CMSCOPE changed

1 files changed, 38 insertions, 0 deletions

diff --git a/modules/cacsd/macros/invrs.sci b/modules/cacsd/macros/invrs.sci
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+// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
+// Copyright (C) INRIA -
+//
+// This file must be used under the terms of the CeCILL.
+// This source file is licensed as described in the file COPYING, which
+// you should have received as part of this distribution.  The terms
+// are also available at
+// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt
+
+function Sli=invrs(Sl,alfa);
+    // Sli=invrs(Sl,alfa) computes Sli, the PSSD
+    // inverse of PSSD Sl.
+    //!
+    if typeof(Sl)<>"state-space" then
+        error(msprintf(gettext("%s: Wrong type for input argument #%d: Linear state space expected.\n"),"invrs",1))
+    end
+
+    D=Sl.D;
+    if type(D)==2 then
+        s=poly(0,varn(D));
+        Sl.D=horner(Sl.D,s+alfa);
+    end
+    Sl.A=Sl.A-alfa*eye(Sl.A); //Slnew(s)=Slold(s+alfa)
+
+    [Sreg,Wss]=rowregul(Sl,0,0);
+    if rcond(Sreg.D) >1.d-6 then
+        Sli=invsyslin(Sreg)*Wss;
+    else
+        error(msprintf(gettext("%s: Square but singular system.\n"),"invrs"));
+    end
+    [Q,M]=pbig(Sli.A,0.001,"d");
+    Sli=projsl(Sli,Q,M);//Remove poles at zero.
+
+    if Sli.A~=[] then Sli.A=Sli.A+alfa*eye();end
+    if type(Sli.D)==2 then
+        Sli.D=horner(Sli.D,s-alfa);
+    end
+endfunction