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Diffstat (limited to 'modules/cacsd/macros/findAC.sci')
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diff --git a/modules/cacsd/macros/findAC.sci b/modules/cacsd/macros/findAC.sci new file mode 100755 index 000000000..bdda5148b --- /dev/null +++ b/modules/cacsd/macros/findAC.sci @@ -0,0 +1,77 @@ +function [A,C,rcnd]=findAC(s,n,l,R,meth,tol,printw) + A=[];C=[];rcnd=[]; + [nargout,nargin] = argn(0) + //FINDAC Finds the system matrices A and C of a discrete-time system, given the + // system order and the relevant part of the R factor of the concatenated + // block-Hankel matrices, using subspace identification techniques (MOESP + // or N4SID). + // + // [A,C] = FINDAC(S,N,L,R,METH,TOL,PRINTW) computes the system matrices + // A and C. The model structure is: + // + // x(k+1) = Ax(k) + Bu(k) + Ke(k), k >= 1, + // y(k) = Cx(k) + Du(k) + e(k), + // + // where x(k) and y(k) are vectors of length N and L, respectively. + // + // [A,C,RCND] = FINDAC(S,N,L,R,METH,TOL,PRINTW) also returns the vector + // RCND of length 4 containing the condition numbers of the matrices + // involved in rank decisions. + // + // S is the number of block rows in the block-Hankel matrices. + // + // METH is an option for the method to use: + // METH = 1 : MOESP method with past inputs and outputs; + // = 2 : N4SID method. + // Default: METH = 1. + // Matrix R, computed by FINDR, should be determined with suitable arguments + // METH and JOBD. + // + // TOL is the tolerance used for estimating the rank of matrices. + // If TOL > 0, then the given value of TOL is used as a lower bound + // for the reciprocal condition number. + // Default: prod(size(matrix))*epsilon_machine where epsilon_machine + // is the relative machine precision. + // + // PRINTW is a select for printing the warning messages. + // PRINTW = 1: print warning messages; + // = 0: do not print warning messages. + // Default: PRINTW = 0. + // + // See also FINDABCD, FINDBD, FINDBDK, FINDR, ORDER, SIDENT + // + + // V. Sima 18-01-2000. + // + // Revisions: + // + + nin = nargin; + nout = nargout; + // + if nin<7 then + printw = 0; + end + if nin<6 then tol = 0;end + if tol==[] then tol = 0;end + if nin<5 then meth = 1;end + if meth==[] then meth = 1;end + if nin<4 then + error(msprintf(gettext("%s: Wrong number of input arguments: %d to %d expected.\n"),"findAC",4,7)); + end + // + // Compute system matrices A and C. + job = 2; + nsmpl = 0; + if nout==1 then + A = sident(meth,job,s,n,l,R,tol,nsmpl,[],[],printw); + elseif nout==2 then + [A,C] = sident(meth,job,s,n,l,R,tol,nsmpl,[],[],printw); + elseif nout==3 then + [A,C,rcnd] = sident(meth,job,s,n,l,R,tol,nsmpl,[],[],printw); + else + error(msprintf(gettext("%s: Wrong number of output arguments: %d to %d expected.\n"),"findAC",1,3)); + end + // + // end findAC +endfunction |