Hi All, When thinking about sparse matrix representation for S/Y/Z parameters, shouldn't we consider more possible cases than just interconnects? Some cases of importance involving sparse/redundant matrices are NOT interconnects. For example, here is PDN (power distribution network) with two pairs of power ports, Z-parameters (4x4 matrix): Z = [ V1 V1 V2 V2 V1 V1 V2 V2 V2 V2 V3 V3 V2 V2 V3 V3 ]; Possible simple description: [ports 4] [VECTOR 3] 1 : (1,1) (1,2) (2,1) (2,2) 2 : (1,3) (1,4) (2,3) (2,4) (3,1) (3,2) (4,1) (4,2) 3 : (3,3) (3,4) (4,3) (4,4) [begin data] freq1 real(V1) imag(V1) real(V2) imag(V2) real(V3) imag(V3) freq2 real(V1) imag(V1) real(V2) imag(V2) real(V3) imag(V3) .... Note that using "vector" is a universal way to define smaller # of components, suitable for all types of topologies, because it does not imply any topological assumptions. Vladimir ------------------------------------------------------------------ The IBIS Ad Hoc Interconnect Task Group Mailing List Archives are available at: //www.freelists.org/archives/ibis-interconn TO UNSUBSCRIBE: Send a message to "ibis-interconn-request@xxxxxxxxxxxxx" with a subject of "unsubscribe" To administer your subscription status from the web, visit: //www.freelists.org/list/ibis-interconn