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

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2
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0answers
44 views

How to show coincident point with different symbology in webgis?

our team have develop an webgis using ArcGIS silverlight API 3.1 .we have some points in database.These points are save in a table in sql server 2008R2 not in Geodatabase.The points have same ...
0
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1answer
86 views

Multiply point values by raster values

I have a point shapefile containing elevation values in the id field. The shapefile is overlaying a raster layer of the topographical slope. Is it possible to multiply the elevation value of each ...
2
votes
3answers
145 views

How to identify concentrated areas with multiple point values to produce a “heat map” appearance

I have roughly 1.6 million points statewide with values ranging from 1 - 4. I'm looking to identify concentrations of points based on their values (1,2,3,4). I know there are several different routes ...
1
vote
1answer
87 views

How to compare multiple spatial point patterns over a polygon

I have multiple point pattern distributions over the same region/polygon. Each point pattern distribution has different number of points. Here is an example of two spatial point patterns for the ...
0
votes
1answer
102 views

Produce line from components, length and angle

I have a CSV file, or point data file which includes information about line vectors which I have previously calculated. This file is outlined as such: x, y, dx, dy, length, angle(east_from_north) ...
1
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0answers
240 views

Splitting polyline by points using ArcGIS 10.2 for Desktop?

I have a layer containing a curved polyline and I would like to split it at multiple point locations, which I have in another layer. In ArcGIS 10.2, I can do this with the tool "Split Line at Point". ...
1
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0answers
140 views

WMS: point “pointer” symbol with offset - getFeatureInfo search area slight mismatch

I'd like to ask what ways there might be to adjust a point's getFeatureInfo search area so that it matches a "pointer" (i.e slightly offset) symbol. We are running GeoServer 2.2.0 (part of an Opengeo ...
0
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0answers
30 views

Statistics on matching point layers ignoring nodata values in QGIS

I have a large area and a street crossing this area. Both are vector point layers in QGIS. The large area contains -99 as NoData value. I already created the intersection of both as a new layer. I ...
11
votes
2answers
815 views

Moving points onto lines (~neighborhood)

I do have two vector layer, of which one is a point layer based on "events" by remote sensing and the second one is a line layer from local research. In my case these are earthquakes and tectonic ...
3
votes
2answers
232 views

How to convert a point layer to a raster grid that shows the frequency of points per cell in QGIS

I have a point layer that shows the distribution of a species. Is it possible in QGIS to convert this point layer to a raster grid in which the value of each cell corresponds with the amount of points ...
2
votes
1answer
653 views

Better way to get raster values for a large number of point features?

I have several projects with tree point features (SpecialStatusSpeciesPoint) that contain up to 2,000,000 records. I am trying to record tree height (Hgt) and base elevation (BaseElev) values, based ...
1
vote
1answer
50 views

QGIS hides few graduated points after reopening project

I have a strange problem in QGIS 2.2 (problem is also present in QGIS 2.1). When I add a point (shapefile) layer, apply graduated style and change point size, everything looks fine. Then I save ...
0
votes
1answer
458 views

Geodjango: Using Lat / Lon to Buffer from Point

I want to have a radius based distance search. To do this, I want to create a buffer around a point object so that I can filter objects that are inside this buffer, a method that I learned based on a ...
0
votes
0answers
52 views

Split polygon into four with respect to single point

Some days ago one of my colleague came to ask me a query related to Geometries. The situation is as....There is one Polygon(suppose a city polygon) and there is one point(suppose user's current ...
0
votes
1answer
38 views

Create Random points

I have polygon with an attribute which has numbers populated in it. I would like to create random points for each of the polygon depending on the attribute. How could this be done ??
3
votes
2answers
648 views

Converting Vertices of Polylines and Polygons to Points and Maintain Attributes

I'm pretty sure someone has done this before, but I'm having no luck. I'm using ArcGIS Standard version 10.2.1 and I want to convert all the vertices of a polyline or polygon to points. Essentially, ...
0
votes
2answers
444 views

Find maximum and minimum value of points within a polygon buffer?

