11
votes
0answers
256 views

How to query OSM for all beaches facing west? - QGIS preferred

I want to identify all beaches on this planet (or a given subset of it) that are facing westwards (+/- 20-30 degrees). My idea is to use OSM as the data source. Extracting all polygons that have the ...
10
votes
0answers
396 views

Scale in printed map (mxd) is different in code to manual printing

This question is related in part to a previous question I have asked. I have tried printing an A3 mxd with the Print Active View code as published by ESRI and have changed only one line of code and ...
9
votes
0answers
415 views

SEXTANTE toolbox - GRASS error

I am trying to use the SEXTANTE module GRASS (and SAGA) for vector analysis but whatever function I use I always get the same error:"Could not load layer: G:/closest.shp Check the SEXTANTE log to look ...
8
votes
0answers
304 views

File Geodatabase API .NET Wrapper - Determine if Table/Feature Class Is Locked

I have been using the file gdb api .NET wrapper, and it has suited my needs quite nicely (vs using ArcObjects). One of the things I have yet to figure out if there is a proper way to determine if a ...
8
votes
0answers
527 views

How to define Winkel Tripel in proj 4.8.0?

I have QGIS with proj 4.8.0 installed. I'd like to add Winkel Tripel projection which seems to be defined as +proj=wintri But that definition string does not work. Is this a bug in my proj version, ...
7
votes
0answers
659 views

GRASS v.Overlay/QGIS Intersect Speed intersecting line and polygon

Im currently trying to convert my scripts from ArcGIS to QGIS but one aspect that is extremely slow (imo) is trying to intersect a polygon with a line feature. I feel as though there must be a better ...
6
votes
0answers
73 views

What are the pros and cons of forcing square pixels on reprojection?

I am using Erdas Imagine 2014 to reproject 4-band raster data from GRS 1980 NAD83 Lambert Conformal Conic (ft) to UTM GRS 1980 NAD83 North UTM Zone 11 (m). Unlike ArcGIS, Erdas provides the option to ...
6
votes
0answers
48 views

Data Feed for Space Weather / Aurora

I am building a map application for a northerly area and would love to bring in a feed of northern lights prediction/probability (like below). http://www.gi.alaska.edu/AuroraForecast Does anyone ...
6
votes
0answers
390 views

Is there a good qml or sld file available for QGIS + Openstreetmap data?

I'm looking for a qml file (or equivalent e.g. sld) to allow me to use QGIS to take Openstreetmap data and produce paper maps. I'm re-asking this question (it was asked once or twice over a couple of ...
6
votes
0answers
162 views

How does Spatialite handle concurrent access?

I understand that Spatialite is meant to be used by a single user/machine at a time. However if the data is stored on server, there is no guarantee that someone on another machine will not also open ...
6
votes
0answers
436 views

Geoserver with SQL server consuming all my CPU

This question is long please bear me and my problem. SQL Server Query profiler The Sample Query from profiler that geoserver is running that corresponds to SLD I am using and not the SQL SERVER view I ...
5
votes
0answers
86 views

What PostGIS [topology] provided tools may be used for data quality assurance?

I'm learning about techniques to ensure GIS data quality. Googling around, I've found a few papers about theory and best practices (here and here), and a couple of short presentations about the topic ...
5
votes
0answers
103 views

fTools “Join Attributes by Location” missing in SEXTANTE/Processing Toolbox

I am working with the new Processing Framework in QGIS 2.0.1. I really like the graphical modeler, because it allows my to make my own tools without having to be able to write pyhton or any other ...
5
votes
0answers
80 views

Reprojecting elevation dataset for “tilted Earth”

I would like to create maps of a "tilted Earth", such as the following example where Australia is at the North Pole: http://i1048.photobucket.com/albums/s379/laskaris_mods/tilted_earth.jpg I can ...
5
votes
0answers
241 views

Histogram Matching Python

I am trying to do histogram matching using Python to improve the mosaicking process of multiple overlapping rasters. I am basing my code on that found at: ...
5
votes
0answers
136 views

Duplicate items in the legend

I have recently created a web map that uses the legend snippet from the ESRI JavaScript API website. https://developers.arcgis.com/en/jav...et_legend.html It works great for the most part, but has ...
5
votes
0answers
292 views

Create custom Authentication filter in GeoServer 2.3.0

Context In my current project, I've the requirement to validate that requests coming to GeoServer (2.3.0) are allowed. The project holds those facts: the GS client cannot provide the principal ...
5
votes
0answers
286 views

Modifying File GDB Feature Class Features Using QGIS

I've installed the File GDB API using the OSGEO4W advanced installation when installing QGIS. I've had a bit of trouble with it initially and have posted a few questions with some helpful Stack ...
5
votes
0answers
173 views

Why do file geodatabase and SDE readers produce different fme_geometry types?

