topic Re: Iterate tool with multiple input variables in Geoprocessing Questions

Iterate tool with multiple input variables

JasonAdelaars — Thu, 12 Jul 2012 21:19:23 GMT

Hey forum,

I've created a raster calculator model that includes two input variables and produces a single output raster. Now i want to quickly do that calculation over all 90 variable pairs times 8 folders. Model builder only lets me have one iterator.

For simplicity sake:

Let say the calculation is: RasterA + RasterB = RasterC;

now I want to do that calculation for 90 paired (RasterA and RasterB) variables within a folder. I am unfamiliar with python, but I have the time and resources to learn it. Any ideas??

Thanks,
Jason

Re: Iterate tool with multiple input variables

SolomonPulapkura — Thu, 12 Jul 2012 23:56:45 GMT

If RasterA and RasterB are in the same folder, you will need to somehow distinguish the 2 in your code logic so that they can be passed as A and B parameters respectively.
Otherwise whats is variable A for one loop might be variable B for another loop. Hope this makes sense?

Re: Iterate tool with multiple input variables

JasonAdelaars — Mon, 16 Jul 2012 14:05:51 GMT

They are distinguishable. Each pair needs to be input into the model for each iteration. To my understanding right now the iterator does not allow multiple inputs into a model.

Re: Iterate tool with multiple input variables

JonathanQuinn — Mon, 16 Jul 2012 16:34:32 GMT

You can create two separate iterators that exist in their own models. Then, add both models to a "final" model, and set preconditions so the iterators need to run to collect the values of the iterators before the final processes run in your full model. Take a look at this resource here for guidance.

Re: Iterate tool with multiple input variables

JasonAdelaars — Mon, 16 Jul 2012 17:40:26 GMT

Thanks Jonathan, i think this is on the right track. But the iterator models pass over all the files in the folder and only runs the last two rasters through the final model.

I need it to take a pair of rasters, run them through the model, and produce an output. Then take the next pair of rasters, run through model, produce output...etc.

Jason