Iteration troubles

Anonymous User

Original User: gjesdahj

Well I got further along in my model and decided to try running it for multiple values just to see if it worked and it didn't - it just ran the first one.  I think it's because there' no arrow from "value" to a process - all of ARC's examples have that as the case. All of the processes that use "value" just use it in %value% form - none of them just have "value" in them.  So for instance, the first thing that isn't the iteration is Select Layer by Attribute and the expression is "FID_1_1" = %value%.  Clearly I can't change the expression to just Value, so I don't know what to do.  Does anyone have any ideas on this? I apologize for not really knowing how iterations work, but it seems like ARC is sort of a learning through doing thing.

Thanks
Jacob

viewshed 2.py.zip

viewshed 4.jpg

curtvprice

Well I got further along in my model and decided to try running it for multiple values just to see if it worked and it didn't - it just ran the first one.  I think it's because there' no arrow from "value" to a process - all of ARC's examples have that as the case.

Jacob, I think you are using the wrong iterator, passing the output of iterate field values into a select by attribute.

What you want to use here is Iterate Field Selection, this will output a layer with a active selection to pipe into your processing chain, each unique value (or combination, if you specify more than one) can then be processed in sequence.

I moved this to a new thread in the Geoprocessing forum...

I apologize for not really knowing how iterations work, but it seems like ARC is sort of a learning through doing thing.

Yes, but that said, there are some very useful free resources at http://training.esri.com -- and the online help chapter on iterators keeps improving (along with the software).