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xacro arg to xacro:property, or math on xacro args?

asked 2014-01-06 12:56:36 -0500

lucasw

8729 ●137 ●239 ●256 https://github.com/lucasw

updated 2020-11-21 11:36:14 -0500

Should it be possible to set a xacro property with a value passed in as an argument?

<xacro:property name="length" value=$(arg length_arg)" />

Right now I get:

ValueError: could not convert string to float: $(arg chassis_length_arg)

I'd like to be able to do math on xacro arguments, but

${$(arg length_arg) / 2}

also doesn't work so there appears to be no way to do it other than precomputing the right values and passing them in as args.

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answered 2014-01-07 12:15:17 -0500

lucasw

8729 ●137 ●239 ●256 https://github.com/lucasw

It just now occurred to me that the solution is to make a xacro macro wrap all the math on the arguments and the call to the macro reference the arg:

 <xacro:macro name="foo" params="chassis_length" >
     ... do something with ${chassis_length/2}
 <xacro::macro>

 <xacro:foo chassis_length="$(arg chassis_length)">

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Asked: 2014-01-06 12:56:36 -0500

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Last updated: Jan 07 '14

xacro arg to xacro:property, or math on xacro args? edit

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xacro arg to xacro:property, or math on xacro args?