8,555 reputation
1546
bio website dmahr.com
location United States
age 26
visits member for 3 years, 8 months
seen 49 mins ago

I'm a Senior GIS Analyst at The Cadmus Group, in Waltham, MA, with experience using geographic information systems and remote sensing in environmental science applications. This includes geospatial decision support, hydrographic analyses, climate change assessments, land use change studies, and demographic modeling. I'm responsible for implementing technically demanding large-scale data analytics workflows and developing custom geoprocessing tools for ArcGIS with the Python programming language. My work at Cadmus has supported EPA’s Office of Research and Development, EPA’s Office of Wetlands, Oceans, and Watersheds, EPA’s Office of Ground Water and Drinking Water, the US Army Corps of Engineers, the US Agency for International Development, and public and private electric utilities, among other clients.

Find me on LinkedIn or check out my blog.


Jul
2
awarded  Autobiographer
Jul
1
comment Cutting a circular buffer via Arcpy
@EmilBrundage Nice script! One alternative for ArcGIS 10.2+ is to use the buffer() and cut() methods of the arcpy.Polygon class to perform the geometry operations instead of using geoprocessing tools. This shouldn't affect the output, but it is probably faster.
Jul
1
answered Directional Spatial Join with Python - Arcpy
Jul
1
comment Directional Spatial Join with Python - Arcpy
Do you want to join the centroid to the closest polyline along each of those exact bearings? Or just in each quadrant?
Jul
1
revised Directional Spatial Join with Python - Arcpy
Fixed bullets
Jun
9
comment Create Complex Polygon from Point Layer using only Boundary Points in ArcGIS
What you want is a concave hull, which is not natively available in ArcGIS, unlike convex hulls. If your point spacing is fairly small, you could use Euclidean Distance > Reclassify > Expand > Raster to Polygon or Aggregate Points.
Jun
9
comment ArcMap 'in_memory' trouble?
Good detective work. This is probably because in_memory datasets are treated like geodatabase feature classes, which (I now remember) cannot start with numbers.
Jun
9
comment ArcMap 'in_memory' trouble?
Have you tried running RasterToPolygon_Conversion() with output to an in_memory dataset in the ArcMap GUI? Some geoprocessing tools (e.g. project) don't allow outputting to in_memory datasets.
Jun
2
comment How to Remove Multiple Labels for Stacked Points? ArcGIS 10.2.2?
@arzola I added an alternative/workaround solution that does not use Maplex.
Jun
2
revised How to Remove Multiple Labels for Stacked Points? ArcGIS 10.2.2?
added 1205 characters in body
Jun
2
answered How to Remove Multiple Labels for Stacked Points? ArcGIS 10.2.2?
May
27
awarded  Excavator
May
27
revised Dissolve polygons - group to others with touching corners
Adding alternative approach to exploding multipart to singlepart using geoprocessing tool
May
27
comment Checking if Terrain Model has pyramids or data sources using ArcPy/Python?
Can't you use the skip_existing parameter in arcpy.BuildPyramids_management() to not build pyramids for the rasters that already have them? The other workaround that I've used is to check for the presence of .ovr files, though this doesn't work with geodatabase rasters.
May
22
revised Can I reproduce this classic cartographic hillshade relief effect (hachures) electronically using modern DEM data?
deleted 81 characters in body
May
18
comment Creating bathymetric contours using shoreline point data and transect point data
You're seeing the "pinching" because the interpolation tools in ArcGIS are naively interpolating based on point locations without any regard for hydrologic processes, sedimentation, etc. For this reason, more specialized bathymetric interpolation tools are probably needed to create a robust result unless you have many transects. This question goes into some of the other options. There's also a lot of literature about bathymetric interpolation.
May
16
comment How to calculate the distance to the nearest coastline from site locations?
For those without an ArcGIS for Desktop Advanced license (formerly ArcInfo license), this can be accomplished with the Spatial Join tool. The target_features would be the points, the join_features would be the coastline, and the match_option would be CLOSEST.
May
16
revised Debugging AttributeError: 'Result' object has no attribute 'save' from ArcPy script?
Added code indentation and syntax highlighting
May
15
comment Headings in legends
+1, clever workaround!
May
14
answered Headings in legends