mess_wrap_mechss.m

function [eqn, opts, oper] = mess_wrap_mechss(sys, opts, usfs)
%% function [eqn, opts, oper] = mess_wrap_mechss(sys, opts, usfs)
%
% Input
%   sys        mechss(M,C,K,B,F,G,D) a continuous-time first-order sparse
%              state-space model object of the following form:
%              M*x''(t) C*x'(t) + K*x(t) = B*u(t)
%                                   y(t) = F*x(t) + G*x'(t) + D*u(t)
%
%   opts       transit argument required by logger functions
%
%   usfs       string: name of folder containing the function handle set
%              (optional, defaults to 'so_1')
%
% Output
%   eqn        struct contains data for equations
%              M*x"(t) + E x'(t) + K*x(t)= B2*u(t)
%                                    y(t)= Cp*x(t) + Cv*x'(t) + D*u(t)
%
%              eqn.M_ = M
%              eqn.E_ = C
%              eqn.K_ = K
%              eqn.C  = |Cp Cv|
%              eqn.D  = D
%
%              for usfs = 'so_1':
%                      | 0  |
%              eqn.B = | B2 |
%
%              for usfs = 'so_2':
%                      | B2 |
%              eqn.B = | 0  |
%
%   opts       transit argument required by logger functions
%
%   oper       struct contains function handles for operation with A and E
%
%

%
% This file is part of the M-M.E.S.S. project
% (http://www.mpi-magdeburg.mpg.de/projects/mess).
% Copyright (c) 2009-2023 Jens Saak, Martin Koehler, Peter Benner and others.
% All rights reserved.
% License: BSD 2-Clause License (see COPYING)
%

%%
narginchk(2, 3);

%% set oper
if nargin < 3 || isempty(usfs)
    [oper, opts] = operatormanager(opts, 'so_1');  % default setting
else
    [oper, opts] = operatormanager(opts, usfs);
end

%% set eqn
eqn.sys = sys;

if not(isempty(find(eqn.sys.M, 1)))
    eqn.M_ = eqn.sys.M;
end

if not(isempty(find(eqn.sys.C, 1)))
    eqn.E_ = eqn.sys.C;
end
if not(isempty(find(eqn.sys.K, 1)))
    eqn.K_ = eqn.sys.K;
end
if not(isempty(find(eqn.sys.B, 1)))
    switch usfs
        case 'so_1'
            eqn.B = [zeros(size(eqn.sys.B)); full(eqn.sys.B)];
        case  'so_2'
            eqn.B = [full(eqn.sys.B); zeros(size(eqn.sys.B))];
        otherwise
            mess_warn(opts, 'warning_arguments', ...
                      ['eqn.B is only set for function handles ', ...
                       '''so1'' and ''so2''']);
    end
end

if not(isempty(eqn.sys.F)) && not(isempty(eqn.sys.G))
    eqn.C = [full(eqn.sys.F), full(eqn.sys.G)];
elseif not(isempty(eqn.sys.F)) && isempty(eqn.sys.G)
    eqn.C = [full(eqn.sys.F), zeros(size(eqn.sys.F))];
elseif isempty(eqn.sys.F) && not(isempty(eqn.sys.G))
    eqn.C = [zeros(size(eqn.sys.G)), full(eqn.sys.G)];
else
    mess_warn(opts, 'warning_arguments', ...
              'Neither Cp nor Cv is given. eqn.C will be missing');
end

if not(isempty(find(eqn.sys.D, 1)))
    eqn.D = eqn.sys.D;
end

eqn.haveE = true;