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

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3
votes
1answer
320 views

How to connect particular sets of points with (poly)lines?

I think my problem is quite easy to be solved by the most postgis-users, but i am a bloody beginner: i have a timestamped point-table representing GPS-tracked places of different cars. To distinguish ...
3
votes
2answers
1k views

Create point to a center of polyline

I'm trying to create a points in the middle of polylines. The data is now in the form of shapefile. Is there an easy way to do this? Cheers, Sanna
5
votes
1answer
415 views

adding multiple points to a linestring in PostGIS

Though a newbie to PostGIS, I'm having trouble solving something that I think should be farily straightforward. I have two linestring tables, both consisting of simple, 2-node line objects: one has ...
8
votes
2answers
734 views

How to add vertices to existing linestrings?

If I have Linestring(1 2, 1 5, 1 9) and a Point(1 3) Is there any function that can merge linestring and point preserving the order so output would be: Linestring(1 2, 1 3, 1 5, 1 9)
4
votes
2answers
444 views

ArcGIS: Rapid digitizing of Point Data

I have several big maps with a lot of points that I have to digitize. All these Points have different Values (depth in Meter, double) and will be stored in 1 Shapefile. Is there a way to speed up my ...
3
votes
1answer
96 views

Plotting pixels on a map image

I've got a list of some hundreds of latitude/longitude pairs close to each other (within a country). I want to create an image with a map, and circles overlaid around these points. Basically, what I ...
0
votes
1answer
257 views

Vector data(point) is drawn in wrong place on map (OpenLayers)

I need to show a map (world map, used default OpenLayers WMS) and one point on it (with events like onhover, etc). Here is my code: var options = { ...
6
votes
1answer
345 views

How to draw shapes with highest possible decimal accuracy

I am trying to read input of lat and long to draw the shape based on condition.The input is standard array of lat and long with 15 decimal accuracy. I am realizing - I am loosing some decimal accuracy ...
3
votes
2answers
2k views

Compute Angle of a line in conventional bearing

I am trying to compute angle between two lines (line segment) using ESRI (ArcGIS, JS) in conventional bearing (Eg: N29'E) I am using Add Toolbar to draw a line segment where point A is a fixed point ...
10
votes
2answers
403 views

How to identify and simplify point clusters with regard to time in PostGIS?

I just started to work with spatial databases and I want to write a SQL(PostGIS) query for automatic generalizing of raw GPS-tracks (with fixed tracking frequency). The first thing I am wokring on is ...
3
votes
2answers
515 views

How to create polyline feature from two input points by following/tracing another polyline?

I have a list of things each have two grid references, start and stop points. I can turn these into points and join them with polylines. But what I need to do is have the lines that join the points ...
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 ...
6
votes
2answers
2k views

How can several vector layers have different controls, using Openlayers?

Using openlayers I have two vector layers. One layer is called lineLayer consisting of vector lines, and the other is called pointLayer consisting of points. When I hover on the lines I want to be ...
0
votes
1answer
229 views

What is the fastest way to identify the two nearest linestrings using PostGIS?

I want to be able to identify the closest roads to two points that are generated through geocoding (a start and end address). The points will likely be near a linestring. Two approaches that I have ...
3
votes
1answer
485 views

Can I move points by editing x/y in attribute table?

Im new to QGIS and I just cannot figure out how to do this one hopefully simple thing: I have a bunch of points in shapefile and i need to move some of them around by hand / coordinates. I've ...
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 ...
4
votes
1answer
3k views

Arcgis 10: Point layer, polygon line layer, draw points to the nearest polygon point or other nearest line?

I have been using arcGIS for a while now but I often get frustrated with it :( I have version 10.0 arcGIS and I'm have two layers 1) Point data (building locations) 2) a polygon shape file (outline ...
4
votes
1answer
835 views

How to automate the drawing of polygons (square) around a number of points in QGIS?

In QGIS (or alternatively any other scripting + GIS stack), how can I automate drawing a 100km x 100km square around a number of points, with the point being dead in the center? I'd need to loop ...
1
vote
1answer
746 views

create buffer around locator-derived point

I am trying to create a buffer around a point derived from a locator search, using this example: http://help.arcgis.com/en/webapi/javascript/arcgis/help/jssamples_start.htm ..but I am getting no ...
2
votes
1answer
811 views

How to design markers - raster or vector?

I have several layers that are point geometries. I am defining them custom markers symbols and such symbols have colors (red, yellow and green) to represent values. Since there are several of them in ...
4
votes
1answer
633 views

ArcGIS 10: convert labels to points

is there a way to convert labels, created by Maplex labeling engine to point features? In MapInfo and CAD software, it's possible to convert labels to points. Those point features include a text and ...
15
votes
5answers
15k 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 ...
2
votes
1answer
73 views

How could I assign point values to a raster stream segment?

I need to assign a point value in raster format to a raster stream segment, which contains the point. See bellow: The expected result is a segment, whose value is the point value. How could I?
1
vote
4answers
628 views

How to find the center point of MULTILINESTRING?

How to find the center point of MULTILINESTRING, which lies on the multiline?
1
vote
0answers
100 views

Esri ArcGIS plot point

I have created a java function to plot the points on the map, and I need to pass the x-y coordinates and the taskevent as the parameters. I would like to ask what should be the input parameter for ...
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 ...
1
vote
2answers
2k views

How to offset point perpendicular to line direction in PostGIS

I have a postgis table of points, that are sitting on road centerlines (I've linear referenced them). And the second table with road centerlines themselves. The point table also has a field roadid and ...
0
votes
0answers
443 views

How to do a spatial join if QGIS 1.8 keeps crashing?

