How to perform port cropping?

[Asachoo]

How to perform port cropping?

[Asachoo]

Will this help ? I think there is already a built-in function for your request.

https://scikit-rf.readthedocs.io/en/latest/api/generated/skrf.network.Network.subnetwork.html#skrf.network.Network.subnetwork

Also, should this be in the Discussion thread rather than Issues ? 🤔 We can always convert Discussions to Issues once it is confirmed

scikit-rf/skrf/network.py

Lines 5442 to 5480 in b32ff9c

	def subnetwork(ntwk: Network, ports: int, offby:int = 1) -> Network:
	"""
	Return a subnetwork of a given Network from a list of port numbers.
	A subnetwork is Network which S-parameters corresponds to selected ports,
	with all non-selected ports considered matched.
	The resulting subNetwork is given a new Network.name property
	from the initial name and adding the kept ports indices
	(ex: 'device' -> 'device13'). Such name should make easier the use
	of functions such as n_twoports_2_nport.
	Parameters
	----------
	ntwk : :class:`Network` object
	Network to split into a subnetwork
	ports : list of int
	List of ports to keep in the resultant Network.
	Indices are the Python indices (starts at 0)
	offby : int
	starting value for s-parameters indexes in the sub-Network name parameter.
	A value of `1`, assumes that a s21 = ntwk.s[:,1,0]. Default is 1.
	Returns
	-------
	subntwk : :class:`Network` object
	Resulting subnetwork from the given ports
	See also
	--------
	Network.subnetwork, n_twoports_2_nport
	Examples
	--------
	>>> tee = rf.data.tee # 3 port Network
	>>> tee12 = rf.subnetwork(tee, [0, 1]) # 2 port Network from ports 1 & 2, port 3 matched
	>>> tee23 = rf.subnetwork(tee, [1, 2]) # 2 port Network from ports 2 & 3, port 1 matched
	>>> tee13 = rf.subnetwork(tee, [0, 2]) # 2 port Network from ports 1 & 3, port 2 matched

Thanks for your tip, your reply solved my problem very well

[Asachoo]

An ugly attempt to achieve this

def renumbered(self, from_ports: Sequence[int], to_ports: Sequence[int] = None) -> 'Network':
    """
    Return a renumbered Network, leave self alone.

    Parameters
    ----------
    from_ports : list-like
        List of port indices to change. Size between 1 and N_ports.
    to_ports : can be None or list-like
        List of desired port indices. Size between 1 and N_ports.
        None to use automatically generate a List of desired port indices. Size is between 1 and from_ports' size.

    NB: from_ports and to_ports must have same size.

    Returns
    -------
    ntwk : :class:`Network` object
        Resulting renumbered Network

    See Also
    --------
    renumber
    flip
    flipped

    """
    out = self.copy()
    if to_ports:
        out.renumber(from_ports, to_ports)
    else:
        to_ports_idx = npy.ix_(npy.arange(out.s.shape[0], from_ports, from_ports)
        out.s = out.s[to_ports_idx]
        out.z0 = out.z0[:, from_ports]
    return out
        

[denzchoe]

Will this help ? I think there is already a built-in function for your request.

https://scikit-rf.readthedocs.io/en/latest/api/generated/skrf.network.subnetwork.html#skrf.network.subnetwork

Also, should this be in the Discussion thread rather than Issues ? 🤔
We can always convert Discussions to Issues once it is confirmed

scikit-rf/skrf/network.py

Lines 5442 to 5480 in b32ff9c

	def subnetwork(ntwk: Network, ports: int, offby:int = 1) -> Network:
	"""
	Return a subnetwork of a given Network from a list of port numbers.
	A subnetwork is Network which S-parameters corresponds to selected ports,
	with all non-selected ports considered matched.
	The resulting subNetwork is given a new Network.name property
	from the initial name and adding the kept ports indices
	(ex: 'device' -> 'device13'). Such name should make easier the use
	of functions such as n_twoports_2_nport.
	Parameters
	----------
	ntwk : :class:`Network` object
	Network to split into a subnetwork
	ports : list of int
	List of ports to keep in the resultant Network.
	Indices are the Python indices (starts at 0)
	offby : int
	starting value for s-parameters indexes in the sub-Network name parameter.
	A value of `1`, assumes that a s21 = ntwk.s[:,1,0]. Default is 1.
	Returns
	-------
	subntwk : :class:`Network` object
	Resulting subnetwork from the given ports
	See also
	--------
	Network.subnetwork, n_twoports_2_nport
	Examples
	--------
	>>> tee = rf.data.tee # 3 port Network
	>>> tee12 = rf.subnetwork(tee, [0, 1]) # 2 port Network from ports 1 & 2, port 3 matched
	>>> tee23 = rf.subnetwork(tee, [1, 2]) # 2 port Network from ports 2 & 3, port 1 matched
	>>> tee13 = rf.subnetwork(tee, [0, 2]) # 2 port Network from ports 1 & 3, port 2 matched