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

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2answers
43 views

Curved Arrows showing trade ARCGIS 10.2 [duplicate]

I have 10 points that represent the centres of countries. I want to show with arrows the flow (some kind of trade) from one country to another. The way that my table of attributes is constructed is ...
6
votes
2answers
2k views

QGIS calculate distance of point along a line

I have a polyline (movement path) and points recorded along the line. I would like to calculate for each point the distance along the line in Quantum GIS. I hope for a result which will add a new ...
0
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0answers
13 views

export qgis point symbols per feature

I am currently trying to export the drawn symbol in a QGIS map for a webmap. The current approach is to extract the properties: if i.rendererV2().dump()[0:6] == 'SINGLE' and i.geometryType() == 0: ...
2
votes
2answers
321 views

How to find the nearest single point?

I have two shapefiles containing each one set of points, set A and set B. One set is my random selection (set A), the other is a list of communities (set B). For each point of the random selection ...
2
votes
1answer
49 views

ArcMap - Display direction of points

I imported a few geotagged images and created a points shape showing their locations (or more accurately, the location of the camera) with the "Geotagged Photos to Points" tools. The attribute table ...
2
votes
4answers
1k 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 ...
1
vote
1answer
36 views

Looking for information on methods or algorithms used to calculate centroid from polygons across software

Looking for information on methods or algorithms used to calculate point centroids from polygons across software. ArcGIS uses a "gravity model" but can someone point me to the math or a paper on the ...
2
votes
0answers
36 views

Point sampling along a pole-wrapping coastline with PostGIS

I am working on a task that requires me to get sample points every 1000KM along coastlines, and have run into a problem with Antarctica. From what I can tell, it seems to be an issue with the use of ...
6
votes
3answers
894 views

Adding “noise” to overlapping X,Y coordinates so no longer in EXACT same place?

I have a series of points representing animal observations. Many of them overlap, having the exact same coordinates, and this is causing me trouble when I want to run some analytical tools which ...
5
votes
6answers
4k views

How to represent several points with same coordinates on map? [duplicate]

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 ...
1
vote
0answers
25 views

Routing and OpenLayers: How would you connect a point to another through a 'road' node? [duplicate]

So my question is in a routing application,probably using osm as base layer, how do I get a line-string that goes through the road and not directly from one point to another? Is there any ...
0
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1answer
144 views

Get points along a polyline at defined distance c#

I need to store into my array the points along the polyline at each defined distance. Example: The Polyline length is 50m, I set the interval to 5m. I have to store in the array all the points along ...
1
vote
1answer
213 views

Split a line feature using nearby points

I have a line shapefile and a point shapefile, and the line has its own segments and its attribute table, the point shapefile has points near the line above, not on it and the close ...
3
votes
3answers
596 views

Performing join on simultaneous spatial and attribute criteria in ArcGIS for Desktop?

I have two point layers and want to perform a spatial join on nearest distance. Normally it is easy with ArcMap. But now I have a restricting condition on the spatial join. The restriction only ...
5
votes
3answers
152 views

Normalizing point cloud data

How I can get Digital Height Model (only object heights, DSM - DTM = DHM)? Many applications can do this, but they convert it to GRID or TIN format. I was wondering if it was possible to keep the ...
4
votes
1answer
234 views

QGis 1.8 fails to rotate point geometries with rule-based style

I have to do some visualizations in QGIS (1.8.0) and up to now I've been very happy with the new Dialog "Layer Properties -> Style", using the rotation-field to rotate Point-Geometries visualized by a ...
3
votes
2answers
60 views

Analysis of lines in a point in QGIS

I have 33 layers, 1 with points and 32 with lines. I want to extract/highlight the points where more than one line is intersecting. I have tried with buffers but I'm not getting anywhere.
1
vote
1answer
35 views

How to find ID's of nearest stations (points) in a specific radius

I am using ArcGIS 10.0 and I am doing rainfall data analysis. I have a single layer including more than 1,000 stations (points) and I need name (STATION_NO) of neighbor stations in more than one ...
2
votes
1answer
290 views

Postgis 1.4 - Obtain closest point of point over polylines layer (without st_ClosestPoint)

I´ve got a polylines layer (pipes) and a points layer (valves) and In Postgis 1.4 I would like to obtain the closest points but exactly on the closest polyline. In other words, i need to locate each ...
1
vote
2answers
47 views

Avoiding R for windows gui front-end has stopped working error?

