views

How to find locations on a conditional search [closed]

Hope you can help I have a set of points evenly distributed to 500m intervals, and stored elevation. I want to find from a given location any other point with the lowest elevation within a 1,000m ...
2
votes
1answer
124 views

How to efficiently render and enable user interaction on thousands of points with Leaflet?

I've got a large dataset comprised of about 10k points representing gas stations. Some of these gas stations sell diesel fuel, others do not. In my web map, I want to let the user switch between ...
0
votes
1answer
136 views

How to transfer attribute of nearest Point to Line feature?

Feature class 1: Addresses (Point) Feature class 2: Road centerlines (Polyline) Which is the most appropriate tool for transferring the Address attribute (e.g. Road No. or Bldg) to the nearest Road ...
4
votes
2answers
108 views

How to identify gaps in linear point data in FME?

I have been given a spreadsheet which contains coordinates of welds along a pipeline. I'm using FME to create points from the coordinates. On average, the points are roughly 11 metres from each ...
1
vote
2answers
74 views

QGIS point sampling tool really slow for polygons?

I have a large field of randomly distributed points (100,000 of them to be precise), and I'd like to get values for a variety of raster and polygon coverages for each point. I've been using the QGIS ...
1
vote
1answer
264 views

Measuring Distance from Point to Point Along a Path in ArcMap

I am looking at a village and want to find the distance from each house (point) to the pagoda (point). However, I want the distance to be measured along a path (which I digitized as a polyline) and ...
0
votes
0answers
35 views

What is the easiest way to get points Info from OSM

I need to parse some OSM XML data to get some nodes with their tags. Does a program or script already exist to do this? The result can be any format that I can parse to DB, e.g. XML, CSV, txt file ...
1
vote
1answer
77 views

Point symbology in SLD file

I would like to create a style file for a layer in Geoserver. I have point geometries and the SLD cookbook does give nice examples for the simple ways to create your symbology. However, I would like ...
0
votes
1answer
89 views

Code-Point Polygon Data and Google Maps

I'm currently working with OS Code-point polygons and google maps coordinates. I have google maps point coordinates for a list of houses which are located at the center of each full postcode ...
4
votes
6answers
2k views

How to represent several points with same coordinates on map?

I'm working on Arcgis 10. I have a point shapefile representing events with several points having coinciding coordinates (They have the same coordinates). For representing them in a dynamic way, I ...
2
votes
0answers
226 views

Updating SDE point feature classes with SQL SERVER 2008 R2 [closed]

I am contacting you in hope that you can help me resolve an issue using SQL Server 2008 R2 to push updates to a SDE point feature class. We are using a C# app that uses ArcGIS Runtime to edit the ...
5
votes
2answers
220 views

How to detect duplicates and keep only one?

I've got a table with lots of points (200.000). Some of them are duplicates (not exactly but e.g. a metro station has eight entrances) and I want to keep only one of these metro entrances. I am able ...
1
vote
1answer
51 views

How to symbolize a large amount of points with lots of color

I have an interactive map with a very large amount of different points. Depending on user selection, various points are shown or not-shown. These points are divided into several categories, each ...
0
votes
0answers
93 views

Create shape file with point

I am trying to create a .shp file with Point shapes. I am following this tutorial: http://docs.geotools.org/latest/userguide/tutorial/feature/csv2shp.html I create the project, no syntax error and ...
2
votes
2answers
816 views

script to create points in interval 0.125 decimal degree

I have a polygon shapefile. I want to create points at an interval of 0.125 decimal degrees in this polygon. How can I create a script with python in ArcGIS 10 to automate the process of create ...
2
votes
1answer
478 views

Arcgis Javascript latitude and longitude convert to WGS_1984_UTM_Zone_36N

I am using Arcgis Javascript api. I have two points comes from Google maps like this x:-111.67095840000002 y: 32.7558935 I wanna use this points on my Arcgis map. My map spatial reference is using ...
0
votes
0answers
26 views

Bounding Boxes around nearby points [duplicate]

I've got a table with 200.000 points. My aim is to draw bounding boxes around points where this point have the same name and that are in a maximum distance of 500 meters to each other. I guess I can ...
0
votes
1answer
62 views

How to create more than one mean coordinate in QGIS?

I have a point shapefile with several thousands of points in it. I've split the points up into spatial groups using a vectorgrid and pointcount. I wish to create a mean coordinate for each group of ...
2
votes
1answer
205 views

How to calculate mean coordinates from big point datasets?

I know there are several questions related to speed issues in QGIS, but I am having problems when running Ftools. I have a vector with ~70,000 points in it. When I run the generate mean coordinates ...
9
votes
1answer
199 views

Proximity in space and time

I have some point data which represent daily lat-lon locations of an animal, with an associated timestamp. I would like to identify all points where STATIONARY = TRUE. A point qualifies as being ...
0
votes
0answers
27 views

How to split a feature using GDAL

I want a feature to be cut into 2 or more based on deviation of a segment i.e., the angle between 2 successive segments. At places, I may also require to merge 2 or more features.
15
votes
4answers
1k views

algorithm to place maximum number of points within constrained area at a minimum spacing

I have a polygon layer that describes a constraint; I wish to add points within this area. I want to add as many points as possible, but they must have a minimum spacing between them. Is it possible ...