Latest Contributions by ChrisDonohue__GISP

‎01-21-2015

I have run into weirdness like this in the past when deriving Service Areas with Network Analyst. Sometimes it seems to have a mind of its own and produces strange results. Just to be on the safe side, though, if you haven't done it already I would run topology on your data to ensure it all is connected correctly. Sometimes it seems like having just one disconnect in an otherwise connected dataset causes the strange results. For example, a break in connectivity in your lower image at or near the junction of Peachtree and Meadowbrook might yield the result you have. Keep in mind that often the lines/edges will look connected when inspected visually, but topologically be off by a very small amount, rendering them unconnected from Network Analysts' perspective. Another solution that sometimes works is to replace the linework in the area where it is weird. Draw in new and delete the old, attribute as necessary, then run topology to ensure connectedness. Then run it with Network Analyst. I don't know why this resolves it in some cases, but it can sometimes fix the issue. Chris Donohue, GISP

‎01-14-2015

Just an idea (not tested) based on other posts by folks here on GeoNet with a similar challenge: Extract out the 4 points for the intersection as its own feature class. Create a polygon from the "Minimum Bounding Geometry" bounding box. Find the centroid of that polygon (Feature to Point) Resource for the Minimum Bounding Geometry part: Buffers With Points - A Tool for Creating Rectangular Buffers | GISNuts.com Chris Donohue, GISP

‎01-14-2015

I'll add the following on a related area of confusion regarding the Student software installation in case someone finds this post. Not sure if this has been resolved recently, but this was an issue with the Student software last year and the year before. When registering the student software, you get to a point where it asks if you want to authorize the extensions. The student software does indeed come with access to several extensions, however, oddly enough, you do not want to authorize them at this point. If you do authorize them, the install will bomb out. Instead, continue the process without authorizing any of them. When you finish, the extensions will be available to turn on. Chris Donohue, GISP

‎01-14-2015

Glad to be of help. Chris Donohue, GISP

‎01-14-2015

I think "Con" might be a better way to go than "SetNull" for what you are trying to do. You can run Con as a tool or in Raster Calculator. Con can also be used like SetNull: If no input false raster or constant is specified, NoData will be assigned to those cells that do not result in True from the expression. Con (Spatial Analyst) ArcGIS Help 10.1 Chris Donohue, GISP

‎01-08-2015

Mike has it - SetNull is the way to go. If you don't want to run the SetNull Tool, but instead prefer to Raster Calculator, it can be done there also. On the right side of the Raster Calculator will be a group of tools. You can find SetNull under "Conditional". It is visible in the picture they have at the start of this Help article: Raster Calculator ArcGIS Help 10.1 The syntax in raster calculator is something like this: SetNull (in_conditional_raster, in_false_raster_or_constant, {where_clause}) Chris Donohue, GISP

‎01-08-2015

I'm running into an issue with Metadata and SDE. I'm not an expert on SDE, so was wondering if folks had run into this, and if so, what they do to address it. I recently created a Version and made some edits, then looked at the Default copy of the Feature Class and the Metadata for Default shows the changes I made to the Version! These changes include both manual updates to the metadata and the automated geoprocessing updates to the metadata. This is a bit disturbing, to say the least. Default is supposed to be a static copy of your data. However, any changes you make to your Version are immediately applied to the metadata of Default, resulting in mismatch of metadata and data. Plus the metadata changed without a review - i.e. this happens immediately, not even waiting for a second-party review at the Reconcile and Post steps. So file control and Data integrity are an issue. I discussed this with ESRI Tech Support this morning and they say its a known issue since 2006. Unfortunately, there is not currently a timeline to fix it, though it is already on their bug/enhancement list. From what ESRI told me, the way Metadata is implemented in SDE is as a single file associated with the Default feature class. However, unlike the data it documents, it cannot be Versioned. So anytime anyone creates a Version, they are directly impacting the metadata. And, of course, being that SDE is a multi-user database, think of the havoc of several people all working on a Version of the same feature class - the metadata is immediately getting altered by all the Versions. In that situation, a user who accesses the Default feature class might find the metadata to be bizarrely mismatched to the data they are seeing. In terms of workarounds, the metadata in SDE cannot be locked to prevent the changes. So the reality is that when you work on a Version in SDE, you are changing the metadata for Default, whether you realize it or not. So my questions are these: - Has anyone else noticed this? - Has anyone figured out a workaround to protect the Metadata from being altered until the Version is ready to be finalized (i.e. it was reviewed in Reconcile and Post and is now ready to replace Default)? Chris Donohue, GISP