I have a series of 500m buffer zones along a polyline. I also have a series of points following the line, each point represents a 10m x 10m cell. I calculated the values of a field in each point known ...
1
vote
2answers
266 views

How can I group Points to make polygon via Python

I have an array of coordinates Point= [lat,long] ListPoint= [[38.203655,-76.113281],[38.10,-76.12],..] I wanna make a polygon that contains all these points ? There is a project developed by ...
2
votes
1answer
89 views

Using Python to create new point location based on various azimuth and distances

I have a feature class with thousands of points. In the same table with these point locations, I have two additional fields. One for azimuth, and one for a length (or distance) to move along that ...
0
votes
1answer
62 views

Associate points with polygon QGIS 2.2

I want to associate a point layer with a polygon layer so that I can do zonal statistics. In the image below, the polygon layer represents roughly the metro area of a certain city. The point ...
0
votes
0answers
55 views

Reducing point numbers in a certain area

We have a list of poi data in our database(Access mdb db), and we have a web service which serve data by a specified BoundingBox. However we found that the returned points are too close to another at ...
2
votes
1answer
97 views

Averaging XY points locations if in close proximity automatically over a large dataset in R

I have a point dataset (XYZ values) containing a few million points covering a 5km x 5km extent representing maxima locations. However there a great deal of these points which exist in 0.5m of others. ...
0
votes
1answer
84 views

Point-sampling rasters using R? [duplicate]

I need to be able to sample many raster files (imported from GeoTIFFs) using a previously defined set of spatial points, using R. What's the best way to do this?
0
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0answers
78 views

Pointstack with different count-1-symbols / SLD / GeoServer

I try to use the pointstack sld to visualize my data at different scales. I used the example from http://suite.opengeo.org/opengeo-docs/cartography/rt/pointstacker.html, and everything is fine. ...
0
votes
0answers
45 views

How to create a point representing a polyline?

How do I convert a line (usually 2 vertices but can be more) into a single point in QGIS? I did it a couple of years ago using a build-in tool in ArcGIS 8 or 9 I think but have no idea how to do it in ...
8
votes
1answer
289 views

How can I transform polylines into points every n metres in PostGIS?

Question in pretty much the same as this, but I need to use PostGIS. I have a number of polylines, and want to trasform them into points every n metres along these lines. edit: Thanks a lot to ...
1
vote
2answers
44 views

Creating Many Uneven Buffers

Qgis 2.2, Windows 7 I am looking to create buffers around city lights (the raster). Currently, I have simple polygon buffers around the point layer (oecdminusa), but this is not accurately capturing ...
0
votes
0answers
19 views

Point in Linefeature build through specific topology rules

i want to build Lines from Point Features following different topology rules (that lines aren't like randomly build, but how i should be following the extent from other polygons for example.. when ...
0
votes
1answer
180 views

Creating points based on coordinates in MapBasic

I am currently working on a MapBasic tool that generates start and end coordinates for a polyline layer. So far I have successfully populated 4 columns in a table (SX, EX, SY, EX) with coordinates of ...
4
votes
2answers
6k views

How to use Distance Matrix tool in QGIS?

I have a point data set. Now there are cluster of points based on a field. So I take out one such cluster which has points with same field.I want to find distance between all the points in cluster and ...
4
votes
2answers
214 views

How to speed up a query for nearest linestring to point data

I have processed a Strahler stream order layer with a lot of river linestrings (type: Multilinestring) and their corresponding strahler number (see information here). Besides I have a point layer. I ...
4
votes
1answer
86 views

How to find closest point without crossing obstacles?

