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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


2d
comment How to perform a weighted overlay analysis with categorical classed data?
Since this is not a suitability type analysis I am not sure that a weighted overlay is at all the appropriate approach. You may want to investigate a weighted Kappa.
Nov
24
comment Aggregate table with dates and average geographic coordinates
The base function to apply a function to a conditional factor is ?tapply
Nov
21
comment R geographically weighted regression GWModel
I would remove the inhibit interpretation of X^2. Often you have to parse a formula when writing a function and perhaps the I() is not being interpreted correctly in the funciton.
Nov
21
comment R geographically weighted regression GWModel
Per my second recommendation, try to specify the @data slot for your data argument. I will add some references to my original post. As far as model options, I would highly recommend a mixed effects model. You can specify a spatially lagged y, an autocovariance/autocorrelation term or a polynomial of [y,x] as the random effect. This will decorrelate the error and reveal the underlying linear relationship. Keep in mind that GWR is specifically a model for second order effects (nonstationarity) and if you are after a first order effect it is quite inappropriate, invariant of its validity.
Nov
21
answered R geographically weighted regression GWModel
Nov
21
comment Classified Images of RandomForest-Classification look clustered
This I completely agree with. I would add, building on @morbidmitch evaluation, that it is a misnomer that RF does not overfit. If there is significant correlation in the ensemble, often caused by lack of independence in observations, you will have an overfit problem.
Nov
21
comment Classified Images of RandomForest-Classification look clustered
Both of your assertions are quite incorrect. Where it is not necessary to include naive spatial process [x,y], if there is anisotropy in the data, it can help account for trend. In regard to random forests, I am completely unclear as to what you mean. Given a literal translation, this is just wrong. Not only can you get multiple splits of a variable through a given tree, the model represents a bootstrap and is predicted through plurality. Both of these things make it inherently nonlinear. I believe that the linear artifacts are being caused by contrast differences in an image mosaic.
Nov
18
comment Why is the result of a raster calculation integer when it should be decimal?
To be safe, I would check the precision of NOT coercing to float on both sides of the equation. You may get some unexpected results, or not.
Nov
18
revised Why is the result of a raster calculation integer when it should be decimal?
added 8 characters in body
Nov
18
answered Why is the result of a raster calculation integer when it should be decimal?
Nov
17
revised Which Statistical Test to use?
added 1 character in body
Nov
17
answered Which Statistical Test to use?
Nov
16
awarded  raster
Nov
15
revised average certain raster cells in R
Change subtitted edits back because if function explicits. The reccomend change was not correct!
Nov
14
answered average certain raster cells in R
Nov
14
awarded  Revival
Nov
13
revised Map accuracy assessment by moving window in R
Changed example to Kappa output
Nov
13
comment Map accuracy assessment by moving window in R
Could you please add some more detail to your answer? Perhaps a brief worked example. Since you cannot pass a stack to focal, how would you apply a focal function to the "new-created rasters? Recommending matrix coercion of rasters is not the best advice because it will not keep the workflow memory safe. Other than smoothing, I am not clear on how assigning the mode to the focal cell allows a fuzzy assessment of accuracy. You would want to asses all the values in the focal window, which is consistent with the matrix algebra defined in Hagen-Zanker (2006 & 2009).
Nov
13
answered Creating buffer around particular raster cells using ArcGIS for Desktop?
Nov
13
answered Map accuracy assessment by moving window in R