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

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53 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. ...
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0answers
44 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 ...
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2answers
43 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 ...
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0answers
18 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 ...
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1answer
104 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
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2answers
169 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 ...
3
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1answer
100 views

polygon from exterior points

How to convert points data to polygon, so as to form polygon from exterior point as shown above
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2answers
227 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 ...
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0answers
30 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 ...
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0answers
28 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; ...
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2answers
117 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 ...
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1answer
48 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 ...
2
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1answer
55 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 ...
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1answer
78 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, ...
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2answers
90 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 ...
1
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2answers
65 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 ...
7
votes
1answer
231 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 ...
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0answers
27 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
434 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
71 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
3answers
241 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 ...
3
votes
1answer
146 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 ...
3
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1answer
127 views

How to calculate distances between several points along network?

I have several points (bicycle share hubs), and I want to calculate the distance between each of them using a network. I want a CSV/XLS that has three headers: hub_id1, hub_id2, distance. I've ...
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2answers
137 views

How to get an indication of how points are spatially distributed?

Let's say I have a set of points and I want to get an indication of their spatial distribution. That is, if all points are at one location a possible return value would be 0, whereas if all points are ...
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1answer
11 views

GRASS Add Vector Point

I need to do a viewshed analysis using GRASS. I've got the DEMs loaded; and I simply want to input several (2-4) points (like 41.12345N, 122.34567W from GPS). What is the simplest, most ...
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2answers
99 views

Create line between polygon and nearest raster cell

I need to create a line between polygons (centroid) and the nearest cell of a raster dataset. The polygon and raster do not intersect. Each polygon has a UID. One cell can be linked to many polygons, ...
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1answer
50 views

Python script to select a point within a cell?

I have two features: points and grid cells (vector). I want to select a point within a grid cell (some cell do not have point) using python script and create a new feature layer with below conditions: ...
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3answers
222 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 ...
3
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0answers
77 views

Find the co-ordinates of tangent points and intersection of a curved line [closed]

I have a line with curves in it. Is there an easy way to extract the X Y values for the tangent points and intersection points in ArcMap 10.2.1? Hopefully my simple paint diagram clarifies what I ...
0
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1answer
68 views

Can I use Point as the geom type in pgrouting?

in my table i have the field geom(POINT, srid) and its populated, this table also have the source an target field witch is blank(just like pgrouting guide). I tried the function pgr_createTopology() ...
2
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4answers
153 views

Linking up GPS points taken from rail network

Bit of a newbie here, trying to work out whether any PostGIS functions can help with my task. Apologies in advance if my use of GIS terminology is not up to scratch yet. I have a large database of ...
3
votes
2answers
263 views

Line start and end nodes: determining what is a junction

I have a layer of points and polylines and want to determine which points are road junctions. I currently have all start and end nodes within 3m of my road network as a layer. However I cannot ...
2
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0answers
44 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 ...
4
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1answer
161 views

Create a point at the highest value in a raster ArcGIS 10.1

I am trying to find the location of the highest value pixel in my Direct Solar Radiation Raster. I can see the extent of the data in my raster but don't know where the highest value pertains to. Is ...
3
votes
1answer
91 views

How to map flood areas from a set of points containing surface and height of water?

I am working on the damages made by the typhoon Haiyan. I use QGIS 2.0 with extensions and toolbox, and MapInfo. I have vectors, rasters of the place. I want to map the flood area along the ...
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0answers
30 views

Creating contours from partial data set

Is it possible to create contour lines based on part of the points and not the entire dataset?
2
votes
1answer
165 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 ...
3
votes
1answer
127 views

How to horizontally align irregularly shaped point symbol to vector layer in QGIS?

Fairly new to QGIS and searching a method to graphically align my point symbols in the direction of the vector. The symbol represents a water valve in an irregular shape in close proximity to a vector ...
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2answers
89 views

Find nearest point (in file A) for every point (in file B)

I have 2 csv files both with 3 columns: variable, lat, lon. Let's call them file A and file B. File A has 100 values for variable (in this case city), File B has 100,000 values for variable (station ...
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0answers
53 views

Geoserver-WMS-problem when zooming point layer

I need help. I would like to have no blank(white) space between points when zooming in WMS geoserver. Any idea? Greetings, Andrew
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1answer
81 views

Can I “undo” buffering of a point layer in QGIS?

I have point layer, where each point is one tree, about 1300 trees in total. I made buffers around each tree, the buffer being the height of each tree in QGIS 2.0.1. My next step was to use Spatial ...
0
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0answers
342 views

Polygon to point conversion in ArcMap

I tried to convert polygons to point using Feature to Point under data management toolbox in arcGIS 10.2 (got it from uni. licensed). I got the point layer but it is not showing anything. I added X ...
2
votes
3answers
206 views

Can ArcGIS only merge two shapefiles each time?

I need to merge multiple point shapefiles (in the same directory) into one point shapefile. After inputting these shapefiles and merging it, I found the final output only contained the data from two ...
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2answers
273 views

TIFF/Raster to Point shapefile question

Apologies in advance if this question is incredibly basic, but I've been googling around and I just don't know where to start. I've downloaded some nighttime luminosity data from NASA, and the data ...
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2answers
181 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 ...
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0answers
82 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 ...
5
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3answers
302 views

How to visually sort the order of Points with QGIS, GDAL, …?

The following Points layer is the basis of a rendering in a Android application. Android allows to draw a shape from the provided points. I cannot use LineStrings. However, the order of points ...
2
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2answers
162 views

How to convert Point coordinates into CSV format?

The GDAL documentation describes how to convert a ShapeFile into CSV data. The layer create options (-lco parameter) allows to prepend the coordinates of Point features to the actual attributes ...
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2answers
87 views

What is the most efficient method to delete points?

I have a script that takes a point featureclass (FC) through the following workflow: Select points that lie within individual polygons From the selected points within each polygon, randomly subset ...
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1answer
100 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 ...