I have one very simple workbench that I am running against both SDE (9.3) and FGDB (10.0) sources. I noticed two different fme_geometry values for same type of objects. For the first one, i.e SDE ...
5
votes
0answers
234 views

Plugin Workspace: when to close an OleDbDataReader?

I'm developing a plugin workspace for ArcGIS. Internally, the plugin uses an OleDBconnection. All of the sample code I see seems to stress the importance of closing and disposing the connection. ...
5
votes
0answers
74 views

Can I verify that attribute indexes are being used in a query from ArcObjects?

We have some software as part of a larger project written using ArcObjects via .NET. This software migrates and merges data from multiple file geodatabases in one schema to a single file geodatabase ...
5
votes
0answers
461 views

Evaluating map projection scale error

This is related to a previous question I posted. I am trying to quantitatively evaluate scale distortion associated with choosing different projection center, center azimuth, and scale factor values ...
5
votes
0answers
592 views

How to get rpy2 for QGIS on OSX?

I am a new QGIS user, have installed QGIS on a Mac running Snow Leopard OSX 10.6.8 following all the instructions. QGIS seems to work well for everything other than when I boot up I get the message ...
5
votes
0answers
695 views

How to create a routable road network from Ordnance Survey data?

I've been following the "Beginners Guide to pgRouting" in an attempt to create an in-house application that provides drive-time isochrones. I have a server, postgreSQL and PostGIS and pgRouting - no ...
4
votes
0answers
18 views

Is there a limit to the number of polygon points you can export to CSV in QGIS 2.4?

Using QGIS 2.4 I am currently importing a csv file with ~30,000 polygons (polygons in WKT format). I also have a United States shapefile. I have used the Clip function to get only the polygons that ...
4
votes
0answers
20 views

Does leaflet.js offer an gutter option just like Openlayers

Currently we are switching from Openlayers to leaflet.js and there is a problem using a WMS layer with leaflet. The WMS being used is Deegree. When a layer is visualised within leaflet there are ...
4
votes
0answers
79 views

Methods of cloud shadow detection for Landsat data?

Detecting clouds doesn't seem to be much of a problem, rather the challenge is in selecting cloud-shadow classes that don't also include coastal areas, agriculture, etc. For a project I'm working on, ...
4
votes
0answers
155 views

Bringing GIS data into Minecraft

A little off the beaten path...: Denmark has built a 1m:1block Minecraft World using real GIS data. Here's the home page, in Danish: http://gst.dk/emner/frie-data/minecraft/, and an ArsTechnica ...
4
votes
0answers
51 views

Compute visibility graph on sphere

I have a PostGIS table with some polygons (stored using the geography data type). They represent regions on a spherical earth. For each pair of vertices chosen from among all the polygons, I want to ...
4
votes
0answers
118 views

How to do Manhattan Voronoi on QGIS?

I've spending last two weeks trying to discover how to do a Manhattan Voronoi on QGIS. For the difference between Manhattan Voronoi and "normal" Euclidean Voronoi, please check this link Can someone ...
4
votes
0answers
36 views

Resources for Learning 508 Compliance/Accessibility Requirements for GIS Figures

Does anyone know of any quality resources (books, papers, presentations, websites) for learning about 508 Compliance/Accessibility requirements in relation to cartography (GIS figures and templates)? ...
4
votes
0answers
290 views

How to configure QGIS and SAGA on Ubuntu (12.04 and others)?

During the past weeks, I have tried QGIS to recognize SAGA via the processing toolbox, both being installed from the ubuntugis-unstable repository. I have tried this on several virtual ubuntu ...
4
votes
0answers
83 views

Help interpreting Moran's I and Geary's C results

I've got some doubts about how to interpret some results for a work. And I) would like someone could confirm or improve my conclussions. I made a correlation analysis with SEXTANTE software in gvSIG. ...
4
votes
0answers
80 views

How can I create a form so the user has to be authenticated to access a project?

