topic How to use Set Null in Model Builder? in ModelBuilder Questions

How to use Set Null in Model Builder?

AndrewMartin8 — Fri, 11 Aug 2017 16:30:39 GMT

I am trying to emulate the raster calculator that takes a flow accumulation raster and turns it into a stream raster. Where the number "849840" is the threshold value.

How would I use the Set Null tool in the model builder that will give me the same results?

What would I put in the fields?

Re: How to use Set Null in Model Builder?

ChrisDonohue__GISP — Fri, 11 Aug 2017 16:46:00 GMT

If I remember correctly, SetNull (Spatial Analyst) would be done like this to complete your task:

The Input Conditional Raster: dem_fa . (your source raster to operate on)

Expression (optional) would be: VALUE > 849840 . (values above 849840 are evaluated by the tool as True, so will become Null)

Input File raster or constant value: 1 . (constant value to set if False/Not Null, ie your streams will have a value of 1)

Output raster: (your output file name goes here)

Note: be sure to set the Environments (button at bottom of tool). Also, I would avoid using the Default Geodatabase (Default.gdb) and instead set up a geodatabase specifically for this data and its processing.

Chris Donohue, GISP

Re: How to use Set Null in Model Builder?

curtvprice — Fri, 11 Aug 2017 22:08:30 GMT

Alternatively, you can add the Raster Calculator tool in Model Builder and use it the same way you used it interactively.