%CVJacTimesVecFn - type for user provided Jacobian times vector function.
%
%   The function JTVFUN must be defined as 
%        FUNCTION [JV, FLAG] = JTVFUN(T,Y,FY,V)
%   and must return a vector JV corresponding to the product of the 
%   Jacobian of f(t,y) with the vector v.
%   The input argument FY contains the current value of f(t,y).
%   If a user data structure DATA was specified in CVodeMalloc, then
%   JTVFUN must be defined as
%        FUNCTION [JV, FLAG, NEW_DATA] = JTVFUN(T,Y,FY,V,DATA)
%   If the local modifications to the user data structure are needed in
%   other user-provided functions then, besides setting the vector JV,
%   the JTVFUN function must also set NEW_DATA. Otherwise, it should set
%   NEW_DATA=[] (do not set NEW_DATA = DATA as it would lead to
%   unnecessary copying).
%
%   The function JTVFUN must set FLAG=0 if successful, or FLAG~=0 if
%   a failure occurred.
%
%   See also CVodeSetOptions
%
%   NOTE: JTVFUN is specified through the property JacobianFn to
%   CVodeSetOptions and is used only if the property LinearSolver
%   was set to 'GMRES', 'BiCGStab', or 'TFQMR'.

% Radu Serban <radu@llnl.gov>
% Copyright (c) 2005, The Regents of the University of California.
% $Revision: 1.1 $Date: 2007/05/11 18:51:33 $
