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

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1answer
77 views

What is the best way to display point data (with standard deviation) using QGIS/SAGA/Manifold?

I would like to display point data values (indicating biomass at a point) but also to show the standard deviation value for each point. What would be the best method to do this in QGIS (I'm a basic ...
0
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0answers
145 views

Create a buffer area for a point c#

I am wondering to create a point/line based buffer zones in order to enhance my understanding for buffer concept in the GIS. The buffer zones can be any circle or region around a point, particularly, ...
1
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0answers
87 views

How to change icon symbols in QGIS? Can icons have JavaScript animations?

There are a lot of SVG files located in the "QGIS Dufour" Program Files folder on my PC. I was thinking that I could find the symbol that I want to change in the GUI in this listing in InkScape so I ...
0
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0answers
89 views

Building real-time point/polyline connection in GIS

In the first instance I need to create the network by constructing the basic elements, the nodes and links. This is relatively easy work as SharpMap has provided geometry tools that allow users to ...
1
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1answer
74 views

QGIS how to compute a trendline of two point lines?

Does anyone know how to compute a trendline for two lines of points? I have two lines of points of a 10 km long urban road. 1st line is one driving direction and the 2nd line of points ist the other ...
2
votes
1answer
32 views

Get coodinates from point shapefile

I converted a line shapefile to points as you can see in the attached image. Is there a way to know the coordinates of each point? Any help would be really appreciated! PD Im using QGIS 1.8.0
4
votes
3answers
533 views

How to join number of point features into attribute of nearest line segment

I have point shapefile with lot of attributes, that represent road accidents and line shapefile with highways. What i want is to join attribute into line shapefile with value, that represent number of ...
4
votes
4answers
726 views

How to randomly subset X% of selected points?

What methods are available in ArcGIS 10.2 to randomly subset a selection of points. For example, in the attached screenshot I am interested in keeping 20% of the selected points and deleting the ...
7
votes
2answers
3k views

PostGIS: Find points that lie within a set of coordinates

I have a PostGIS db, and I want to find the points that lie within some region (a bounding box). I have two sets of coordinates, from which I can get all four rectangle points that form the box (if ...
8
votes
2answers
1k views

PostGIS raster value of a lat/lon point

I have a tiff raster in my PostGIS 2.0 database. I want to get the value of the raster at a specified lat/lon point. I have: postgresql-9.1 postgis-2.0-svn with raster support a raster imported ...
0
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0answers
81 views

Arcgis custom spatialreference and geolocation problem

I have a tiled map service layer that has custom spatial reference. This is url of map. Spatial Reference: ...
0
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1answer
108 views

Defining a WHERE clause from a subquery for a query to create a handy view

It is about my implementation from an answer of this question. It is more an postgresql issue than a GIS issue, whereas it is about geometries and spatial queries. I want to create a view from the ...
1
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1answer
288 views

Aggregate points with same values to polygons

I have a shapefile with 2M measurement points (each measurement point has a resolution of a 1/10). How can I aggregate points around each other if and create polygons out of it? They do not have to ...
2
votes
0answers
81 views

(Solved) Near/Spatial Join pick the wrong polyline segment as closest [closed]

I have a set of points near a street centerline. I need to find the perpendicular point on the street centerline, and use their x y instead of the GPS information of the original points. I tried Near ...
7
votes
4answers
486 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. ...
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votes
1answer
271 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
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2answers
131 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
606 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
133 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
118 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
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0answers
53 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
5k 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
55 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
276 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 ...
4
votes
1answer
390 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
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0answers
29 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
66 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
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0answers
39 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
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3answers
764 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
163 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
139 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 ...
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0answers
23 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
495 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?
3
votes
1answer
60 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
895 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
66 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
197 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
707 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
135 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
318 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
43 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
81 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
161 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
237 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
143 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
91 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
490 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
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0answers
37 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
100 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
101 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 ...