I am attempting to calculate linear mileage of stream data for three predefined fields in model builder. The conceptual approach is to calculate all segments mileage in the first field (total_miles), then calculate a fraction of the records in another field (need_miles), and finally, calculate the percentage of the two in the final field (percentage). I'll use frequency to agregate the segments to their respective HUC 12 areas. The problem I am having, is how to calculate geometry (linear mileage) in model builder? I can't seem to locate the tool that may be dragged to model builder. Thanks so much in advance!!!!
Thanks for you quick reply, although am not certain I'm following your logic precisely. And yes, I am using feature classes. When calculating without model builder, I create the two fields to house mileage (total miles and need miles), use calculate geometry to populate the segmets mileage, and then perform frequency analysis to summarize the values of the HUC 12s. Using model builder, should I be using calculate field prior to utilizing frequency, and what calculation would work for empty fields? Thanks again!
Richard, the field calculation for !SHAPE.LENGTH! / 5280 # does not work. It produces a syntax error when ran on an empty field through field calculation. Any thoughts?