36
votes
7answers
3k views

Best practices for PostGIS production environments?

What PostGIS documentation have you come across that has been helpful when tuning PostGIS for a production environment? I would like to get together with my DBA to setup a Postgresql/PostGIS ...
35
votes
7answers
5k views

How can I effectively debug arcpy Python scripts?

I have written many Python scripts using arcpy in ArcGIS 10, and so far my only means of debugging is restricted to printing messages to the geoprocessing results window using arcpy.AddMessage(). Are ...
29
votes
5answers
7k views

Comparison of the different open source GIS servers

I currently know the following open source GIS servers: Geoserver: java based, vector and bitmap support, also supports. Is now on par with mapserver (performance-wise). mapserver: c/c++, used to be ...
20
votes
2answers
3k views

Spatial ETL comparisons

I am hoping some of you experts out there can list the pro's and con's of various spatial ETL (extract, transform, load) tools. If you have used these items listed here (or add your own), please ...
20
votes
3answers
5k views

Simple thematic mapping of shapefile using Python?

I wish to visualize geographical data in Python, without using ArcGIS/ArcPy, and make a map. On the internet I found how to make a thematic map using Python: Here is some code that I tried: ...
22
votes
8answers
5k views

GIS jobs online

What are the best websites for scouting GIS related jobs?
37
votes
7answers
8k views

What are Esri's new “ArcGIS for Professionals” and “ArcGIS Pro”?

After looking through all the stuff that was released or talked about at the Esri UC I am still genuinely confused by what ArcGIS for Professionals is. I will admit that it looks pretty cool, and has ...
26
votes
4answers
2k views

How to use directional shading on boundaries for cartographic effect?

The attached screenshot of a National Geographic map shows some beautiful directional shading of boundaries. I'm trying to reproduce this sort of shading for a burn perimeter map, as I want to ...
22
votes
2answers
2k views

How to represent trend over time?

I have a time series of rasters where the cells of each raster represents some value at a certain time. I'd like to generate a map that highlights the magnitude of positive or negative trends in this ...
18
votes
9answers
9k views

Bulk Geocode 20 million records

Are there any free or reasonably priced databases for the US which can be searched and return latitude and longitude information?
18
votes
4answers
2k views

How do GIS web apps work?

I am completely new to GIS and therefore have questions regarding how the GIS Web development should be made, because the entire concept still confuses me. So, imagine I have a map. And by this, i ...
20
votes
1answer
7k views

How to change the SRID of exisisting data in PostGIS?

While importing my shapefile data to PostGIS, I did not select the proper Projection. How do I now change the SRID of the data, without transforming the Coordinates?
19
votes
1answer
5k views

Trilateration algorithm for n amount of points

I need to find algorithm that can calculate centroid A (aka gravity center, geometric center, center of mass) from the figure where circles T1,T2,T3,T4,T5,..,Tn intersect AND length of line R from ...
13
votes
9answers
15k views

How to convert KML to shapefile without losing attributes?

I'm new to QGIS and all geoinformation itself but have to work on some difficult stuff. I have a KML file with hundreds of points. To each point there is information, such as Name, Power, Age (it's a ...
20
votes
5answers
3k views

How to create regular point grid inside a polygon in Postgis?

How to create, inside a polygon, a regular grid of point spaced x,y in postgis? Like the example:
10
votes
3answers
3k views

Land Cover Feature Extraction from Satellite Imagery

I'm interested in a low-cost or open source solution for creating land cover GIS layers that utilize both spectral and textural extraction algorithms. I have used PCI Geomatica, ENVI, and Feature ...
9
votes
4answers
2k views

Connecting line features and determining the length of the longest line

I have a line feature (see image) representing a river that I created using the Stream_to_Feature tool. The attribute table contains several records representing different lines - the problem is the ...
8
votes
1answer
1k views

Creating table containing all filenames (and possibly metadata) in File Geodatabase?

I need to create a metadata-table for all files in a File Geodatabase or Spatial Database. It would be awesome if it were possible to automatically be updated with new filenames, and possibly even ...
21
votes
7answers
17k views

Removing small spaces (slivers) between polygons?

