8
votes
3answers
957 views

When do I need to use a proxy with OpenLayers?

When exactly do I need to use a proxy with openlayers? I've done a lot of reading on this but can't seem to find a difinitive answer. Wondering if this is the route of my problems. For instance, if I ...
5
votes
2answers
2k views

How to add links to PDFs in a Shapefile?

I have a problem. I want an attribute in a shape file named "Link" to add. The works are all fine. But then I would like to add a link in my directory. This link accesses a PDF. Now, this PDF is not ...
5
votes
1answer
743 views

Qgis polygonize problem - DLL load fail

I have a raster file and I want to perform the method "polygonize". Then the problem occurs, that is shown on the screenshot. It doesn t have anything to do with the rasterfile format, I veryfied. ...
3
votes
4answers
2k views

Cannot fix QGIS after upgrade to Ubuntu 13.04 Raring

I have following problem. After upgrade to 13.04 I had problem with PyQGIS mentioned here. I followed almost all advices described there, finally removed QGIS (had 1.8 Lisboa) and added the Ubuntugis ...
3
votes
1answer
2k views

How do I find vector line bearing in QGIS or GRASS?

How can one extract the bearings from a set of lines in a vector file? I'm trying to find the bearings of several straight vector line segments (simplified contour lines, actually) and can't figure ...
3
votes
2answers
1k views

ArcObjects + comtypes at 10.1

Has anyone played around with using ArcObjects in Python at version 10.1? I am having all sorts of problems, such as TypeErrors when wrapping the ESRI OLB modules and AttributeErrors when attempting ...
7
votes
1answer
599 views

How to reopen hidden panels in print composer?

I unfortunately deleted the menu (Qgis 1.8.0) in print composer (settings for labels etc) . Now I am wondering how to display it again? The menu is gone in all my projects and I could not find a ...
4
votes
2answers
2k views

Unable to create WFS successfully

I know there has been lots of WFS assistant and I did follow this one word by word, which I found was the best in the entire gis stack but still no clue why I am unbale to render a WFS on base map. ...
2
votes
3answers
251 views

How to determine bare earth from unclassified LAS file

I have data in LAS format with RGB values created from Aerial photogrammetry using a UAV. I am trying to find a solution to extract the bare earth to create my DTM from the DSM. I have tried SAGA, ...
45
votes
13answers
11k views

Resources for learning Python programming with generic GIS goals in mind?

In your opinion, what is the best book/site to learn Python with GIS goals in mind? By "best", I mean: not very long (book) easy to understand (book/site) good practical examples (book/site) For ...
33
votes
2answers
4k views

Acquiring ArcGIS-like speed in Postgis

I have been using Postgis 2.0 for 3/4 of a year now and while I really enjoy using it, excessive query processing time has rendered it basically unusable for my use case. I tend to do heavy ...
31
votes
9answers
11k views

Open source methods for kriging?

I have a point dataset which I'd like to Krige, ideally using an open-source software package. If possible, I'd also like to choose the semi-variogram model during the process to improve the ...
27
votes
3answers
9k views

Alternatives to ArcGIS Online?

I am considering purchasing ArcGIS Online for a group of users who currently use about 5% of ArcGIS capabilities (ArcMap, simple map creation and information display) about 80% of the time. Primary ...
33
votes
6answers
9k views

Downloading OpenStreetMap Data

Is there a straightforward way to download data from OpenStreetMap (OSM)? Using North America as an example, I realize Cloudmade (http://downloads.cloudmade.com/north_america) and geofabrik ...
22
votes
3answers
1k views

Best practices for organization and tidiness - How do you deal with multiple copies of layers?

Back in the days when I was in the university I had a "Organization and tidiness" problem – I was unorganized and kept my layers in different folders without distinct names and hence had multiple ...
24
votes
9answers
2k views

Effectively displaying demographic data on a printed map

I would like to plot the following per zone (30 zones total) data on a printable/non interactive map: Average age Average household income Number of households Population density Number of people ...
19
votes
6answers
7k views

Ways to Speed Up Python Scripts Running As ArcGIS Tools

This is a pretty general question. I just wondering what tips and tricks GIS programmers have used to speed up arcpy scripts that you import into the toolbox and run. I work most everyday writing ...
25
votes
9answers
13k views

How to connect to PostGIS database from ArcMap?

