Index: mttroot/mtt/bin/trans/m/mtt_implicit.m
==================================================================
--- mttroot/mtt/bin/trans/m/mtt_implicit.m
+++ mttroot/mtt/bin/trans/m/mtt_implicit.m
@@ -3,13 +3,18 @@
 ## ###############################################################
 ## ## Version control history
 ## ###############################################################
 ## ## $Id$
 ## ## $Log$
+## ## Revision 1.1  1999/04/02 06:23:20  peterg
+## ## Initial revision
+## ##
 ## ###############################################################
 
 ## Copyright (C) 1999 by P.J. Gawthrop
 
+  I_open = nozeros(open.*[1:Nx]'); # Indices of open switches
+  x(I_open) = 0.0;		# Open switches have zero state
   I = nozeros(!open.*[1:Nx]');	# Indices of states to update
-  x(I) = AA(I,I)\(AAx(I) + dx(I)*dt);	# Implicit update (exept open switches);
+  x(I) = AA(I,I)\(AAx(I) + dx(I)*dt);	# Implicit update (except open switches);
 
 endfunction