When I use the periodic boundary, whether the packing to be generated should be periodic

Hello,

please read [1] and provide more information.
The answer is "it depends on your specific case". But we have no information about your specific case, so we cannot help without more information :-)

Cheers
Jan

[1] https://www.yade-dem.org/wiki/Howtoask

Jan, thanks a lot for your response.
 I mean that the packings are all periodically generated by setting the parameter periodic of function makeCloud to be True in the examples Periodic simple shear[1] and Periodic triaxial test[2]. Does this mean that the packing of the period boundary must be periodically generated?
 The relevant code is as follows:
O.periodic=True
sp=pack.SpherePack()
if 0:
 ## uniform distribution
 sp.makeCloud((0,0,0),(2,2,2),rMean=.1,rRelFuzz=.3,periodic=True)
else:
 ## create packing from clumps
 # configuration of one clump
 c1=pack.SpherePack([((0,0,0),.03333),((.03,0,0),.017),((0,.03,0),.017)])
 # make cloud using the configuration c1 (there could c2, c3, ...; selection between them would be random)
 sp.makeClumpCloud((0,0,0),(2,2,2),[c1],periodic=True,num=500)
[1]https://yade-dem.org/doc/tutorial-examples.html#periodic-triaxial-test
[2]https://gitlab.com/yade-dev/trunk/blob/master/doc/sphinx/tutorial/06-periodic-triaxial-test.py

Hello,

> Does this mean that the packing of the period boundary must be periodically generated?

Instant replay:
The answer is "it depends on your specific case".
It can be "yes" or "no" or "maybe" or "rather yes", or ...
depending on the specific case, whose description is needed to get more relevant answer [1].

> ... the packings are all periodically generated ...
> ... in the examples Periodic simple shear and Periodic triaxial test ...
> Does this mean that ... must be ...?

No, that something is present in examples does not necessarily imply that it must be like that at all circumstances.
It depends on your specific case :-)

Cheers
Jan

[1] https://www.yade-dem.org/wiki/Howtoask

Thanks, Jan Stránský, that solved my question.