Publications by dylan
Importing Weather Data from Wunderground
Wunderground Example The Wunderground.com website offers several creative interfaces to current and historic weather information. One of the more interesting features is the URL-based interface to personal weather stations. As far as I can tell, the Wunderground website only returns hourly data for a single day from personal weather stations… I...
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First-Cut Approach to Synchronizing Field Notes with GPS Data
After a week’s worth of work in the field, I typically have several pages of hand-written field notes that are associated with GPS waypoints– badly in need of some kind of transcription/organization. I have yet to find a simple approach for bringing together these non-spatial (field note transcriptions) and spatial (waypoints) data, linked on...
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Terrain Classification Experiment 2: GRASS, R, and the raster package
Quick post on terrain classification, based on some trouble folks were having with a previous example on Windows. With the spgrass6 package, raster stacks are created by loading several GRASS files at once: x <- readRAST6(vname=c('beam_sum_mj','ned10m_ccurv','ned10m_pcurv','ned10m_slope')). This works well on UNIX-like operating systems and in ca...
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Saving Chunks of SSURGO Data in SoilWeb for Google Earth
SoilWeb is an interactive, multifaceted interface to USDA-NCSS soil survey information. Our SoilWeb application for Google Earth streams soil map units and point data as you navigate across the lower ’48 states. Currently, our system imposes a 30,000 ac. limit (defined by the Google Earth viewport) for streaming detailed soil survey (SSURGO) ma...
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Recent Updates in the aqp (Algorithms for Quantitative Pedology) Package for R
New version of our ‘aqp’ package for quantitative soils investigations, available on CRAN (version 0.99-5) and R-Forge (0.99-8). Some of the major changes are listed below: -------------------------- aqp 0.99-8 (2011-09-14) -------------------------- * soil.slot() will now accept boundaries defining a 'slab' over which aggregates are computed...
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Soil Series Query for SoilWeb
A map depicting the spatial distribution of a given soil series can be very useful when working on a new soil survey, updating an old one, or searching for specific soil characteristics. We have recently added a soil series query facility to SoilWeb, where results are returned in the form of a KML file. Two modes are currently supported: map un...
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Soil-Landscape Block Diagrams in SoilWeb
Users of our Google Earth interface to USDA-NCSS soils information will now see links to soil-landscape block diagrams listed within map unit descriptions. Automated Linking to NCSS Block Diagrams read more Related To leave a comment for the author, please follow the link and comment on their blog: dylan's blog. R-bloggers.com offers daily e...
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PostGIS Quickie
Today I needed to cut out a rectangle of geologic data from a state-wide map in an AEA coordinate system, using a bounding box from a UTM zone 10 region, with the output saved in UTM zone 10 coordinates. PostGIS makes this type of operation very simple via spatial SQL. Note the special syntax that PostgreSQL uses for referencing variables. Spati...
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Logistic Power Peak (LPP) Simulated Soil Profiles
A friend of mine recently published a very interesting article on the pedologic interpretation of asymetric peak functions fit to soil profile data (Myers et al., 2011). I won’t bother summarizing or paraphrasing the article here, as the original article is very accessible, rather I thought I would share some new functionality in AQP that was i...
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AQP 0.9-9 is ready: 1.0 should be out by 2012-01-01 !
Version 1.0 of AQP is nearly ready– after nearly 3 years of development, 2 years on R-Forge, and 1+ year on CRAN. Just pushed version 0.9-9 to R-Forge, and it should be on CRAN within a couple days. Recent changes are listed below, clipped from the NEWS file. AQP Demo: Soils Summarized by Bedrock Kind read more Related To leave a comment for...
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