I have a login form in QGIS and when it is loaded, python gives me an error for, apparently, not recognizing the findchild part. This is due to the fact that the form isn't loaded before the script is ...
4
votes
0answers
99 views

Convert Graphics to Vector in QGIS

I am wondering if there is a way to convert a graphic produced from symbology in QGIS to a vector layer (ie: shapefile). I have a point layer with bearing direction in the attribute table. Following ...
4
votes
0answers
52 views

Is there a way to constrain an FME.exe to certain amount of RAM?

If I have FME Desktop running on a workstation with a large amount of RAM (e.g. 128 GB), is there a way to constrain an FME.exe process to a certain amount of RAM (e.g. 48GB)? This question is ...
4
votes
0answers
53 views

EPSG code as dynamic text in ArcGIS

Is it possible to get ArcGIS to show the EPSG code for a coordinate system as dynamic text? The default text is quite verbose (see below), and I think just showing the "Coordinate System" is probably ...
4
votes
0answers
131 views

How to select features based upon multiple values in graphical modeler?

I'm trying to create a basic model using QGIS, the QGIS graphical modeler and the sextante toolbar. In part of the model, I need to select features based upon multiple attribute values (for example - ...
4
votes
0answers
182 views

Weather conditions forecasting / interpolation

I'm trying to carry out weather conditions interpolations. I have information of 92 weather stations for 800,000 km2. As you can imagine the extension of land is huge and I need some kind or weather ...
4
votes
0answers
245 views

QGis: Natural breaks (Jenks) - algorithm is buggy?

I don't know how the Natural Breaks (Jenks) algorithm works in QGis graduated symbolism, and I've deliberately not researched it in order to ask this question, as my point is based on what seems to be ...
4
votes
0answers
325 views

How to create a customizabe table in QGIS Print Composer?

I would like to add a custom table to a map layout created in QGIS. I would like a fair bit of control over the look of the table (borders, background colours of the cells, etc.), and it appears that ...
4
votes
0answers
337 views

Using stat_density2d with coord_map in ggplot2

In my example I am plotting a shapefile for all England & Wales, however I'm interested in the greater London area. If I allow ggplot to simply default and display the entire shapefile then the ...
4
votes
0answers
272 views

PyQGIS CRS on the fly reprojetion

As a first step of a pyqgis plugin I'm trying to import several shape files at once. To get them aligned, using the GUI, I'd enable on the fly reprojections and set the project crs to WGS84. I'd then ...
4
votes
0answers
156 views

How to build Poisson autoregression model

I have a SpatialPolygonsDataFrame object in R with about 3000 polygons and associated data. I have columns of expected and observed cases. For the moment, I don't have any covariates. I'd like to ...
4
votes
0answers
167 views

Cut polygon and retain data

I have these two polygons: library(sp); library(rgeos); library(maptools) coords1 <- matrix(c(-1.841960, -1.823464, -1.838623, -1.841960, 55.663696, 55.659178, 55.650841, ...
4
votes
0answers
847 views

How to open a ESRI geodatabase in QGIS (Ubuntu)?

So far I have found instructions on stack exchange but they are for windows. And so far the information I have found is for windows. I currently have Ubuntu 13.04 Raring tail. I am using qgis 1.8. I ...
4
votes
0answers
86 views

Estimation of values for unsampled points

I want to measure biomass on a coastal mudflat. I can only access points inside the polygon. Are there any methods available that would allow me to estimate values of the points outside of the ...
4
votes
0answers
502 views

Why is GDAL ECW compression much poorer than ECW compression from ERDAS

We use ECW compressor shipped with ERDAS Imagine to export Orthoimagery for our different departments. Because we are facing problems with the Imagine license server, we had to choose GDAL (built with ...
4
votes
0answers
199 views

How to create a topologically correct dataset in PostGIS (with GRASS)?

I have shapefiles which I have loaded in postgis and now i am trying to use geometric function in postgis like ST_intersect and they fail because the data is not topological correct. I have tried to ...
4
votes
0answers
195 views

GPS data based track/trip calculation algorithm available?

Currently I'm receiving position data of moving assets every 90 or 120 seconds (depending on the asset). What I'd like to achieve now is to detect standstill and movement phases (tracks/trips) on the ...

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