How can I connect to a PostGIS database from ArcMap? Solutions for ArcGIS 9.3, 10.0 and later are acceptable. Ideally, I would like to be able to perform spatially enabled queries and receive the ...
21
votes
5answers
13k views

Is ArcSDE no longer needed at ArcGIS 10.1?

Through my frustration of not finding the post-installation wizard with ArcSDE 10.1 and being unsuccessful with the command line tool to start an SDE service on our SDE databases, I found I was able ...
19
votes
7answers
6k views

Nearest neighbor between a point layer and a line layer

I've asked this question several times on stackoverflow and irc between #qgis and #postgis and I also tried to code it or implement it my self in postgis with no real answer. Using programming (most ...
19
votes
3answers
4k views

How can I switch line direction in QGIS?

Something that is hopefully pretty easy. I would like to be able to swap the direction of a polyline/line in QGIS. I made a custom tool to do this in MapInfo a couple of years ago, however I can't ...
15
votes
2answers
2k views

Calculate distortion outside a UTM zone

One of my colleagues is working with data that is spread across two UTM zone. The majority of the data is in one zone, with a few outliers in another zone. He would like to know what the area ...
14
votes
4answers
17k views

How do you decide what interpolation method to use for resampling raster data?

The question pretty much says it all; are there hard and fast rules about which interpolation methods are suited to each kind of raster data? Any Golden rules, rules of thumb? Good books or articles ...
26
votes
3answers
8k views

How to make a spatial view in PostGIS and add it as a layer in QGIS?

In PostGIS 2.0, what is the most efficient way to create a spatially enabled view that is viewable in QGIS? I followed the context of Part 2 of @Mike Toews answer to this question, and the view ...
18
votes
1answer
4k views

Calculating Flow Direction and Delineating Basins from Projected vs. Unprojected DEM Data

This is somewhat of a theoretical question stemming from some discussions with colleagues on the topic of implications with delineating basins with projected (e.g., Albers Equal Area) vs. unprojected ...
14
votes
4answers
9k views

Creating Centrelines from Road Polygons/Casings?

I want to create center lines from road polygons. Are there any automated tools in ArcGIS for Desktop to do this? I am including a Screenshot of my vector file below.
12
votes
6answers
4k views

ArcObjects Resources

What are the best books/web sites for C# development with ArcObjects? The ArcGIS Resource Center is very helpful, but I am trying to find sources with more examples. Thanks
10
votes
4answers
3k views

Code to calculate elevation profile along line from a DEM

Given a DEM (Digital Elevation Model) say in and a line (x1,y1) --> (x2,y2) (paired coordinates (x,y)), how can one calculate the elevation profile or cross-section projected on that line ? I am ...
20
votes
10answers
19k views

Best way to add Attribute data to a shape file

Hei GISers!! Thanks for your help with my previous question. My apology if this may be too simple a question for this site, but I am still learning the various aspects of GIS. Now that I can ...
8
votes
1answer
307 views

Using customized Coordinate System for Archaeological site data

I don't know so much about coordinate systems... In my office we use to deal with spatial data coming from archaeological sites. Each site has its own x-y-z coordinate system (GCS). Three simple ...
8
votes
11answers
2k views

Device for Logging GPS and Accelerometer Data?

I am looking for a device that can track my location (lat,long) and speed all day long. Perhaps, I need GPS and accelerometer data bundled together. What I want to do is to log my daily activities. I ...
7
votes
1answer
3k views

Is there an comparison of the various mapping libraries for Android?

I am currently looking at the various libraries that I can use to show a map in my custom Android App. I have found several like Mapsforge, OSMDroid, ArcGIS runtime for Android, Google Maps for ...
7
votes
4answers
4k views

How to split a vector in equal smaller parts in QGIS or similar?

i want to divide a shapefile with many tiles into a lot of smaller tiles. I am searching for a smart solution, because manual edits are out of questions Anyone can help or know a nice function?
18
votes
3answers
2k views

How to calculate the intersection of 2 Circles?

