/usr/share/octave/site/m/sundialsTB/cvodes/function_types/CVPrecSolveFn.m is in octave-sundials 2.5.0-3+b1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 | %CVPrecSolveFn - type for user provided preconditioner solve function.
%
% The user-supplied preconditioner solve function PSOLFN
% is to solve a linear system P z = r in which the matrix P is
% one of the preconditioner matrices P1 or P2, depending on the
% type of preconditioning chosen.
%
% The function PSOLFUN must be defined as
% FUNCTION [Z, FLAG] = PSOLFUN(T,Y,FY,R)
% and must return a vector Z containing the solution of Pz=r.
% If PSOLFUN was successful, it must return FLAG=0. For a recoverable
% error (in which case the step will be retried) it must set FLAG to a
% positive value. If an unrecoverable error occurs, it must set FLAG
% to a negative value, in which case the integration will be halted.
% The input argument FY contains the current value of f(t,y).
%
% If a user data structure DATA was specified in CVodeInit, then
% PSOLFUN must be defined as
% FUNCTION [Z, FLAG, NEW_DATA] = PSOLFUN(T,Y,FY,R,DATA)
% If the local modifications to the user data structure are needed in
% other user-provided functions then, besides setting the vector Z and
% the flag FLAG, the PSOLFUN 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).
%
% See also CVPrecSetupFn, CVodeSetOptions
%
% NOTE: PSOLFUN is specified through the property PrecSolveFn to
% CVodeSetOptions and is used only if the property LinearSolver was
% set to 'GMRES', 'BiCGStab', or 'TFQMR' and if the property PrecType
% is not 'None'.
% Radu Serban <radu@llnl.gov>
% Copyright (c) 2005, The Regents of the University of California.
% $Revision: 1.2 $Date: 2011/06/01 20:44:05 $
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