I am trying to load huge number of points (shape file) in R. But when I load it, the program displays following error message and just stops. "R for Windows GUI front-end has stopped working" My OS ...
2
votes
1answer
4k views

Making POINT from longitude/latitude coordinates in existing table using PostGIS?

I would like to make a POINT using the longitude and latitude columns of an existing table. Here's a link to the documentation of ST_MakePoint. Here's my table: CREATE TABLE sysinst.bio ( oid ...
1
vote
2answers
202 views

Draw line between points from multiple datasets

I have 2 point datasets and want a tool or script to draw a line between all points in one dataset to all the points in the 2nd dataset. Is it possible? I have tried ESRI "Point Distance" and ...
1
vote
0answers
68 views

Spatially join points to polygons in arcGIS

I am trying to join a point feature class to a gridded polygon feature class in arcGIS so that all the points are matched to the grid cell that they fall within. I would like to end up with an ...
2
votes
1answer
42 views

Performing Point Distance analysis using Basic level license of ArcGIS for Desktop?

I am using ArcView Version 10.1 and I need to perform a point distance analysis like: What is the distance from A to B-Z, B to A-Z, C to A-Z, etc? What are the steps that I take to do this?
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0answers
39 views

Using Geoserver

I am new to GIS and interested in using Geoserver. I have had a look at tutorials and read some books on this but still feeling clueless. I intend to use C# to accomplish some tasks eg, plot points on ...
2
votes
1answer
108 views

Converting set of points to polygon using C#?

I want to convert a set of gps ponints to polygon.I used a simple loop to convert it to a WKT and than used makevalid() in sql server and save it in a gemetry column in databasae.Is this way right?or ...
0
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2answers
172 views

How to extend polylines to the nearest point

Hi could anyone tell me a way of getting my polylines to search for a point within a certain number of meters of their start/end points and extend to it? edit: There was some broblem uploading a ...
0
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0answers
94 views

Can't zoom to feature from Datagrid with ArcGIS API for JavaScript

I have a find task in my application that returns features that are points, lines and polygons. I can get the search to populate the datagrid but I am having problems with my onRowClickHandler ...
0
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1answer
16 views

How to convert 3d profiles to points in ArcGIS 10.1

I have created some 3d profiles using the Interpolate Line button (in ArcGIS 10.1). Which looks like: I would like to convert these lines into points and in order to do that I am under the ...
1
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1answer
28 views

Point input for polyline not acceptable?

Input QgsPoint(s) are returning an error in a Polyline creation routine. Any clues?! processing.runandload("qgis:polygoncentroids", Base, "memory:CenterNode") ...
12
votes
4answers
3k views

What is quickest way to select polygon by point in ArcGIS 10 using ArcPy?

I keep thinking that I must be missing something, but there does not seem to be a tool in ArcGIS 10 to select features (in particular polygons) from a layer at a point (X,Y) location via ArcPy. The ...
1
vote
1answer
94 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 ...
4
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0answers
45 views

How to compare two sets of points in QGIS?

