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1500 questions
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2 answers

How to best model GPS tracks for storage, visualization and analysis?

I am thinking about writing software to deal with GPS Tracks and Waypoints (mostly storing, displaying and calculating metrics such as speed, grade, and some simple statistics). I wonder what should be the most conceptually robust data model…
heltonbiker
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6 answers

how to overlay a polygon over SpatialPointsDataFrame and preserving the SPDF data?

I have a SpatialPointsDataFrame with some additional data. I would like to extract those points inside a polygon and at the same time, preserve SPDF object and its corresponding data. So far I've had little luck and resorted to matching and merging…
Roman Luštrik
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18
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2 answers

Convert a spatial polygon object to data frame using R

My goal is to modify an existing shapefile by merging certain polygons. After importing the shapefile and using the UnionSpatialPolygons command, I get the polygon outline that I want. However, this is now a SpatialPolygons object and not a…
John
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18
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3 answers

Differences Between Clip Tool and Intersect Tool

How is the clip tool different from the intersect tool in terms of how it works or the result? I don't have a specific situation in mind. I was learning about each of these tools and was curious about how they differ since the results seem to be…
Diana Di Leonardo
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18
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5 answers

Calculating Topographic Ruggedness Index in ArcGIS Desktop?

Does anyone know how to calculate Topographic Ruggedness Index (a.k.a Terrain R.I.) in ArcGIS Desktop without access to command line ArcInfo Workstation? "The topographic ruggedness index (TRI) is a measurement developed by Riley, et al. (1999) to…
matt wilkie
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18
votes
6 answers

Copy, not export, a table from Arcmap

How can I copy a table, or selection of rows or columns in a table, from Arcmap without going through the pointy-clicky-typey exercise of Export table? The destination of said copy could be anything: notepad, excel, word, whatever. The existing…
matt wilkie
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18
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4 answers

Filter features based on their attributes using Python

How to get features by their attributes (similar to 'IQueryFilter' in ArcObjects) in QGIS using Python? Instead of getting all features and filter it manually, is there any option to use where clause to filter it out? Example: I have a field name…
venkat
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18
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1 answer

OpenLayers Plugin Error: latitude or longitude exceeded limits

I'm aware the 'traceback' OpenLayers plugin error has been dealt with before. Unfortunately for me, the solutions posted were way over my head, e.g. using workarounds and code posted on github, etc. I find it all mind-boggling. The error message…
Almac
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18
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1 answer

Calculate area within Python script in ArcMap

I am trying to calculate the area of a polygon within my Python script. I create a new polygon from merging two together, and I'd like to add the area of the resulting polygon to a field in the output file. The polygon is stored in a regular…
Martin
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18
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2 answers

Counting and rasterizing polygon overlaps in ArcGIS Desktop?

How do you take a vector layer with overlapping polygons and turn it into a raster where each cell counts the number of polygons containing that cell? We are looking at polygons of fire burn areas between 1976 to 2000 and want to see how many…
user15201
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18
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2 answers

Which is correct projection in ArcGIS Server for EPSG:3857/900913?

I want to publish a mapservice in ArcGIS server, which will be overlayed on Google Maps or Bing Maps. For this, the Map Service needs to be in EPSG:3857/900913. The Google Maps projection is supposed to assume a Spherical Earth Projection. So I went…
Devdatta Tengshe
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18
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0 answers

Creating trade flow maps in ArcGIS for Desktop (or any free software)?

I am trying to represent trade flows on a world map where the size and direction of arrows indicate the exports/imports of a given country. This type of map is commonly found in magazines and newspapers. However, I find it extremely difficult to…
relima
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18
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6 answers

What are key things to test in ArcMap 10.1, service pack 1?

I have been asked to test service pack 1 for ArcMap 10.1 before it is provided to other users at my university. Are there any key things I should do for any SP test, or should I try to look at things that have specifically been addressed in this…
Flo Harrison
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18
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3 answers

What is the wire format for Google's new vector map tiles?

Google recently released new vector cartography for their mobile maps. I'm curious if anyone here has any insight into the wire format they use for transmission? I've experimented with a few formats over the years, including bencode, bson, variants…
Michal Migurski
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18
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4 answers

Where can I download the Google Road network as shapefile?

Is there any site from where I can get Google Road network as shapefile? As per my knowledge It is not distributed by google. So anybody can suggest how can I create this road network for a custom use?
Devils Dream
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