/usr/share/octave/site/m/sundialsTB/kinsol/function_types/KINPrecSolveFn.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 | %KINPrecSolveFn - 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
% the preconditioner matrix (possibly set implicitely by PSETFUN)
%
% The function PSOLFUN must be defined as
% FUNCTION [Z, FLAG] = PSOLFUN(Y, YSCALE, FY, FSCALE, R)
% and must return a vector Z containing the solution of Pz=r.
% The input argument FY contains the current value of f(y), while YSCALE
% and FSCALE are the scaling vectors for solution and system function,
% respectively (as passed to KINSol)
%
% If a user data structure DATA was specified in KINInit, then
% PSOLFUN must be defined as
% FUNCTION [Z, FLAG, NEW_DATA] = PSOLFUN(Y,YSCALE,FY,FSCALE,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).
%
% If successful, PSOLFUN must return FLAG=0. For a recoverable error it
% must set FLAG to a positive value (in which case the solver will attempt
% to correct). If an unrecoverable error occurs, it must set FLAG
% to a negative value, in which case the solver will halt.
%
% See also KINPrecSetupFn, KINSetOptions
%
% NOTE: PSOLFUN is specified through the property PrecSolveFn to KINSetOptions
% and is used only if the property LinearSolver was set to 'GMRES' or 'BiCGStab'.
% Radu Serban <radu@llnl.gov>
% Copyright (c) 2005, The Regents of the University of California.
% $Revision: 1.2 $Date: 2011/06/01 21:01:10 $
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