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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


Dec
17
reviewed Approve Save a layer for each unique value using Python in QGIS
Dec
16
revised combine rasters into single raster with multiple field values in R
added 125 characters in body
Dec
16
revised combine rasters into single raster with multiple field values in R
added 113 characters in body
Dec
16
comment combine rasters into single raster with multiple field values in R
For NLCD the bit-depth creates a 0-255 range of values but only certain values are related to landcover classes. All yo need to do is to turn non-attributed values to NA. Since the numeric values are nationally consistent, you do not need the text attributes. I am not sure why you have multiple bands, unless the data is multi-year, it should be a single band not RGB.
Dec
16
comment combine rasters into single raster with multiple field values in R
BTW, you should check the validity of this solution. Since the placeholder class for this empty slot is list(), I would imagine that any functions intended for this slot is depending on this specific object class.
Dec
16
comment combine rasters into single raster with multiple field values in R
So, the question here is what are you going to do with this? Since raster objects operate in a different way the sp objects, I am not clear on the intention. You have just negated the memory safe aspects of a raster object and are storing the value attributes twice. With this solution, you may as well coerce to an sp object and operate directly on the pixels in a given function.
Dec
16
revised combine rasters into single raster with multiple field values in R
added 2 characters in body
Dec
16
answered combine rasters into single raster with multiple field values in R
Dec
15
awarded  Enlightened
Dec
15
comment Using R with ArcGIS Desktop
You know that Mark's scripts are depreciated, correct? The logistic function calls two depreciated functions and the cluster tool relies on a package that no is no longer maintained and as such, is not available at R >= 3.0.0. Given that R is at 3.1.2, users will likely get nothing but errors when running through your example. I have rewritten these scripts with several notable improvements including an autologistic model and silhouette optimization using a K-medoids clustering algorithm. If you would like the scripts, let me know and I will aim you to the download.
Dec
15
awarded  Nice Answer
Dec
15
comment Raster to polygon using R
You are pretty scant on details. Perhaps there is a good reason that this particular raster is causing bad behavior in rasterToPolygons. Memory shortages do not commonly cause a crash so, it is concerning that rasterToPolygons is causing a computer crash. R is carefully constructed to avoid this and in looking at source this is just a function and not compiled code. Can you please provide some details about your raster (nrow, ncol, format, disk size, how is it being read in...)? As @Sapcedman suggested, have you tried a subset?
Dec
11
comment how to convert list of stack images to timseries files in R
It would not be a very memory safe approach but, you could read the rasters in using readGDAL in rgdal. This results in a SpatialPixelDataFrame object where each time step is a column in x@data (time=column, pixel=row). You would then iterate through each row (pixel), coerce to a vector then ts object and pass it to the desired function in bfast. I should point out that ?bfast has a clear example of using NDVI data in a timeseries analysis with the function.
Dec
9
answered ERROR in Resolution Merge using ERDAS IMAGINE 2013
Dec
9
awarded  arcgis-desktop
Dec
8
answered Accuracy assessment using polygons as reference data as against point data?
Dec
8
answered Identify shadow on Landsat image by Hillshade Tool (spatial analysis) in ArcGIS?
Dec
8
comment Best way to make a fake hillslope?
possible duplicate of How to generate a random but believable digital elevation model?
Dec
5
comment Map accuracy assessment by moving window in R
I used a p threshold to make the answer a bit broader in application. Often a binary response is derived from an estimated probability distribution. This is only relevant to the block of code where I am creating example data and does not relate to the implementation of the moving window Kappa. If my answer works for you please marked answered so we can close this thread.
Dec
4
comment Convert coordinates from readShapePoly in R to long-lat coordinates
You do not have the same control as gCentroid, but SpatialPolygons hold the centroid in the object. You can retrieve them as a matrix using: coordinates(map_wgs84)