Latest Contributions by ChrisDonohue__GISP

The trick to processing all the rasters is to employ an Iterator in Modelbuilder. This will allow the looping through of each raster. Here's the Modelbuilder Iterators: A quick tour of using iterators—Help | ArcGIS for Desktop  Accessing iterators in ModelBuilder—Help | ArcGIS for Desktop  Example of using an iterator in a model—Help | ArcGIS for Desktop  Note, however, if you are conversant with Python, that would probably be more effective than using Modelbuilder (Modelbuilder can be a bit quirky). Chris Donohue, GISP ... View more

For the Null issue, consider using SetNull (Spatial Analyst): Set Null—Help | ArcGIS for Desktop    Example from the Help: Using an Expression: To set any cell with a value greater than 5 to NoData and have the remaining cells retain their original values, the following parameters could be used on the tool dialog box: Input conditional raster : InRas1 Expression : "Value < 5" Input false raster or constant value : InRas1 Output raster : setnull_1 The equivalent using an expression in Map Algebra is as follows: OutRas = SetNull(InRas1 < 5, InRas1) Source:  Setting values to NoData with Set Null—Help | ArcGIS for Desktop  As to incrementing the other values up by one, I believe the Raster Calculator would be the way to go, using Map Algebra. What is Map Algebra?—ArcGIS Help | ArcGIS for Desktop  Example from the Help: Operators can accept a mixture of rasters and numbers. For example, the following adds a constant value of 8 to all the cells in the input raster: outRas = Raster("inras1") + 8 Source:  A quick tour of using Map Algebra—ArcGIS Help | ArcGIS for Desktop  Chris Donohue, GISP ... View more

If you have access to the Spatial Analyst extension, one way is to use the Conditional geoprocessing tools An overview of the Conditional toolset—Help | ArcGIS for Desktop  You can also access the Conditional (Con) functions in Raster Calculator: Raster Calculator—Help | ArcGIS for Desktop  There are some other possibilities, but it depends on what you would like to do.  Can you provide more details on what you are trying to change? Chris Donohue, GISP ... View more

Topology is usually the best method, but here is an additional option: Integrate—Help | ArcGIS for Desktop  Note that this tool modifies the input data, so make a backup copy of the source data before running it. Chris Donohue, GISP ... View more

What is at stake While most of the aspects of the proposed bill seem to be worthwhile goals, the specific mechanism of how work is contracted is detrimental to many GIS practitioners.  As provided in the current bill, federal contracting would be limited to only Architectural and Engineering (A&E) firms.  All GIS work would have to be overseen by a licensed Surveyor, Engineer, or Architect.  Many GIS firms and organizations do not have a licensed Surveyor, Engineer, or Architect on staff, as such staff are not needed for the type of GIS work being provided, so having such an archaic requirement would be onerous. History repeats itself? The is the same issue that came up with the MAPPs case in 2007, a contentious case that roiled the GIS and Surveying world at the time.  For those who didn't experience that one, it is good to read the legal background to get a sense of what is at stake and why this is so important to many GIS practitioners.  This case rocked the GIS world at the time. 2007 MAPPs case: http://www.aag.org/galleries/gis-procurement-files/2007_02_12_MAPPS_Case_Legal_Briefing.pdf  ArcNews Spring 2007 Issue -- MAPPS v. United States  Note that the 2007 MAPPs case was ultimately thrown out by the court due to lack of standing, but not after lots of acrimony. http://www.aag.org/galleries/gis-procurement-files/2007_06_14_MAPPS_Decision_EDVA.pdf  Going forward - should we be concerned? So back to the current bill.  On the pragmatic side, so far the current Geospatial Data Act of 2017 looks like it is very unlikely to be implemented: "According to GovTrack, the bill has a 1% chance of being enacted according to an analysis of the bill’s text by Skopos Labs." Source:  https://www.gislounge.com/aware-proposed-geospatial-data-act-gda-2017/  So while the potential consequences of the bill if enacted are severe, it looks unlikely to happen. If the bills authors do decide to move it forward, hopefully they will amend the archaic contracting requirments to make it more realistic. Chris Donohue, GISP ... View more

Just thinking about this brings up a question - does the Utah law expect even geocoding to be suppressed for use in locating addresses?  If someone already knows that your example judge lives at 150 Penny Ln, couldn't they find it anyways with other search mechanisms?  Splitting the street segments and re-ranging could be quite a tedious task if one had to account for many restricted addresses. You may want to contact ESRI Support with this one to see if any technical work-arounds are available.  Alternately, if you are going to the ESRI Conference, bring along some sample data and pepper the ESRI staff with this challenge in the Exhibit Hall Some other general thoughts - I'm not a lawyer and you probably already thought of this, but on the legal side, you may want to confer with your clients legal counsel if they are willing to discuss this issue.  One question I would have is what level of care is needed with this sort of thing for you and your clients (which if I remember correctly are municipal).  Is there additional potential liability that comes with the restricted address process? Likewise, if there is a high level of care required, a consideration for you as a private entity would be if additional compensation that might be needed to cover the required work and also for any additional liability that you may now be incurring. Chris Donohue, GISP ... View more

