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I am a senior landscape ecologist with The Nature Conservancy's, Central Science. I attempt to bring vigor from diverse fields such as landscape ecology, spatial statistics, remote sensing and applied mathematics to answer practical conservation questions. I hold Affiliate Associate Professor status at University of Wyoming and have over 65 publications in peer-reviewed journals.

My research is focused on spatial statistics in ecological applications, species distribution modeling, climate change, landscape genetics, Bayesian statistics, Lidar and spectral remote sensing and gradient modeling. I have ridden horses for 35 years and was a member of the US Equestrian team. I have also played guitar in several swing and bluegrass bands


Jul
17
answered R SP library: identicalCRS and parameters in different order
Jul
15
reviewed Approve suggested edit on Save As in QGIS 2.4
Jul
15
reviewed Approve suggested edit on Process to georeference corners of vector file?
Jul
10
reviewed Approve suggested edit on Looking for free tools to automatically generate spatial data catalogue
Jul
9
reviewed Approve suggested edit on Python Hyperlinking Script in Arcmap 10.2
Jul
8
comment Negative Topographic Index Values
There should not be negative values in TWI/CTI. It could be how the programmer decided to deal with 0 slope values or the value associated with non-aspects, which are often -1.
Jul
6
answered Calculating the fractal dimension of a line segment
Jul
4
awarded  Revival
Jul
4
answered How to access each raster in a stack with a loop
Jul
4
reviewed Approve suggested edit on Calculate distance of downstream trace (geometric network) using ModelBuilder iterator
Jul
3
answered How to mosaic rasters in R?
Jun
28
awarded  Yearling
Jun
23
answered Step-by-step: How do I extract Raster values from Polygon overlay with Q-GIS or R?
Jun
22
comment R plot raster with real colors
You are using the raster() function which is only intended for single band rasters. If you use stack() or brick() then your three RGB bands will be in the resulting raster class object. You will still need plotRGB to display the composite image.
Jun
18
comment How to group individual groups of pixels into a single class
Agreed, however this is a limitation of the convex geometry algorithm employed by ESRI. Take a look at the Pateiro-López & Rodríguez-Casal (2009) Alpha Convex Hull method in this thread (gis.stackexchange.com/questions/1200/…). You can adjust the alpha parameter to better fit your data.
Jun
18
answered How to group individual groups of pixels into a single class
Jun
18
comment How to group individual groups of pixels into a single class
This is not a hard-and-fast solution. Focal statistics relay on a neighborhood and as such will expand the outer boundary in potential undesirable ways.
Jun
18
revised Error in which.max() : not yet implemented for large objects in R
added 541 characters in body
Jun
18
comment Error in which.max() : not yet implemented for large objects in R
Please edit/modify your original question to expand and do not post an answer! Are you saying that your OS is 32bit? If you are working with spatial data in R a 64bit OS is a must. If you are in a 32bit OS then you may want to play with the rater packages default setting for blockSize. I edited my answer to demonstrate a custom read/write function using blockSize().
Jun
18
comment How to obtain a DTM/DEM from DSM
My point was that you could try applying filtering methodology developed for lidar point clouds to your DSM after converting them to points. You would in essence, have a systematically sampled point cloud and some filtering algorithms may work. I believe that my MCC algorithm would work if you played with the model coefficients.