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Diffstat (limited to 'modules/cacsd/macros/findx0BD.sci')
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diff --git a/modules/cacsd/macros/findx0BD.sci b/modules/cacsd/macros/findx0BD.sci new file mode 100755 index 000000000..2554038f2 --- /dev/null +++ b/modules/cacsd/macros/findx0BD.sci @@ -0,0 +1,120 @@ +function [x0,B,D,V,rcnd]=findx0BD(A,C,y,u,withx0,withd,tol,printw) + x0=[];B=[];D=[];V=[];rcnd=[]; + [nargout,nargin] = argn(0) + //FINDX0BD Estimates the initial state and/or the matrices B and D of a + // discrete-time linear system, given the (estimated) system + // matrices A, C, and a set of input/output data. + // + // [X0,B,D] = FINDX0BD(A,C,Y,U,WITHX0,WITHD,TOL,PRINTW) estimates the + // initial state X0 and the matrices B and D of a discrete-time + // system using the system matrices A, C, output data Y and the input + // data U. The model structure is : + // + // x(k+1) = Ax(k) + Bu(k), k >= 1, + // y(k) = Cx(k) + Du(k), + // + // The vectors y(k) and u(k) are transposes of the k-th rows of Y and U, + // respectively. + // + // WITHX0 is a select for estimating the initial state x0. + // WITHX0 = 1: estimate x0; + // = 0: do not estimate x0. + // Default: WITHX0 = 1. + // + // WITHD is a select for estimating the matrix D. + // WITHD = 1: estimate the matrix D; + // = 0: do not estimate the matrix D. + // Default: WITHD = 1. + // + // 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. + // + // [x0,B,D,V,rcnd] = FINDX0BD(A,C,Y,U) also returns the orthogonal + // matrix V which reduces the system state matrix A to a real Schur + // form, as well as some estimates of the reciprocal condition numbers + // of the matrices involved in rank decisions. + // + // B = FINDX0BD(A,C,Y,U,0,0) returns B only, and + // [B,D] = FINDX0BD(A,C,Y,U,0) returns B and D only. + // + // See also FINDBD, INISTATE + // + + // V. Sima 13-05-2000. + // + // For efficiency, most errors are checked in the mexfile findBD. + // + // Revisions: + // V. Sima, July 2000. + // + ni = nargin; + nout = nargout; + if ni<4 then + error(msprintf(gettext("%s: Wrong number of input arguments: %d to %d expected.\n"),"findx0BD",4,8)); + end + if nout<1 then + error(msprintf(gettext("%s: Wrong number of output arguments: At least %d expected.\n"),"findx0BD",1)); + end + // + if ni<8 then + printw = 0; + end + if ni<7 then tol = 0;end + if tol==[] then tol = 0;end + if ni<6 then + withd = 1; + elseif withd ==[] then + withd = 1; + elseif (withd~=0)&(withd~=1) then + warning(msprintf(gettext("%s: Wrong value for input argument #%d: %d or %d expected.\n"),"findx0BD",6,0,1)) + end + if ni<5 then withx0 = 1;end + if withx0 ==[] then withx0 = 1;end + job = withd+1; + // + if withx0==1 then + if withd==1 then + [x0,B,D,Vl,rcndl] = findBD(withx0,1,job,A,C,y,u,tol,printw); + if nout>3 then + V = Vl; + end + if nout>4 then + rcnd = rcndl; + end + else + [x0,B,Vl,rcndl] = findBD(withx0,1,job,A,C,y,u,tol,printw); + if nout>2 then + D = Vl; + end + if nout>3 then + V = rcndl; + end + end + else + // Below, x0 means B, and B means D or V ! + if withd==1 then + [x0,B,Vl,rcndl] = findBD(withx0,1,job,A,C,y,u,tol,printw); + if nout>2 then + D = Vl; + end + if nout>3 then + V = rcndl; + end + else + [x0,B,Vl] = findBD(withx0,1,job,A,C,y,u,tol,printw); + if nout>2 then + D = Vl; + end + end + end + // + // end findx0BD +endfunction |