I don't have a technical solution to this, but did want to share that we had a somewhat similar issue in California a few years ago that caused many headaches.  State law at that time was changed mandating that addresses of government officials and public safety could not be handed out to the public.  But this resulted in a different outcome than what was intended. The Counties Assessors offices (who do most of the addressing) all realized it would be almost impossible to maintain an accurate list of all the government officials so they could suppress them, since the law was written so broadly that anyone who was appointed as even a low-level Committee member on a town or county board would have to have their information suppressed everywhere they owned property in California.  With 39 million people and continuous change in committee/board memberships that happen at all times of the year, it would be impossible to maintain an up-to-date list. I believe it was also an unfunded mandate.  So lots of good intentions with the law, but a lack of understanding of the reality of making it work. So the result was that most Counties would no longer provide public address information at all, since they realized they would be immediately out of compliance.  You would go to their web site and they would have a big disclaimer stating why address information was no longer available.  Several months later the Legislature modified the law, so now Counties are giving out address information again. Chris Donohue, GISP ... View more

A possible source of confusion - there are 3 Clip tools in ArcMap: The one Jake Skinner suggested (Clip - Analysis toolbox) is the one to use - it does raster.  The more commonly used Clip tool (Clip - Data Management toolbox) is for vector data, so that may be the source of confusion. Then there is a Clip tool for Coverages (Clip - Coverages toolbox). Chris Donohue, GISP ... View more

I have another potential solution to throw out there, but would need someone who is really good at 3D/Spatial Analyst to flesh out the specific tools.  Here's the general workflow: 1.  Invert your DEM. How To: Invert a surface using ArcGIS Spatial Analyst  2.  Use the Hydrology Tools to derive the streams (this will take take several process steps).  This will essentially derive your ridgelines.   Deriving runoff characteristics—Help | ArcGIS for Desktop    An overview of the Hydrology toolset—Help | ArcGIS for Desktop  3.  Once you have the streams, flood the area 100 feet.  (I'm not sure how to do this part) 4.  Invert the data back. Let me add some folks who I suspect know some or all of how to do this: Dan Patterson  Curtis Price  Xander Bakker  EDIT - added more information / clarified sentences Chris Donohue, GISP ... View more

I have a theoretical workflow that may work (untested), assuming you have an Advanced ArcGIS Desktop license: 1.  Use Feature Vertices to Point with the Point Type (optional) set to "Mid" to get the midpoint of each line. 2.  Use Create Thiessen Polygons (Analysis) on the points from step 1. 3.  Dissolve (Data Management) the resulting polygons based on each group to come up with the final polygon.  Note - you may need to first spatial join or select by location the original point information to be able to provide differentiation for the Dissolve (ie so when the Dissolve is run all the polygons representing violet lines dissolve into one polygon, all the polygons representing magenta lines dissolve into one polygon, etc. Chris Donohue, GISP ... View more

All our data has is "On Street" There does not appear to be an "On Street" field in the example.  Can you elaborate on what is in the "On Street" field currently?  Does it contain the street address ranges?  If so, it may be possible to write a script to extract out the "To Street" and "From Street" values from the "On Street" field.  However, we will need to be able to see the data and how it is arranged in the "On Street" field to evaluate this and come up with the correct code. If the "On Street" field does not contain the range and there are no other fields in the data that contain the street address range information, then the challenge will instead be to derive the ranges.  This may be possible if you have other data.  For example, if you have address range data in an Intersection points layer, it can be spatial-joined to the lines and then calculated across.  Again, it will depend on what data you have and how it is arranged. Chris Donohue, GISP ... View more

Just a thought - would it essentially be the same if you add 1 meter to your DEM only in the horizontal extent of the stream?  If so, you could probably do this with Raster Calculator. Chris Donohue, GISP ... View more

To help solve this, what sort of information is in "On Street"?  Is the "To" and "From" address range there?  Addressing  Chris Donohue, GISP ... View more

I've also run into this issue in the past of needing to capture the layout extents and had not found an easy automated solution.  In the past when there are just a few mxds to capture the layout extent I've just ended up buckling down and digitizing the extents as polygons while in layout view.  If there is not currently a solution, this could be a fallback.  Painful, but it doesn't take that long. Chris Donohue, GISP ... View more