I am trying to perform a simple spatial join (adding polygon data to points) in QGIS 1.8: target vector: points join vector: polygons take attributes of first located feature keep all records ...
2
votes
2answers
2k views

PostGIS convert geography(Point,4326) to GPS

I got a database with a column of type geography(Point,4326), the data contained looks like 0101000020E610000092E057F66EF73140930035B56CBD4840. How can I convert it to GPS coordinates?
5
votes
1answer
190 views

Given 2 LINESTRINGs with common point, how to extract common point?

I have 2 LINESTRING geometries. I know both share a common point. Using PostGIS for Postgres, what is the cleanest way to extract the common point? Example with illustration: How do I extract the ...
2
votes
1answer
375 views

How to create a point table from a remote csv file?

The current approach that I am using to load a csv file into a PostGIS enabled database on a server is the following: -- create table CREATE TABLE points( id int, lat double precision, lng double ...
4
votes
1answer
622 views

Is it possible to create a point within a Polygon (not a centroid)?

Is it possible (without writing Python code - sorry I'm not a developer) to create a point layer from a polygon layer but ensure the point is within the polygon? The ftools centroid tool is cool but ...
5
votes
2answers
5k views

How to calculate new point coordinates from distance and angle?

I want to calculate the coordinates of a new point. What I have: The source point coordinates, the distance (meters) and the angle For example: I want to create a point within 100 meters and 45 ...
7
votes
3answers
4k views

How do I retrieve start and end point coordinates with Python/arcpy?

How do I retrieve start and end point coordinates with Python/arcpy for a polyline feature class? I expect to pass a segment identifier to a subroutine and have it pass back start and end coordinates. ...
1
vote
2answers
563 views

Handling points in openlayers

I have a several hundred points that I am showing on a map. At the moment, my method of adding the points seems inefficient. I create an array using the following approach: var features = [new ...
2
votes
0answers
532 views

cant find point/polygon intersect using qgis (windows only)

below i describe the method i am using. i have 2 machines: 1 ubuntu linux, qgis 1.4 - intersection works 2 WIN xp, qgis 1.8 - intersection dows not work hopefully, someone will ...
6
votes
2answers
263 views

Why am I getting duplicate ghost points (features), i.e., one point in the feature class but two points?

When editing some of the attributes in a point feature class in ArcMap 9.3, duplicate labels started showing up. When I click on the point, I discovered that the point has duplicated itself BUT there ...
9
votes
4answers
2k views

How to filter wrong GPS points?

I have a database of GPS points. There aren't any tracks, only points. I need to calculate some value for every 100 meters, but sometimes GPS gave a wrong coordinates that lies far from real GPS ...
1
vote
1answer
516 views

Generating Point from Centroid of Polygon Error

I have a feature class of polygons within a geodatabase and I'm trying to generate points based on the centroid of the polygon using the Feature to Point tool in ArcGIS 9.3. However, I end up with ...
8
votes
2answers
1k views

How can I create random points along a polyline in QGIS?

I am trying to create random points along a polyline shapefile in QGIS. Basically, like the 'random points' tool in 'research tools' but for polylines instead of polygons. I have tried converting ...
3
votes
2answers
1k views

How can i select a polygon in MS SQL 2008

I am very new to MS SQL 2008. I got a task to select a polygon from the polygon layer by giving the X-Y coordinates. I already got the script for PostgreSQL for the same thing, but i need it for MS ...
1
vote
4answers
4k views

Prevent drawing of overlapping point symbols - ArcGIS Server/Javascript API

Is there any way in ArcGIS to prevent symbols from being drawn when they overlap each other? I know this is possible for Labels using Placement Properties/Label Weight, but I can't seem to find ...
2
votes
2answers
508 views

Where can I get a multipoint shapefile?

I'm trying to find a multipoint shapefile to do some testing for an application I'm working on, but I cannot seem to find one (and do not have ArcGIS to create one). Can anyone suggest a place to find ...
2
votes
1answer
851 views

Geometryutil, simplify polygon, querytask and query fault error

One of the tools in my app is to draw freehand polygons (counties) to show points (companies) in each county. Everything works great but if the user creates an intersecting polygon then I have a ...
1
vote
3answers
539 views

Divide Line Into Sections Using Points Offset from It

I have track (line) and milemarkers (point). Each point is offset by a different distance. Is there a way to find where each point would intersect the line if going perpeniduclarly out from the line? ...
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 ...
4
votes
1answer
536 views

Address or reverse geocode a point shapefile

I have a shape file that contains points. I want to do a reverse geocode and give these points an address. Can someone please help me?
3
votes
0answers
74 views

Adding points to represent non-chosen locations

I am looking for a way to set up a discrete choice model in ArcGIS for foraging behavior of individuals, in a grid of 15 locations. To do that I need a point for every possible choice they could have ...
4
votes
5answers
6k views

How do I create a line between two points with a common field?

Does anyone know how I could create a line between two points that have a common code? For example: I have the start and end point of a pipe as a lat/long for a network of pipes, each with a ...
7
votes
3answers
745 views

Creating raster or vector raster from DEM point file?

i have a point shape of 75.000 elevation points in a regular 5 m grid. We now want to create a polygon grid with the elevation points as "centroids". Unfortunately, all attempts to do so fail: I ...