A geometric element defined by a pair of x,y coordinates.
2
votes
0answers
61 views
Point file to raster
I have a point file of trees in my study area, which includes the attributes of each tree. Each tree also has a crown radius associated with it. I need to summarize the attributes of these points ...
3
votes
0answers
77 views
Problems converting polygon to point
I'm trying to convert polygons to points with ArcGIS 10. My polygon layer has 2 attributes that I want to give to my point layer. I'm using the Feature to Point function from the Arctoolbox, but it ...
0
votes
0answers
34 views
Converting Points to Lines in ArcGIS AND retaining attributes of both start and end points
I have been searching and searching and I can't find a particular solution to what I need.
I have a table with animal location points. I need to calculate movement distances between points from the ...
3
votes
1answer
41 views
create grid cells of fixed dimension around a point acting as a centroid
I've been trying to solve a problem for the last few days but not having much luck. I'm hoping someone here can point me in the right direction. I'm new to ArcGIS so I hope my explanation makes ...
1
vote
1answer
64 views
PostGIS, create line from points
I have a PostGIS table with position data of numerous vehicles and want to create lines from these points. Data can be selected by vehicle id and ordered by timestamp but how to create lines from the ...
7
votes
2answers
620 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 ...
1
vote
2answers
46 views
How to select two points on a map using QGIS?
I need to select two points on a map in QGIS. I selected the element selection tool in menu view and I want to select two points. How can I accomplish this? Are there other tools or methods to ...
2
votes
1answer
80 views
Find projection of a point to a line
I have a segment defined by 2 LatLon points(A and B) and a third LatLon point (C).
I need an alghorithm, formulae, or some code to find the projection point of C on the segment AB (call this point D) ...
0
votes
2answers
37 views
add a vector point on OSM map
I have managed to show Lat and Lon
function init() {
navigator.geolocation.getCurrentPosition(function(position) {
document.getElementById('myloc').innerHTML="Latitude: " + ...
0
votes
1answer
81 views
Aggregate points with same values to polygons
I have a shapefile with 2M measurement points (each measurement point has a resolution of a 1/10). How can I aggregate points around each other if and create polygons out of it?
They do not have to ...
0
votes
1answer
25 views
Point to point distance over specified distance
I need to calculate the distance between neighbouring points which conform to a staggered line.
I have two point datasets, one being the baseline and another the monitor. The points typically reside ...
3
votes
1answer
47 views
How to delete points from CSV point layer?
I have a point layer produced from importing a Delimited Text Layer and I would like to delete some points. It seems that it is not possible to toggle editing in a point layer. How can I delete the ...
0
votes
2answers
52 views
Creating a 3D line feature based on 3D point features
In ArcGIS, is it possible to create a 3D line feature by drawing a line that connects 3D point features?
0
votes
1answer
63 views
Split polygons and extract points
I have a polygon file with 90 adjacent polygons. I also have a lat/long point file that overlaps the entire surface of the polygon file (170,000 points). My problem is that working with all of the ...
4
votes
4answers
127 views
How do I fill in serial letters (AA, AB,AC…,BA,BB,BC…ZZ) to a shape?
(I am using ArcGIS software, ArcMap...)
MY PROBLEM
I have a shape file containing points. The shape file contains 3 columns named FID, Shape* and Label. In the column I want to fill in AA, AB, ...
7
votes
2answers
712 views
PostGIS raster value of a lat/lon point
I have a tiff raster in my PostGIS 2.0 database. I want to get the value of the raster at a specified lat/lon point.
I have:
postgresql-9.1
postgis-2.0-svn with raster support
a raster imported ...
-1
votes
1answer
61 views
QGIS and Python - create line with multiple points in postgis
How can I create a line, with Python functions, with many points that are records in Postgis?
Thank you
1
vote
1answer
116 views
Is it possible to filter points that dont make sense compared to neighbour points?
I have a point shape (10.000 Points). Before interpolating theses points I need to filter them with a statistical background. Is there a tool or something I could use? Is it possible to select / ...
0
votes
0answers
29 views
Assuming nearest point for a region
I'm mapping agricultural cropping systems in Brazil using QGIS. From satellite images I got an raster file with 5136 x 5136 pixels from my field work.
Now I need to associate many soil/climate ...
2
votes
1answer
119 views
Postgis 1.4 - Obtain closest point of point over polylines layer (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 ...
1
vote
1answer
50 views
random sampling from spatial points in R
Can anyone help me out on the best package to sample from a spatial point dataset?
My dataset consists of a list of positions inside a region, and for each point I also have the name/number of the ...
1
vote
1answer
28 views
generate random world point geometries
I have a world map. I need random point geometry. So, how can I randomly generate point coordinates? Any programming language. Also, I am using SRID 4326.
Any programming language.
0
votes
2answers
52 views
Joining Points and Polygons
I am new at using arcGIS 9.3.1 and am having trouble joining data. I have a shapefile of census tract polygons and a separate file of points that are crimes in Chicago in 2010. The crime points were ...
4
votes
2answers
108 views
How to join number of point features into attribute of nearest line segment
I have point shapefile with lot of attributes, that represent road accidents and line shapefile with highways. What i want is to join attribute into line shapefile with value, that represent number of ...
4
votes
1answer
107 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 ...
1
vote
2answers
40 views
simplify point geometry
I have a great amount of points and I need to show them on map. I am using OpenLayers. Is it possible to simplify point geometry in order to speed up the process of rendering?
5
votes
1answer
138 views
NYC Subway Line Station Order?
I've currently got data on the NYC subway stations (including name, position, and how many people entered and existed during a timeframe). Also, I have the data on which stations have which train ...
0
votes
0answers
32 views
How to add vertices to existing linestrings in mysql?
