Obtain a vector of radius

Submitted by mouse19529 on Fri, 03/16/2018 - 16:37

Hi all,

I want to obtain a vector or array of particle radius.
I use the following commends:

compute rad all property/atom radius
variable ra atom c_rad
variable rb equal ra[1]
if "${rb} >= 0." then "run 1"

But it does not work.

Who can tell me how to use per-atom vectors?

Thank you very much.

Hao XIONG