Latest Contributions by XianyingFan

Thank you so much Bill! We will try in our computer and get back to you if there is any further question! ... View more

Hi  Bill, with the help of an incredibly nice friend's help, we have a draft python code to work with. The attached includes a test geodatabase & a test script (traceGeometric.py). Unfortunately, the script works, so far, on the first feature (dam) only. It does assign a closest gage ID. By the way, there are two fields with reachcode  info. of gage points because I snapped it to flowline feature class and I think using REACHCODE is the right field as gages ID instead of REACHCODE2. Here is what she wrote about the current issue of the code: --------------------------- After the first dam, "TraceGeometricNetwork" tool fails. The problem is, I think, the output Network/layer group. In m script, the output has to be the same as the input network, Hydro_Net. I've seen other examples and they seem to be able to create a new output. I think it would let the script to run against the rest of the dams if I can use a different output (but not so sure). The tool seems to be very picky, unfortunately. Anyway, I will share what I have so far and let you play with the script. PS: my script runs directly from Python shell (2 not version 3, because ArcGIS doesn't use 3..), without opening ArcGIS (but you have to have ArcGIS on your local machine) and it's on Windows - below is the screenshot of the output. ----------------------------- Can you please take a look at our data and python code how can we address the issue? Many thanks! ... View more

Thank you very much Bill! Here is the data. For the two options that you mention: Option1: I am able to trace downstream of one dam point using the Geometric Network Analysis Toolset and then join the selective line features with gage points to get the closest gage point info. My difficulty is to write the python code of the tracing process and automate to other points; Option 2: I accept the logic of treating the flowline as one way street and use the Network Analysis Toolset (specifically: find closest facilities tool) to find the closest points for all dam point at one time, however I failed to get the result because I can't find a way to set the direction so that it will find the closest facilities downstream along the flowline. ... View more

Hi Bill, Excited to see you're back! How can I share the zip file? I saw insert image, insert video, insert link, but no insert files. Can I send directly to your email? Many thanks! ... View more

Hi Lauren, Were you able to get the result? I have a very similar task, can you share you experience how you finally achieve your result? Thank you very much! Maggie ... View more

Hi Bill, did you see my last comment? I tried to build network dataset, however, I encounter an error: "Network was build, but with some errors. The network can still be used in analysis, however the invalid features will not participate in the network", when I opened the "show build errors", I found that all my dam and gage points are listed there, so those points weren't able to participate in the network. Did you encounter this problem before? ... View more

Thanks a lot, Bill! If using network analyst toolset, how can we set the flow direction? Is there a tracing tool under network analyst toolset? I can't find it. Which option did you do to get the result? Option 1? Do you have more details? Can you share with me the python script? Since there are many dam points, we have to use loop, right? I just started learning python recently and it's so difficult for me to write script with no bugs....Thank you so much for your help! Maggie ... View more

Hi Bill, I use "trace geometric network" tool and set the dam points as flags, the gage points as barriers, I also disable gage point feature class so that it will stop trace when there is gage point. Then I limit the results to features stopping the trace. The output I get are the layers with selection features. Then I create layers from the selected features for both dam and gage point feature classes. But from the result I don't know which gage point are paired with dam point(nearest along the streamline) and what should I do next so that the nearest ID of gage point can appear in dam point attribution table. Can you please recall which tools you used to realize the task? Is there any record available as my reference? May I write email to you or call you directly if possible? Thank you so much! Maggie ... View more

Yes, I am able to select all of the dams points and gauges points with tracing geometric network tool. Do you mean all the information are contained in the output lines attribution table, including the ID(OID or FID) of dams as well as gauges? The computer I am using now has no ArcMap, I will try later. Can I ask you if I have further questions later? Thank you so much Bill!! ... View more

Thank you so much for your reply Bill! Do you mean to join the line output with the original dam feature class? How can I get the closest downstream gauge id and add it to dam's attribute table? So you've done this to identify the nearest downstream points for many upstream points in one time and we don't need to use python to automate? ... View more

Hi Matt, I have the  exact same task as you had, can you pls share your experience how you accomplished your task? Did the suggestion given by Christine worked? Thank you so much! Maggie ... View more