Is it possible to add a Point at the end of a Linestring in MySql?
For example I have a Linestring as
Linestring(1 2, 1 4, 1 6)
and I want to add a Point
Point(1 7)
at the end (output should ...
1
vote
0answers
60 views
How can I move two layers at once in QGIS?
I'm trying to move two digitized layers, one containing points, the other polygons to a different location at the same time. QGIS doens't seem to allow this. Even if I select both layers and features ...
1
vote
0answers
86 views
How to calculate average value within a polygon(in Qgis with Python)?
Now I have a point and polygon shapefile
and I want to calculate the points' average value within each polygons
How to do it with python?
I tried to find out but google gives me a lot of raster ...
3
votes
1answer
57 views
Convert polygons to a number of randomly located points based on polygon size
ArcMap 10.1 on a PC. Working with a large shapefile with ~50,000 poygons with a wide range of size from 1,000+m. to <1m. I would like to convert these polygons into points so I can do some analysis ...
1
vote
0answers
42 views
Join .csv file and .shp of georeferenced points
I have georeferenced a map and saved a selection of some points on the map. These points are cities of departure and arrival and I want to join the .shp with a and excel .csv with the information of ...
2
votes
2answers
66 views
How can I disperse points within polygons using ArcGIS?
I have huge number of points. These points are within polygons. I want to disperse the points in the polygons randomly. I tried to use the disperse point extension in Arcview, but it was not useful ...
4
votes
3answers
3k views
OpenLayers: Showing a WFS overlay on top of Google Maps
I have found similar questions asked previously, but I still fail to get a simple WFS point layer to work using OpenLayers and Google Maps. The original code I used was based on WFS polygon layers I ...
4
votes
3answers
2k views
How do I convert a polygon into a point?
I want to convert polygons into points. I know how it's done in ArcGis and I think this may sound trivial but it's a serious issue :/.
I'll appreciate any hints :)
0
votes
1answer
28 views
How to obtain and compare neighboring point attributes? (ArcInfo)
This question is kind of hard to explain in a short phrase, so this is what I'm talking about. I have access to an ArcInfo 10 license.
I have a layer of point features that all have a "Team" ...
6
votes
4answers
227 views
How to calculate the “depth” of a linestring using postgis
I have linestring features, which look like bent linestrings, hemicycles or convex or concave linestrings. In the moment I can select the distance between the startpoint and endpoint of each feature. ...
0
votes
0answers
75 views
How to insert vertex in polyline layer where we have a point in a point layer
I have a polyline layer and a point layer. Some of the points are on the polylines, but the polylines do not have vertex in these points.
How can i insert vertex there ?
0
votes
2answers
62 views
Manually add a new point to PostGIS table [duplicate]
I did accidently delete a table row - or well, in fact a whole subway station.
My attempt to solve the problem was this PostGIS function:
ST_GeomFromText('POINT(coordinates)')
But then PostgreSQL ...
2
votes
1answer
80 views
How does Flow Mapper Plugin work?
I downloaded the Flowmapper plugin for Qgis and I can't seem to find any information on how it is supposed to work...
Also the text seems to cut-off and not fully showing for the input fields so I'm ...
2
votes
1answer
102 views
Correct coordinate systems, but trustworthy distance between points?
I have limited GIS experience with projections and I have some questions about trying to accurately display point data from two different sources in ArcGIS 10.1 in order to do a proximity analysis.
...
8
votes
1answer
113 views
Measuring distances between simultaneous points
I am working with GPS data and so I have UTM's with DATE/Time information. I have 2 groups of species (moose and wolves). I want to join the information from moose to wolves that match in time. So, ...
5
votes
3answers
120 views
GIS file format for space and time data?
I need some advice with GIS file format choice.
Here is my problem:
I have about 100 stations.
At each station water temperature is measured daily for 1 year
I want to load this data to QGIS and be ...
1
vote
2answers
67 views
Layers with same coordinates not lining up [QGIS]
I have a project where I have a few layers (State of Texas, cities, roads, etc.). They are all resaved and projected to NAD83 / UTM zone 14N EPSG: 26914. The project CRS is also NAD83 / UTM zone 14N ...
0
votes
2answers
109 views
Road network Analysis
I have a Road layer and Point features of some Bus stops from the same area.I want find the Road distance between the Bus stop.Please help me find it.
I have QGIS,ArcGIS,and FME.
Thanks,
RKM
0
votes
1answer
214 views
Make POINT from longitude/latitude coordinates from existing table in PostGIS
I would like to make a POINT using the longitude and latitude columns of an existing table. Here's a link to the documentation of ST_MakePoint.
Here's my table:
CREATE TABLE sysinst.bio (
oid ...
0
votes
0answers
53 views
Splitting a TAB file by attribute?
I have TAB file with LOADS of points. Each point as a unique ID and group assigned to it (ranging from 1-154). I'm wondering if there is an easy way to split this up into a TAB file for each group, ...
7
votes
8answers
10k views
In arcgis 10 how can I turn a csv file into a point shape file using lat/long data within the csv?
Greetings everyone! I have a csv file that is 133mb in size and has over 1.3 million lines of data. Each line of data has its own lat/long and I was wondering what would be the best way to display ...
1
vote
2answers
164 views
How to calculate the angle between two points (according to a reference point)
I need to calculate the angles between two points on ArcGIS. I have ArcInfo License, too. I have 5 points on a diagram. One of them is my reference point. The other four creates angles between each ...
2
votes
2answers
123 views
Calculating the distance between points and multiple lines
I have a point shapefile of about 100 points and a polyline shapefile of about 200 lines and I am interested in finding the distance between every point and each individual polyline. My polyline ...
