Nesting two iterators for cost distance calculation in ModelBuilder?

Question

I am attempting to calculate cost distances iteratively for each point element in different datasets.

I created a model that does the job for a single dataset but when I try to batch it I'm getting the following error "ERROR 000865: Input raster or feature source data: I_atlanta_OBJECTID does not exist".

This is, the output layer generated in the "feature select" submodel is not a valid input in the cost distance or in any other process I put after the iterator.

This error occurs only when I nested the model to run it in different datasets and not when I run the model in only one dataset.

Is there any consideration I have to take into account when nesting models?

I have read the documentation available with no luck so far.

Answer 1

The ArcGIS help page for iterators in model builder says that you can only have one iterator per model. (It's the first note, below the table of iterator types.) Perhaps that is why you are having trouble trying to use two in the same model.

I believe if you want to use multiple iterators in modelbuilder you have to build a model for each one and then nest those models inside another one.

Answer 2

There are several ways to solve this issue:

• script a nested loop within a python script
• integrate a submodel into a model with a precondition
• use the batch function of the model inorder to apply it several files (make input and outputfile of the model a parameter, then rightclick on the model > batch)

MGR