‎01-08-2015

Maybe Daniels' idea 1 (contours) could be modified to make it workable? An idea I'll toss out: 1. Create contours, but based on elevations (not gradient). 2. Derive the 15%+ slopes and convert to polygons. 3. Now Dissolve the polygons. 4. Clip the contours based on the Dissolved slope polygons to find only the contours in steep areas. 5. Run Feature to Polygon to convert the clipped contours to polygons if they do indeed circle an area. Not totally sure this last step would work, but may be worth a try. Caveat: Even if this works from a topological perspective, it won't work if the steep areas that encircle a butte vary in elevation as they encircle it. So it will be limited by the morphology/geology of your study area. For example, if the butte's are in a sandstone formation with a substantial dip (angle), this won' be effective. Chris Donohue, GISP

‎01-07-2015

If you have a license level of "ArcGIS for Desktop Advanced" (ArcInfo), a possibility would be to use the "Identity" tool. ArcGIS Help 10.1‌ The line layer would be the Input Features and the buffers would be the Identity Features. The result is essentially a new line file like the original, but with the attributes of the buffer tacked on. One caveat - this process will split your linework where it crosses buffer boundaries. If you have a static length field, you will need to recalculate the Lengths. Chris Donohue, GISP

‎01-07-2015

I think Xanders' idea has potential. Use a line or polygon feature class showing where the cattle could be initially as part of the Cost Distance Analysis. For example, assuming the islands issue is only buttes/mesas/high elevation areas, you could make the Cattle Starting Locations polygon feature class by just selecting low elevations, then doing the Cost Analysis as Xander suggests. Obviously this will be dependent on your data. Chris Donohue, GISP

‎01-07-2015

Hi all: I was wondering if anyone has gone through the process of creating a Topology process in Modelbuilder. I've been handed a project with several layers that look like they will need topology run on a monthly basis, so I was thinking of taking a stab at automating the Topology process. I noticed that ArcGIS 10.2.1 has a Topology toolset, so this looks possible. The topology would be run with rules against either SDE or feature classes in a File Geodatabase (haven't decided yet which way to go). Has anyone pulled together a model that does topology? If so, any weirdness to look out for or advice you can offer? I'm trying to get a feel for what issues may crop up before I dive in on this. Thanks in advance, Chris Donohue, GISP

‎01-07-2015

I saw a thread on this, which may be of help. Have not tried it myself, though. Adding Zoom to Selected feature to execute at the end of model. Chris Donohue, GISP

‎01-06-2015

Interesting challenge. I don't have a specific answer, but I'll throw out a solution for folks who have a similar issue. If you had regular numbers (integers) instead of station numbers you could add a field for your new ID's and use field calculator to populate the new field based on the highest value minus the current value. For example: [New ID result] = (highest ID number + 1) - [OldID field] So, for example, if you had 6 ID's originally: (6+1) - 1 = 6 (6+1) - 2 = 5 (6+1) - 3 = 4 (6+1) - 4 = 3 (6+1) - 5 = 2 (6+1) - 6 = 1 Chris Donohue, GISP

‎01-06-2015

I've run into the same issue and am also curious if there is a way to resolve this besides Erase. It appears the main issue is that their is no way to have the label engine recognize that no labels should be placed in a polygon. Instead, they will be prevented from being placed on the outline (only): "Setting a feature weight of high for point or line features ensures that no labels will be placed on top of these features. Setting a feature weight of high for polygon features ensures that no labels will be placed on the outline of these features." Source: ArcGIS Desktop Is there some way to make a polygon a sort of exclusion-zone for labels? Chris Donohue, GISP

‎01-06-2015

I'm not sure if it can be done in ArcMap 9.3, but as a workaround, you could create the legend in an image program or Excel, and then import it into ArcMap. For example, one way I've done this is to save the ArcMap map as a jpg, then use Photoshop to cut up the gradient rectangles for each portion of the legend. Then combine them all in Photoshop, add text and borders, and save as a jpg. Import the jpg into ArcMap and place it with the other legend items. Tedious, but do-able. If you didn't need the gradient effect, it could quickly be built in Excel, then "Copy as picture" (not the regular Copy or the background guide lines may transfer across), then Paste into ArcMap. Chris Donohue, GISP

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Date Last Visited	‎08-03-2022 01:39 PM

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Latest Contributions by ChrisDonohue__GISP

Re: Service Area analysis - holes in service areas

Re: Generating the centroid of multiple points

Re: License Difficulty - Student Membership

Re: How do you use SetNull to set a range of values to a single value in a raster?

Re: How do you use SetNull to set a range of values to a single value in a raster?

Re: Need to convert zero values in a raster to "NoData"

SDE issue - Metadata of Default changes when operating on Versions

Re: Remove Islands

Re: Add buffer layer data to line layer

Re: Remove Islands

Has anyone created a Topology process in Modelbuilder?

Re: Zoom to in Model Builder

Re: Inverse a route station numbering

Re: Labels Overlapping

Re: custon legend in arcmp 9.3

Re: ArcGIS 10: Graphics won't display in Data View

Re: Can't set output as intermediate data

Re: Addressing - Plus Code or What3Words (W3W)

Re: How to label "_, Mount" as "Mount _" ?

Re: Raster/Vector Land use Analysis

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