I have a set of points and I'd like to be able to find the nearest point from another layer. The problem is that I need to find the closest point without crossing an obstacle (such as a river, ...
0
votes
2answers
331 views

GeoServer create layer from PostGIS (data type point)

(Several days ago a user on gis stackexchange suggest that I should use OpenGeo (I was using geojson before). I succeed at what I was doing at that time, but now I have a different problem.) I was ...
1
vote
1answer
85 views

Counting points in a raster

Is there a way to select points in a raster dataset by raster classification? I have a floating point raster created from the points, classified into 4 ranges by standard deviation. I want to find out ...
0
votes
0answers
33 views

Multiple Centroids within a dataset based on distance

Is there a way that we can find out the centroids of clusters within a dataset while differentiating one cluster from other based on distance not on any attribute value. The dataset is present in ...
0
votes
2answers
893 views

Using NetCDF for point time-series observations?

I have a large growing dataset of water and climate observations for several years in regular hourly time-step. The number of locations is cca. 1000 locations with latitude, longitude coordinates. At ...
1
vote
2answers
72 views

Finding routes in which more than one car passed (gps data)

I'm using ArcGIS 10.1. I have point GPS data of routes of several cars over a few days, and I want to find only the routes where more than one or two different cars passed through (Each GPS points ...
0
votes
0answers
35 views

Can't get X coordinate of PointM in PostGIS

Here are two queries, and I can't understand how to filter points if st_x does not work in WHERE clause. select st_x(geom_merk), st_asewkt(geom_merk) from road_density limit 5; ...
1
vote
2answers
170 views

QGIS 2.0 Automatic generation of a vector layer out of a point layer

I am an environmental engineer and the aim of my QGIS 2.0 project is to visualize the results of a sewage water system inspection. In a first step I included the hoppers from a csv file and added a ...
0
votes
1answer
54 views

Get all points with in some range of a point (or range of point)

I have got a list of points and a fixed range (10m). So what I have to do is for each point I have to find all the points present in a table with the 10m range of the given point. For example: Let ...
0
votes
2answers
103 views

How to get information about only one data point?

I have a vector-point shapefile. The data are not dense (about 1 x 1 degree). Lets say that every point includes value of average wind speed. I would like to create a interactive web-map so that ...
2
votes
1answer
59 views

Identify geographic location to points

I am quite new in QGIS and I really need your help. I have a map of Kenya divided into 68 districts and I have coordinates of 30.000 schools. The points have one variable besides the latitude and ...
1
vote
1answer
105 views

Adding XY coordinates from a point feature class to a one to many related table in ArcGIS 10.0

I have a point feature class with a one-to-many relate to a table. I would like to add the XY coordinates of each point in the feature class to the related table where the ID field matches. Of course, ...
3
votes
1answer
153 views

Select points approx. 2000 metres from another point along a river?

I have a series of points representing a river network (See Image Above). Each point contains attributes on Latitude, Longitude, Z value and Length calculated using flow accumulation. The river ...
5
votes
1answer
156 views

How many GIS projects deal with just basic “putting markers on a map”?

Is there an academic paper or conference contribution, where someone estimated how many GIS projects actually deal with only a very basic usage of GIS data? Something equivalent to the infamous "80% ...
0
votes
0answers
28 views

Creating a point layer from lat/long coordinates [duplicate]

I have a spreadsheet that lists the lat/long coordinates of several locations I wish to map. I would like to produce a geocoded point layer in QGIS. How do I do this? Thanks!
2
votes
1answer
605 views

Problem creating point shapefiles programmatically using python in QGIS 2.2

I am trying to create a point shapefile in the memory buffer (for a temporary label) and then zoom to the extents on this buffer. The working (in version 2.1) test code for this is: def ...
2
votes
1answer
87 views

How to find the polyline's ID connecting two points in ArcGIS 10.1?

I have an ArcMap (*.mxd) file with several layers including a point layer and a polyline layer. The points are connected by polylines in the polyline layer, and I wish to know how to list the ...
2
votes
0answers
50 views

What is an Orphan point?

MY apologizes about the next doubt, but I can't understand what is an orphan point. I am using QGIS with a module to apply the Linear Reference System (the module is called "LRS"). During the ...
0
votes
3answers
418 views

splitting a lines layer using points

I'm looking to accomplish a similar task to this thread: How to split a line at point positions? Using QGIS and the Processing and GRASS toolboxes available, I'm looking to split a vector layer ...