I'm trying to figure out how to mathematically derive the common points of two intersecting circles on earth's surface given a center Lat/Lon and a radius for each point. Ex. Given: Lat/Lon ...
18
votes
4answers
8k views

Joining non-spatial CSV file to spatial data (shapefile) using QGIS?

I have a CSV file which has postcode data in a field, but it is non-spatial e.g. no Easting and Northing. I have a shapefile with postcode in a field and some additional data. I want to join the ...
15
votes
3answers
2k views

How do I find the distance between two coordinates in an ellipsoid?

Lets say I have two sets of latitude and longitude. How do I find the distance between the two locations if I assume the earth is a perfect ellipsoid (with an eccentricity of 0.0167)?
10
votes
2answers
1k views

How can I convert geomagnetic coordinates to geographic coordinates without doing the math myself?

I have some data which are in geomagnetic coordinates; that is, they are latitude and longitude, but in reference to the magnetic north pole in Canada rather than the geographic north pole. As you ...
6
votes
3answers
5k views

How to convert Distance, Azimuth, Dip to XYZ?

I have an excel spreadsheet with header and survey drill data. Header data contains hole ID, and location coordinates, and the survey data contains related downhole survey with Distance, Azimuth and ...
14
votes
1answer
2k views

Voronoi polygons that run out to infinity

I have been working on implementing the voronoi.py script (Bill Simon's translation of Steve Fortune's code). According to the QGIS link it is basically the same code that I am working with, but the ...
11
votes
2answers
2k views

Which function for creating a POINT in PostGIS?

When defining a Point in PostGIS, when do you decide to use which of the following? ST_SetSRID(ST_MakePoint(lon,lat),4326) ST_SetSRID(ST_Point(long,lat),4326) ST_SetSRID(ST_GeomFromText('POINT(lon ...
10
votes
1answer
1k views

Is there a way to access QGIS plugins in Python?

Is there a way to access QGIS plugins in Python? I'd like to write a script to do some geoprocessing, and I'd like to use the clip, regular points and convex hull tools in fTools, as well as the Road ...
8
votes
2answers
2k views

Workflow for determining stream gradient?

As far as data goes, I'm working with NHD .shp files, 10m DEMs, and some LIDAR data. My goal is to determine gradient for 100m segments of a network of streams. I'm already able to do this, but I ...
8
votes
3answers
2k views

Ordnance Survey grids - download or generate?

Does anyone know a source from which to download vector UK Ordnance Survey grids at varying resolutions? Or failing that, a tool that can create an OS grid at a specified resolution? There are plenty ...
6
votes
1answer
1k views

Nearest Neighbor calculation in PostGIS

I'm learning how to use PostGIS and spatial databases for analysis. What I am trying to do is perform a calculation to get the distance for the nearest polygon in a file, using the edge calculation, ...
5
votes
3answers
3k views

Is it possible to have a dynamic table in a data driven page environment?

I am creating a map series that has many polygons per sheet. There is annotation for the polygons however some polygons are very small with no annotation for them (annotation would completely hide a ...
5
votes
2answers
5k views

Rotating a vector layer in QGIS with qgsAffine (or other method)?

I would like to rotate a set of vector points in QGIS an arbitrary number of degrees around a central point (or arbitrary point). This is similar to a recent question about creating a regular grid; ...
5
votes
3answers
7k views

How to convert coverage (.adf) to shapefile?

Is there any tool or software except ArcGIS which I can use for converting coverage (.adf) files to shapefiles?
9
votes
3answers
3k views

How to programatically check for a mouse click in QGIS

I want to know how to check for a mouse click in QGIS. I am trying to write a python plugin and want to provide functionality similar to the "Select Single Feature" tool that already exists in QGIS. ...
7
votes
3answers
4k views

Tutorials for geoserver

Do you know any sources from where i can learn how to use geoserver? I know this two sites: http://geoserver.org/ - which in fact is not working (at list at the moment) ...
6
votes
3answers
3k views

How to read Greek fonts (ISO-8859-7) in shapefile attributes within QGIS 1.8.0?

I'd like to ask whether there is a way to read greek fonts in a shapefile's attribute table within QGIS 1.8.0.

15 30 50 per page