I have two point layers with XYZ data; one set are points measured in the field and the second set is a Lidar data set. I want to check the accuracy of the Lidar in comparison to the measured data. ...
2
votes
1answer
27 views

finding the nearest point outside a series of geometries

I have db with a very large amount of geometries (circles), most of them overlapping. I'm trying to come up with a way to find the nearest point (from your current location) that is not within any of ...
0
votes
2answers
220 views

Create multi-line from point in PostGIS

I'm working on an old table where polygons are stored as points. Now, I want to migrate these points to PostGIS and store them as polygons (or multi-polygons). The table structure is as follows: ...
1
vote
0answers
45 views

OpenLayers - Add points at vertices of line while drawing line

I would like to create points while I draw a line on my map in OpenLayers. That is, at each vertices of a line and at the end points there is a shape like a square, circle, or diamond. I have this ...
3
votes
1answer
22 views

Deriving coordinates from Application.Display or MxDocument.ActiveView in ArcObjects?

I've found two possible ways of converting a MouseEventsArg's coordinates to the coordinates of the current map: The first is taken from a snippet included with ArcObjects: protected override IPoint ...
2
votes
0answers
33 views

How to Interpolate very large datasets in QGIS

I am working with a very large set of point data, (XYAttribute) which I wish to display as a raster. I've been using Interpolate, this is successful but very slow. I have other programmes that simply ...
3
votes
1answer
75 views

Find the closest line vertex from the linestring using PostGIS

How to find the closest line vertex from a linestring? ST_ClosestPoint will give a point which is not from the linestring.
2
votes
1answer
61 views

Representing multiple attributes of single point feature with icons?

I always wondered if there's a way to represent using an array of various icons multiple attributes of a single layer containing point features. For example, think about a point feature with these ...
3
votes
1answer
958 views

How does Flow Mapper Plugin work?

I downloaded the Flowmapper plugin for Qgis and I can't seem to find any information on how it is supposed to work... Also the text seems to cut-off and not fully showing for the input fields so I'm ...
1
vote
1answer
60 views

QGIS 2.4 Layout View pdf/raster file export moves points

I created a map, using a google basemap (openlayer plugin) and imported a table as a csv file (containing a name of a city, latitude, longitude for wgs84 and a row named "amount"). It displays ...
2
votes
1answer
51 views

Delete duplicate polygon nodes with PostGIS

I'm trying to delete duplicate nodes from a shapefile with QGIS, but after running the tool to delete it, nothing happens and shows the same errors. I thought that maybe importing to postgis could be ...
3
votes
2answers
158 views

How to automatically draw lines with a given angle from one single point in qgis 1.8?

I'm new to qgis so please be patient. I need to draw a bundle of lines all originating from the same point and with a 10° angle between each line (e.g. lines bearing at 0,10,20 ..90..110..220..350). I ...
2
votes
1answer
746 views

Getting polygon shapefile node coordinates and point order

I am trying to get the coordinates of each node of a polygon in QGIS. What I basically did is use the following tools: Vector -> Geometry tools -> Extract nodes Vector -> Geometry tools -> Export ...
0
votes
1answer
19 views

ValueError when instantiating LineString from a mix of tuples and Point objects

I'm new to Shapely, and tried instantiating a LineString object from a mix of tuples and Point objects like this: >>> LineString([Point(1,2),(2,3),Point(3,4),(5,5)]) I get the following ...
0
votes
1answer
33 views

WKT: What is the reasoning behind the concept of a POINT EMPTY?

In data formats like WKT and WKB, we have ways of representing "empty" geometries. That all pretty much makes sense: a "LINESTRING EMPTY" is a LINESTRING type with 0 vertices. Same with a MULTIPOINT, ...
3
votes
2answers
40 views

How to automate drawing a polyline from 2 intersecting datasets based on proximity?

I've been stuck on a situation recently where my company's data has to be integrated with another. Basically there are two point shapefiles comprising of >50000 points, and as shown in the image ...
1
vote
1answer
96 views

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

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
votes
0answers
78 views

Point features disappear when moved using QGIS 2.0

When I move, either by the node or the move function, a feature symbol on the map canvas, it simply disappears, not just the label, the whole thing. CTRL-Z brings it back. I'm using a MAC OS-X. I've ...