I have a set of polygons representing administrative districts. The districts were digitized by hand, and there are small spaces (slivers) between polygons where the polygons should be touching. How ...
20
votes
3answers
2k views

Packing Polygons within polygon

I have a Boolean raster. In the grey areas of the raster I would like to fit a given size polygon within a contiguous extent. Basically, I have an irregular polygon, and i would like to "fit" a ...
8
votes
6answers
3k views

Get a point on a polyline from end points given distance along poly line

I have start point and end point of a polyline. How can I get a point on that polyline from end points specified by the given distance. How can I get this by using arcpy provided that this script ...
19
votes
2answers
7k views

How to convert .shp into .gpx using QGIS?

I'm newbie using QGIS. I would like to convert .shp into .gpx. So, using Qgis, I open my shapefile and I tried to "save as" gpx but it gives an OGR error: creation of field ObjectId failed (OGR ...
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 ...
15
votes
2answers
4k views

How can I convert data in the form of lat, lon, value into a raster file using R?

I have a data set of values over a km grid in the continental U.S. The columns are "latitude", "longitude", and "observation", e.g.: "lat" "lon" "yield" 25.567 -120.347 3.6 25.832 ...
8
votes
3answers
539 views

How to apply the four colors theorem in a polygon map in ArcGIS/ArcToolBox automatcally?

I need to apply the four colors theorem in a polygonal shape in a way that I do not need to choose manually each color to put in each region. I wish to knows if there is any extension, plug-in, script ...
8
votes
2answers
2k views

Cartographic techniques for symbolizing routing data

Some common problems with displaying routes created from street data, such as bus routes, include: Routes may overlap themselves, such as when a route takes the same road in opposite directions ...
7
votes
1answer
1k views

Sort layers in QGIS table of contents?

When I load a bunch of layers into QGIS from PostGIS, they seem to load in reverse alphabetical order. Is there any tools or plugins that allow you to quickly sort the QGIS TOC in a different order? ...
7
votes
2answers
2k views

How to re-order fields permanently using ArcGIS Make Query Table tool?

In the Answer to somebody else's question it was stated that the Make Query Table tool could be used to re-order fields in tables and feature classes permanently. However, when I open the dialog for ...
7
votes
7answers
4k 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.
6
votes
1answer
2k views

How to force ArcGIS to recognize a text field in a CSV file?

Related to Data-type detection in ArcGIS table loading I have a CSV file which contains a mixture of numeric and text fields: ID,Txt,Int,Dbl 12345,abc,45,56.78 12346,9,65,23.12 12347,10,66,23.13 ...
12
votes
5answers
8k views

How do I create a convex hull in ArcGIS Desktop?

I would like to be able to create a convex hull in ArcGIS Desktop 9.x, but I cannot find an appropriate tool. How does one go about creating one? I am interested in answers for all license levels: ...
6
votes
1answer
4k views

How to create a point along a line given distance

I have been given a non-spatial database which contains the names of lines which I have a shapefile for. The database also has names of points and the distance of each point from the origin along the ...
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
709 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
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 ...
13
votes
2answers
3k views

Using Geodesic Measurements for Circle Radii?

I am currently developing an OpenLayers mapping site. Measurements can be made using a line tool, and an area tool. Both of these are currently set to calculate geodesic measurements as outlined in ...
7
votes
1answer
570 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
2answers
638 views

Iterate through multiple Raster files and compute statistics using Zonal Statistics

I have a large number of raster images. What I'd like to do is to compute statistics on different sections of these raster files using a polygon. I think everyone is suggesting Zonal statistics. ...
31
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 ...
39
votes
8answers
10k views

Creating drive time polygons using open source tools

Is anyone using open source tools and/or data to generate drive time polygons that radiate out from a given location? For example, I have used ESRI products like Network Analyst and Business Analyst ...
26
votes
3answers
7k 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 ...
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 ...
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 ...
18
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
9answers
2k views

Discontinuous or Interrupted map projections?

Do any of the current open source GIS softwares support discontinous projection systems? E.g. sinusoidal, dymaxion, butterfly, etc? If not, are there any affordable commercial ones that do (affordable ...
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 ...
25
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 ...

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