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

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3
votes
1answer
179 views

How can I create an DEM from Point-Data

my boss gave me a small 3D-point-shape-file and asked me to make an DEM from it, wich I should put together with an older DEM of the same site, wich was made with Surfer. I created a raster-layer from ...
3
votes
1answer
167 views

QGIS - Calculate distance between a point layer to n nearest polylines

In QGIS I am trying to calculate the distance from a point layer to a polyline layer for the n nearest polylines. I have figured out how to calculate this distance to the centroid of the polylines ...
8
votes
6answers
17k views

ERROR 000212: Cannot create XY event source Failed to execute (MakeXYEventLayer)?

I have a csv file that is 133mb in size and has over 1.3 million lines of data. Each line of data has its own lat/long and I was wondering what would be the best way to display those points based off ...
3
votes
1answer
150 views

How to find mean coordinates of a cluster of points from a point layer in QGIS?

I have a set of coordinate points. The points are distributed in such a way that some points are clustered around a specific area. There is an option to find out mean coordinates(s) of the whole point ...
4
votes
1answer
184 views

Creating a point corresponding to the maximum elevation of a DEM [duplicate]

I am wondering how can I create a point corresponding to the maximum elevation value of a DEM. I mean, from the DEM I can easily get the maximum elevation. For the sake of a viewshed analysis, I would ...
1
vote
0answers
29 views

How to get attributes from line-polygon where points are snapped on, into the point-layer?

I have a SQL Server spatial table with point-objects, the points are set by snapping onto a line SQL Server spatial table. so the points are georeferenced on the line. How can I get the attributes ...
3
votes
2answers
2k views

Update point coordinates in QGIS after manually moving locations in edit mode

I have imported point coordinates from a database, but I need to manually adjust a lot of the locations. Is there a way for QGIS to automatically update the point locations in the attribute table ...
7
votes
4answers
2k views

How to create different diameter circles round points?

I want to map a tree survey. I am thinking that I will plot positional points of the trees and then add other data like tree type etc. to the attribute table later. Is there a way I can have an ...
0
votes
2answers
128 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 ...
7
votes
2answers
3k 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
votes
0answers
62 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
377 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 ...
3
votes
1answer
294 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 ...
3
votes
4answers
2k 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
65 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 ...
6
votes
3answers
1k 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
6k 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
27 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 ...
3
votes
3answers
729 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 ...
6
votes
2answers
331 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 ...
1
vote
1answer
44 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 ...
1
vote
2answers
518 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 ...
3
votes
1answer
6k 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
0answers
50 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
433 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
votes
0answers
284 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
votes
1answer
34 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
vote
1answer
36 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") ...
5
votes
0answers
160 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
33 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 ...
1
vote
0answers
146 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
48 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 ...
3
votes
1answer
209 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
67 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 ...
4
votes
1answer
1k 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 ...
2
votes
1answer
150 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
154 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
436 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
1k 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
44 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 ...
1
vote
1answer
71 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
66 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
148 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
97 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 ...
3
votes
2answers
119 views

Determining closest representation of polygon as collection of points+radii

Have a bit of a tough question, which I realize there may not be an easy solution to. Figured what better place to ask. I'm attempting to transform a polygon into a series of arbitrary points with ...
2
votes
1answer
285 views

Getting null values using Point sampling tool in QGIS 2.0.1

I would like to obtain the information of a raster layer at some points. Apparently the Point sampling tool does the job. I have used this tool, and all the raster values extracted at specific points ...
0
votes
0answers
42 views

Reading Points as PolyLines

I'm currently developing an Android app where I need to show some information on a map, which is stored as Shapefiles (.shp + .shx + .dbf). I noticed that when the shapefile is opened in QGis, a nice ...
1
vote
2answers
751 views

Creating density map from point data?

I have point data, where one point represents one 1 storm water outfall, looks like this: (point data is across all of Long Island, New York). I am having a bit of difficulty finding the best tool ...
0
votes
1answer
95 views

TIN file to a POINT file

I have some bathymetry data in TIN format; I am able to open this in arcmap and view the terrain. However I need to use this data within a simulation framework called Delft3D, which needs the ...
0
votes
0answers
49 views

QGIS Rasterization of points

I have a point vector layer and want to make it a raster. Trouble is that many points are very close to each other, so unless I specify a very small resolution of the raster cells, likely several ...