Bug Number: 320
Test netlist: bug_320.cir

Description:
============
This test checks for correct handling of the nonlinear solve parameter
"SEARCHMETHOD".

The default for searchmethod is zero. (which means, essentially, 
no search method).  This circuit will not run without some kind of search
in the nonlinear solver.  This happens to be a PDE(TCAD) device problem.
THe reason for this choice is that PDE problems often require a quadratic 
search method to converge.  Most circuit problems don't seem to require it.

With the old nonlinear solver (.options nonlin nox=0), this happens:

  searchmethod        status
      0               FAIL
      1               FAIL
      2               SUCCESS.
      3               INVALID METHOD - FAIL.

With the new nonlinear solver (.options nonlin nox=1), this happens:

  searchmethod        status
      0               FAIL
      1               FAIL
      2               SUCCESS.
      3               SUCCESS.

With the new solver, nox, searchmethod=2 is a quadratic search (as it also
is for nox=0, the old solver).  When using nox, searchmethod=3 is a 
cubic polynomial search.  Both of searchmethod=2 and 3 are polynomial
searches, and so they tend to behave very similarly.

Anyway, for this test, I have set searchmethod=2.  This should work for both
nox=1 and nox=0.

Verification
============
Run Xyce on the netlist, bug_320.cir.  

Run this with both nox=1 and nox=0.  Both should pass.  Don't bother comparing
output files.  If both nox=1 and nox=0 run successfully, consider this
a passed test.

Special Notes:
==============
THIS TEST SHOULD NOT BE RUN IN PARALLEL.

Additional Notes, by Eric Keiter.  10/12/04.

This test is simply to see if one parameter (searchmethod) is recognized,
and used correctly.  

If searchmethod is used correctly, the circuit will solve, and exit
successfully, and if it is not used correctly, the circuit will fail.

Additional Note, 10/27/04.  Eric Keiter.

If Xyce gives a warning about "FREDLEVEL" being an invalid parameter, this 
is good - this is the correct behavior.

This bug was primarily a parser and/or parameter processing bug.  Xyce was not
processing the "searchmethod" parameter correctly.  It was ignoring it.  Hence
part of the fix involved forcing Xyce to identify which parameters were valid and
which were not.  "FREDLEVEL" is an intentionally incorrect parameter, meant
to test this.



