topic Set Default GPLinearUnit to Input Units in Python Questions

Set Default GPLinearUnit to Input Units

AndrewFulton — Mon, 28 Jul 2014 18:52:09 GMT

How would I go about setting the default GPLinearUnit parameter's units to the same as an input, or even a default value of 'meters', within a Python toolbox? I assume it happens in update Parameters, but don't know how to approach this issue.

Your help will be greatly appreciated

### From what I've been able to figure out, there is no way to choose a default linear unit such as 'meters'; however, the linear unit in the tool dialog will correspond with the active Data Frame's Map Units. I think this only works in ArcMap. At least there is an ArcCatalog Window in ArcMap now

Message was edited by: Andrew Fulton

Re: Set Default GPLinearUnit to Input Units

JustinBousquin — Wed, 01 Apr 2015 20:39:56 GMT

I've been trying to figure this out as well. I've somewhat been able to get it working using updateParameters, the trick is matching its required format and units.

#For a default meters (where param[1] is your parameter with datatype GPLinearUnit)

def updateParameters(self, params):

if not params[1].altered:

params[1].values = "0 Meters"

#Updating based on an input layer (params[0]) is trickier because spatialReference.linerarUnitName doesn't match up with the GPLinearUnit types

def updateParameters(self, params):

if not params[1].altered and params[0].altered:

spRef=arcpy.Describe(params[0].valueAsText).spatialReference

params[2].values = spRef.linearUnitName

if spRef.linearUnitName == "Foot_US":

params[1].values = "0 Feet"

I'll let you know if I come across a better solution

Re: Set Default GPLinearUnit to Input Units

JustinBousquin — Thu, 02 Apr 2015 17:09:50 GMT

To update a GPLinearUnit parameter (units) based on an input parameter (input) use parameterDependencies in getParameterInfo:

units.parameterDependencies = [input.name]