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

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5
votes
1answer
48 views

How to group 10k points into closest pairs?

I was first faced with a problem of grouping 1000 pairs into unique pairs to minimise the total distance - since this was a small number I solved it using linear optimisation: Part 1 - Basic/Naive ...
2
votes
2answers
166 views

how can we save vector layer as a file in openlayers

Im using mapserver + openlayer for GIS API and im new to GIS. I'm done with drawing line, point and polygon features in openlayer. but not being able to save it in some shapefile afterwards i got to ...
2
votes
2answers
59 views

PostGIS convert point->raster->GeoJSON

My question is a follow up to Convert a raster to GeoJSON polygons in PostGIS I'm trying to accomplish querying point data from the database, and then turn that into a raster for calculating ...
2
votes
1answer
37 views

Polygon data to Point Feature Data

Using ArcGis 10.0. What I am looking for is a way to get point features that are placed in a polygon to have the same "Address" value. This is the same as the "Spatial Join" feature, however, I am ...
1
vote
2answers
348 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 ...
11
votes
3answers
12k views

Converting Polygon into single or all Points using QGIS?

I want to convert polygons into points using QGIS. I know how it's done in ArcGIS Desktop.
1
vote
1answer
23 views

Correct Projection for calculating centroids of a group of points?

I have a long list of points covering all of North America for which I would like to calculate the centroid (by grouping points based on the "Name" column). My approach is to take the WGS84 ...
4
votes
2answers
105 views

Oil and gas well symbology for geoserver

I need to symbolise an oil and gas well dataset in geoserver. I have the dataset symbolised in ArcMap using the standard esri well symbols. Is there an easy way to convert this esri layer file into ...
0
votes
1answer
212 views

CartoDB: How to I cluster by features? Is it even possible?

I have a set of points for a number of buildings in NYC. I would like to group those points into clusters per their respective neighborhood (ex: Chelsea, Upper East Side etc.). Each of my points have ...
0
votes
2answers
38 views

remove certain points from point shape file

I have a point shape files with 9674 points.The attribute column has three fields: X, Y and value. Out of these 9674 points, I want to remove 1700 points based on X and Y values (I know the X and Y of ...
6
votes
1answer
293 views

Is there a “Disperse Markers” tool for QGIS?

I am using ArcGIS, but either I would like to use QGIS and maybe want to switch completely later. A have a point overlapping problem, as a result of geocoding of addresses. I have not found any ...
2
votes
1answer
418 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
12 views

How to get (x,y,z) or pixel value from map in ArcMap by using Visual Basic 2012? [closed]

I want get point(x,y,z) or pixel value from map to Visual Basic 2012 directly in array form or send point (x,y,z) from Visual Basic 2012 to ArcMap 10.2.2.
2
votes
2answers
3k views

How to create a graphic point by xy value?

I have implemented this code to create point event layer by xy text file, however I'm wondering how to create a point graphic by xy value? This script draws point graphic by mouse down. When I ...
5
votes
1answer
396 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
808 views

How to do a Point to Polygon analysis with multiple variables in QGIS?

I have a database of almost 10k crimes, which are divided in to 10 categories and plotted on a map I also have a database of 12k addresses, which are also plotted on the map. I aim to perform a ...
0
votes
0answers
30 views

Newly created points disappears after saving edit session [closed]

So I'm trying to add two points to a new shapefile that I created in ArcMap. I created my shapefile from ArcCatalog. Once I create my two points with the Edit Toolbar, and click "Save edits", the ...
1
vote
0answers
14 views

Colliding labels for point features in QGIS

I have a layer (point features) containing various points of interest (POIs), some of them have the exact same location. I would like to map these POIs and add a label showing their names. However, ...
1
vote
1answer
29 views

GeoDjango - save two Point fields, one for geography and one for geometry

Most of the explanations I've read for geography and geometry seem to suggest that one must only use either geometry or geography, and that the only way to use both is to cast/convert between one and ...
2
votes
1answer
47 views

How to create azimuth raster layer by pyqgis?

I want to create an azimuth raster layer base of single point shapefile, for this I write below code that create a memory point layer that each point in memory layer is center of each pixel and have a ...
7
votes
4answers
4k views

How to extract POINT from a [LINE|MULTILINE]STRING

I'd like to create a vectorLayer in QGIS to display all the points that form a LINESTRING or a MULTILINESTRING stored in a PostGIS DB. I think that I need to transform all points of LINESTRING (or ...
6
votes
2answers
157 views

How to speed up this script in QGIS?

I am a new in PyQGIS, I want to create a Point layer from a raster layer. In table of point layer created, there is 3 fields by name of "X_coord", "Y_coord" and "Azimuth", each point in Point layer ...
0
votes
1answer
41 views

Select by Location using first points of polyline

I am trying to select a point from a point layer that intersect a polyline layers firstpoint and using arcpy. I am getting an error "ExecuteError: ERROR 000622: Failed to execute (Select Layer By ...
3
votes
1answer
28 views

Adding hover pop-up notes to map Arcmap desktop 10.3

I have a layer of points defining a variety of geologic features overlying a global map. I would like the user to be able to hover over a point and see a description of that feature. Hyperlinks ...
1
vote
1answer
31 views

Error when trying to plot legend for geom_point with ggplot2

Here's some mock code to go along with my problem: #read in libraries library(ggmap) library(sp) library(raster) library(ggplot2) #read in country shapefile, project, fortify for mapping with ...
2
votes
0answers
51 views

“Geometry cannot have Z values” exception in ArcGIS Engine

I'm trying to put a list of point features (selected points) into a new FeatureClass. but when I add them to my FeatureClass I get the "Geometry cannot have Z values." exception on the line ...
2
votes
4answers
1k views

Finding center point of MULTILINESTRING using PostGIS?

