Latest Contributions by DaveVerbyla

I will be teaching a graduate eLearning class starting January 2018 on Remote Sensing Applications Using Arcmap. NRM641 Remote Sensing Applications Using ArcGIS Spring 2018 3 credits https://elearning.uaf.edu/courses-code-keep/course-details-17-18/?crn=35760 COURSE GOALS: 1) To use ArcGIS to explore changes in Alaska associated with climate warming in Alaska including greening of the arctic, browning of the boreal forest, mapping wildfire severity and hotspots, mapping shrinking lakes and coastal erosion, etc. 2) To learn basic image processing methods using ArcGIS including panchromatic and color image display, image fusion, image georeferencing, change detection methods, supervised and unsupervised classification, and accuracy assessment methods. 3) To learn about sensors especially applicable to vegetation applications in Alaska including color infrared aerial photography, LIDAR, IFSAR,Landsat, MODIS, and AVHRR sensors and data products.. I offer this course spring of even number years (I teach the E-Learning grad class Python scripting in ArcGIS spring of odd number years) email me if your interested: dlverbyla@alaska.edu Thanks. Best Regards, Dave Verbyla Professor of GIS/Remote Sensing School of Natural Resources and Extension ONEILL 368 University of Alaska Fairbanks http://www.dverbyla.net/ ... View more

I am new to Python toolboxes.  I have 2 parameters,  param0 is an input text file, param1 is an output feature class. I want param1 disabled, which works fine, once it is enabled, I want it blank, but it is populated with "C:\Users\Dave\Documents\ArcGIS\Default.gdb\test_CreatePolygon"     def updateParameters(self, parameters):         """Modify the values and properties of parameters before internal         validation is performed.  This method is called whenever a parameter         has been changed."""         if ( parameters[0].value):             parameters[1].enabled = True             parameters[1].value = ""         return ... View more

Allow temporal animations based on numeric fields such as hour of day (showing lightning activity peaking in late afternoon), week of day (showing recreation peaking on weekends), or  century field (showing glacial recession over the past 2000 years by century).  Current the time slider seems restricted to a datetime field and in many cases the important temporal aspect is hour of day, week of day or decade or century. ... View more

I have some large ascii rasters output from models that are essentially 0 or 1 pixel values. For example: NCOLS 2 NROWS 2 XLLCORNER 0 YLLCORNER 0 CELLSIZE 1000 NODATA_VALUE 0 1 0 0 1 The ASCII to Raster tool outputs to a 32-bit signed integer raster, when really these values can be represented by a 1-bit raster.  Seems like an inefficient way to go!  Is there some other ASCII to Raster tool (in GDAL?, Python Imaging Library?) that is more efficient in importing ASCII data into rasters? ... View more

I have 200 rasters with fields value, count, a,b,c I need to compute max(rasters.a)                          max(rasters.b)                          max(rasters.c) where rasters is the list of 200 rasters, and a,b,c are fields I need the max for each pixel...similar to using the Cell Statistics tool which apparently only works with the value field? ... View more