A geometric element defined by a pair of x,y coordinates.
3
votes
2answers
655 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 ...
2
votes
1answer
465 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
331 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
248 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 ...
3
votes
2answers
328 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 ...
4
votes
4answers
496 views
How to represent several points with same coordinates on map?
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 ...
0
votes
1answer
120 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 ...
6
votes
7answers
2k views
Extract raster values at points
How can I extract values from a raster by points. I prefer not in Arcgis. I prefer in Qgis or Mapwindow or other open source gis.
3
votes
1answer
227 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 ...
5
votes
3answers
237 views
Is there a tool to add “noise” to overlapping X, Y coordinates so they are no longer in the 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
284 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
389 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 ...
4
votes
1answer
2k 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 ...
2
votes
1answer
449 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
212 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 ...
0
votes
2answers
258 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 ...
5
votes
1answer
136 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
50 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
2answers
168 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
79 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 ...
1
vote
1answer
197 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
391 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
256 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
274 views
Setting up drawing order for point shapefile
I am having a difficulty with creating polyline feature from a point dataset that represents a boundary. This dataset consists of 5084 points which are randomly ordered. I have no Network Analyst ...
0
votes
2answers
673 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?
2
votes
1answer
198 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
267 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 ...
3
votes
2answers
2k 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 ...
4
votes
3answers
1k 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. ...
14
votes
2answers
2k views
How can I find a point inside a polygon in PostGIS?
How can I find a point that is guaranteed to be within a given polygon in PostGIS?
I am aware of the ST_Centroid function. However, the centroid is not always within a polygon, see below:
...
2
votes
0answers
342 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
4answers
595 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
4answers
1k 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 ...
3
votes
2answers
232 views
Housenumber(point) angle from line (street)
using arcgis 10 with Point data (Housenumber without angle attribute) and line data (street without angle attribute)
I want to create housenumber labels from point with correct angle from nearest ...
0
votes
0answers
79 views
Move or snap all annotation created from point layer
Et geo is a very good tool, I got angle from nearest line and i snapped all points to another line buffered with an exact position from the road ( 10 points 1:1500) some manual calculation was needed ...
1
vote
1answer
226 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 ...
9
votes
3answers
2k views
What is quickest way to select polygon by point in ArcGIS 10 using ArcPy?
I keep thinking that I must be missing something, but there does not seem to be a tool in ArcGIS 10 to select features (in particular polygons) from a layer at a point (X,Y) location via ArcPy. The ...
3
votes
2answers
598 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 ...
2
votes
2answers
248 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 ...
3
votes
2answers
639 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 ...
3
votes
1answer
255 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?
2
votes
0answers
51 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
4answers
2k 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 ...
0
votes
0answers
130 views
Plot data on a map [closed]
I've a data set contains three variables: longitude, latitude, population (in USA). I need to plot these data on a map. I use the following code (it works fine):
map("state", xlim = range(lon), ylim ...
7
votes
3answers
443 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 ...
2
votes
0answers
110 views
How does integrate work with point data sets?
I'm trying to combine point data into clusters and I think I've come up with a method that will work for what I want to accomplish. However, I don't understand why it works the way it does and I'm ...
11
votes
5answers
10k views
Get list of coordinates for points in a layer?
I've got a layer in QGIS that is comprised of points. Its attribute table doesn't have the corresponding x y coordinates for each point. Is there a way for me to extract a list of coordinates for ...
1
vote
1answer
64 views
Anyone know where I can find a file like this for Pakistan?
Can anyone tell me where I can find a file like this on Pakistan? I found it on ochaonline.un.org I cannot find it when I search on there.
...
3
votes
1answer
744 views
convert list of points to line or polygon
I have a list of Points in a PostGIS table. The rows can be grouped by a date
something like:
myTable
id INT
date DATE
lat NUMBER
lng NUMBER
geom GEOMETRY(POINT)
now I need a table where all ...
1
vote
1answer
223 views
PostGIS - table with 3d points with fast ordering by distance
I am pretty new to PostGIS and I am trying to solve the following problem.
I need a table with 3D points (x,y,z) that will contain around 1-10million points. I want to be able to efficiently ask the ...