How to find the center point of MULTILINESTRING, which lies on the multiline? I am using SQL in PostGIS
0
votes
1answer
187 views

Try to load GeoJSON object with OpenLayers 3

I'm a bit new to working with OpenLayers 3. I'm trying to load a GeoJSON object in OpenLayers 3 but it display the center only point[0,0], which not even in my GeoJSON object, where I'm going wrong. ...
2
votes
1answer
481 views

How to obtain closest point of point over polylines layer in PostGIS 1.4 (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 ...
0
votes
0answers
29 views

GeoServer SLD Filter rule before PointStacker transformation

I'm trying to apply a filter rule in an SLD, before applying the GeoServer PointStacker transformation (which groups points that are too close to distinguish their icons). This transformation is ...
1
vote
1answer
22 views

inserting value from raster into overlaying point field

I am using ArcGIS 10.3 for Desktop. I am using an etopo bathymetry map and would like to determine the depth of ~50k points in another layer. I am sure there is a simple tool for this but I am ...
24
votes
5answers
36k views

How do I create point features with exact coordinates?

How do I create point features with exact (manually entered) coordinates in QGIS? I get precise GPS coordinates from a survey team which I need to add to a point layer. What I want: -Add point, type ...
0
votes
1answer
30 views

Changing default point symbol?

I am trying to change the default point layer symbol to a set one. For example I have a fire hydrant point layer that is represented by a default point symbol when I import it into my map. Is there ...
1
vote
1answer
370 views

Invalid join selectivity error in postgis 2.1.3

I have 2 tables, one for points and one for polygons. I want to find points falling within theese polygons, so I quered: select p.id, l.id from points p inner join polys l on st_contains(l.geom, ...
0
votes
0answers
3 views

Retaining Raster Point Data Using wms [duplicate]

I have a single band raster being served via geoserver wms. When I view the raster through geoservers built in openlayers viewer I get different point value results than if I ask geoserver for a ...
1
vote
1answer
35 views

Finding and merging lines that touch in PostGIS?

I would like to select and merge segments that touch like in the image below. My table contains single segments with their own id (shown in the figure), I just want to isolate single "group" of ...
3
votes
1answer
58 views

Is it possible to create points that represent lines in QGIS 2.8.Wien?

I want to create points to represent lines from a line layer. This is similar to creating points to represent polygons. Does anyone have an idea on any useful plugin or the best way to do this?
1
vote
0answers
13 views

How do I generate a sampling path by numbering points?

I need to number points from left to right and then the next row of points the numbering must continue from right to left, then again from left to right the row thereafter - and so on, and so on. ...
2
votes
2answers
67 views

Extending line by adding point at end of it using QGIS?

I'm using QGIS 2.8 to modify a line. I need to add a point on one end of this line, and then move this new point further away, leaving the original end point in the same place. I can manage to create ...
3
votes
1answer
41 views

Rotate symbols perpendicular to line angle (QGIS)

I have lines representing curving streams and want to angle symbols at various points on the streams so that they are perpendicular to the angle in their particular locations. What QGIS seems to do ...
2
votes
0answers
25 views

Adding attribute data together within multiple polygons in QGIS? [duplicate]

In QGIS I have two vector layers, the first is a set of polygons and the second is a series of points. Each point has a numerical attribute associated with it and is located within one of the ...
2
votes
1answer
588 views

How to generate random points with minimum distances between points in multiple polygons

I am looking to create random points for a random stratified survey. There are three different categories being surveyed; for each, I have a single shapefile, each containing a number of polygons. I ...
2
votes
1answer
48 views

Selecting features of vector layers based on another vector layer using QGIS?

I am using QGIS 2.12.2. I am using three vector layers (point, polyline and polygon shapefiles) of the region of interest. Any advice in making the selections from one dataset based on the other ...
1
vote
1answer
68 views

How do I assign elevation labels to a custom set of points in QGIS?

Im trying to create topographic surveys using georeferenced images from a drone and a DEM/orthomosaic which has been created using Photoscan. I've managed to create contours and label them with ...
0
votes
2answers
49 views

Point feature plots in wrong place in QGIS?

I am using QGIS 2.12 on Mac OS X Yosemite 10.10.5. I have a single point with given latitude and longitude. I want to create a new vector layer (shapefile) which will plot one point on the map ...
0
votes
2answers
176 views

Distance between points along polyline ArcGIS for Desktop?

I'm using ArcGIS 10.3 (Desktop), and I'm trying to measure the distance between points following a path determined by a set of polylines. Hand measurement is not a viable option-- there are ~7500 ...
1
vote
2answers
206 views

Points on Map overlapping/covering city and town names

I have a map with many points, these points map incidences of landmine accidents in Colombia. There are thousands of points and cover up parts of city and town names, in some cases the entire lables ...
4
votes
1answer
42 views

Is it possible to locate a specific marker point on a raster using python and use that location for georeferencing

I have several scans of the same map, which I would like to georeference. I can not use arcpy.WarpFromFile_management(...) as the rasters are slightly different due to scanning. Is there a ...
0
votes
1answer
33 views

Connecting two points in ArcGIS for Desktop?

I have two types of point shapefiles. These two points are linked with another attribute table. Each Point from column A is linked to single/multiple values in column B. Each of these object_IDs have ...
2
votes
1answer
55 views

Trouble adding proportional circles on top of symbolized polygon in ggplot2 map

Data: Zipped ea.ml1 shapefile can be found here, and the country outline can be downloaded here at the GADM site. I've been using the Ethiopia ESRI shapefile. Branch locations are here. Per the ...