How to get max value from 3 vector files?

Question

I'd like to know how to the get max value from 3 vector files. Originally, the vector file are interpolated images. (First, point data are interpolated into surface data by IDW method and then exported into vector file). Now I need a vector file with max value obtained from the 3 vector files. When I work on raster image to get max value, firstly, I always do layer stack operation on all images from which max value will extract. After that, I get max value image from stacked image. So what I want to ask is do I need to do layer stack on 3 vector images? If so, what is the operation name/tool in ArcGIS and how can I find max value from stacked vector files?

Answer 1

You don't need to do a layer stack first. Just use the Cell Statistics tool on your rasters:

OutRas = CellStatistics([InRas1, InRas2, InRas3], "MAXIMUM", "DATA")

EDIT: If you want to find the maximum when your inputs are vectors you can do a spatial join and set the merge rule of the field mapping to "MAX".

Answer 2

I agree with Sylvester that you could stick with the raster analysis approach until you get the max value, If you want to have classes you can use a reclass in each raster before the cell Statistics.

But you really need\want to go vector, this is how I would do it:

• Use a union to break all polygons between the 3 Layers (If you have only have access to arcview, you might need to do it in two steps, union two layers, and then, union the result to the third one). Maybe this is what you call stack?
• Create a new attribute\field;
• Use field calculator to populate the new attribute using values from the attributes of the initial layers inside a max function whether from vb or python.

This is the 9.3 approach, but I believe it won't be much different in 10.1