Wed Nov 5 02:13:59 EST 2014

Changing variables

G V = I

Suppose for a circuit we're not just using current inputs, but a
couple of the nodes will have set voltages, how to change variables?

In SPICE this is done using Norton equivalent transformation.

It should be straightforward to make this change of variables, but
what about the resulting matrix?  How to express that transformation?
Is the matrix still pos def?