Creating a node set with z=0 coordinates in Neper using -nset option

[PengWei97]

Hi neper experts,

I am new to Neper and I am trying to create a node set called "Bottom" containing all nodes in a given mesh file (test.msh) that have a z-coordinate of zero. Because I show the following error during the calculation of moose,

*** ERROR ***
/home/*/polycrystal_2.i:265: (BCs/z_bot/boundary):
    the following node sets (ids) do not exist on the mesh: Bottom (39)

and the original command I created is as follows,

neper -T -n 4
neper -M n4-id1.tess

Can someone please help me with the command line to achieve this? I would greatly appreciate any suggestions or examples.

Thank you in advance for your help!

Best regards,
wei

[rquey]

The bottom node set is called z0 in the default output.