Latest Contributions by ThomasDilts

‎08-28-2020

Hi Bill. Correct. It isn't hard to put together a tool that does this in ModelBuilder. I just think that it would be a nice one for Esri to include in their standard tools so that people don't have to build a model.

‎08-28-2020

I'm not sure that I 100% follow, but this is a very common workflow for me in Desktop. I frequently have polygons that I want to pull raster values to. Sometimes these are forest stands. Sometimes individual Landsat pixels. Points are fine, but many times having the individual footprints of the polygons are essential, especially with rasters where different rasters may have different cell alignments.

‎08-27-2020

Extract multivalues to points is a user-friendly easy-to-use tool. I'd like to see an Extract multivalues to polygons tool. Currently this can be done in one of two ways. The first option is to convert the polygons to a centroid point, run the extract multivalues to points tool, and then join the results back to the polygon. The other option is to run the Zonal Statistics as table tool and join those results back. Why not save a few steps and just create an Extract Multivalues to Polygons tool?

‎08-09-2019

I suppose that one way that this might get coded is by dropping one raster at a time in the stack and seeing if that breaks the tie. This could be done with python without having to modify the source code of the Cell Statistics tool. But ... I would still prefer if Esri just added these options to the Cell Statistics tool itself (NODATA, RANDOM, FIRST, LAST).

‎08-09-2019

I can think of how to implement the NEIGHBORHOOD option in Model Builder. FIRST, LAST, and RANDOM are trickier without knowing exactly how the underlying code in the cell statistics tool works.

‎08-09-2019

Cell statistics is an incredibly useful tool. When using the MAJORITY option the default behavior of the tool for dealing with ties (when the two most abundant values are of equal abundance) is to create NoData. This will often result in a map with lots of holes (NoData cells). I would propose adding at least three options for dealing with ties. One option would be FIRST. This would take the first value of the two tied values in the raster stack. Another option would be LAST in which it takes the last raster of the stack with the tied value. A third option would be RANDOM. This would randomly select one of the two tied values. Finally a fourth option would be NEIGHBORHOOD. This option would expand by searching a 3x3 neighborhood and using the MAJORITY cell in that neighborhood. If a tie couldn't be broken using a 3x3 neighborhood then a 5x5 neighborhood would be used, etc. until all cells have a value.

‎07-24-2019

The Wayback World Imagery service is a wonderful start, but nothing beats the ease of use of Google Earth's time slider. I would love it if Esri could adopt this more streamline approach directly into ArcGIS Pro and ArcMap. We spend a lot of time using both Google Earth and ArcMap side by side. It would be wonderful if we didn't need to use both simultaneously all of the time.

‎05-13-2019

Hi Kory, I didn't realize that this had been implemented in 10.6.1. It would be extremely useful to change some of the default extent settings for the other tools, watershed in particular. Thanks

‎05-13-2019

In general, intersection of inputs is the default extent for all tools. There are many tools involving points where this leads to truncated output. In these cases it would be more appropriate to have the default extent switch to something larger. In the case of the Watershed tool it should be the Flow Direction. For distance and density tools it is less clearcut, but it would make sense to buffer the points by a percentage of the extent or a fixed distance or something similar so that the user doesn't end up with truncated datasets. This could even be added as parameter in the tool overwriting the default extent.

‎05-13-2019

The Eliminate tool currently allows the user to dissolve selected polygons into shared polygons with the longest border. Several raster operations will create "pixel-polygons" or polygons that represent a single pixel. The Watershed tool is a prime example of this. These polygons may be connected to their neighbor by a single vertex, not a shared border. By increasing the number of options to users this could greatly reduce manual editing.

‎02-04-2019

Hi Luke. Thanks for pointing that out. I've updated the zip file so that it is no longer empty.

‎02-03-2019

Hi, I know that Luke and others have answered this question, but I also wanted to throw out there that I build a toolbox that does this and wrote a blog post on it. The tool is at: https://www.arcgis.com/home/item.html?id=fc7c1ca07e4844d7b722049b503b0fb2 and the blog post is: GIS Tools and Techniques for Landscape Ecological Research: Miscellaneous Hydrology Tools for ArcGIS - Find Longest Stre… The blog post is part of a series that describes the different tools in the Miscellaneous Hydrology Toolbox. -Tom Dilts

‎01-17-2019

Hi everyone, Sorry about the long delay. Converting the model to a python script did the trick. Now the tool iterates fine and works like a charm. Strangely, I still have no clue why the tool performs poorly as a model, but thank you everyone who contributed ideas. They were all helpful steps along the way. I'm expecting to a release a new geoprocessing toolbox sometime soon (Q1 of 2019) - the Lattice Connectivity Toolbox. The toolbox assesses habitat connectivity using a lattice or tessellation and a resistance kernel approach and is designed to serve as inputs into graph theoretic models. The toolbox is a refinement of the approach that I outline in a 2016 paper. Dilts, T. E., Weisberg, P. J., Leitner, P., Matocq, M. D., Inman, R. D., Nussear, K. E., & Esque, T. C. (2016). Multiscale connectivity and graph theory highlight critical areas for conservation under climate change. Ecological Applications, 26(4), 1223-1237.

‎11-19-2018

Thanks for the tips. It might take me a day or two because I've got to finalize the last step of the process. I tend to start out in ModelBuilder to figure out the steps that I need to take before jumping to python (unless I know that it is going to involve a double loop).

‎11-19-2018

Hi Curtis. Thanks for making that distinction. Originally I had not turned off turn off add geoprocessing results to display in Geoprocessing / Options but just had removed the layer as a parameter in the model. I've since tried running it with your suggestion of turning it off in the geoprocessing options from the geoporcessing menu in ArcMap as well, but to no avail. My next thought is to try exporting to python and re-doing the coding for the looping (does looping ever just work straight from ModelBuilder export?).

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My Ideas

Latest Contributions by ThomasDilts

Re: extract multivalues to polygons

Re: extract multivalues to polygons

extract multivalues to polygons

Re: Add options to deal with ties in cell statistics tool when selecting the majority option

Re: Add options to deal with ties in cell statistics tool when selecting the majority option

Add options to deal with ties in cell statistics tool when selecting the majority option

Add ArcGIS Time Slider to ArcMap/Pro

Re: Change default extent on the Watershed tool, density tools, and distance tools

Change default extent on the Watershed tool, density tools, and distance tools

Add "share single vertex" option for the Eliminate tool

Re: using the Flow Length tool in Spatial Analyst's Hydrology Toolbox to find the Longest Flow Path

Re: using the Flow Length tool in Spatial Analyst's Hydrology Toolbox to find the Longest Flow Path

Re: Model runs fine in ModelBuilder but hangs in tool mode

Re: Model runs fine in ModelBuilder but hangs in tool mode

Re: Model runs fine in ModelBuilder but hangs in tool mode

Re: Align Rasters

AIC in ArcGIS Pro MaxEnt

Create a searchable website showing which updates ...

New toolbox in Spatial Analyst that transforms ent...

extract multivalues to polygons