Solving a Riccati equation via Schur decomposition in the versions later than MATLAB 7.0

Hi, I was using ric_schr (Mu Analysis and Synthesis Toolbox) command in MATLAB 7.0 to solve riccati equation via schur decomposition. However, this command (as well as the toolbox) is missing in later versions of MATLAB such as MATLAB 7.6.0 (R2008a). Is there any other substitute for ric_schr in the subsequent versions?

Answer 1

[Walter Roberson]

I find evidence that ric_schr become part of the Robust Control Toolbox, but the function of that name does seem to have disappeared.

Possibly the current replacement function would be http://www.mathworks.com/help/toolbox/robust/ref/bstmr.html

See also this contributed code which seems to use schur() and ordschur() for this purpose.

[N Madani SYED]

Thanks for the reply. I'll see how well the information works out for me.

Answer 2

[burak ergocmen]

I think ordschur is not working on script . Is there a way or another code for that

[Christine Tobler]

Could you post the error message you are receiving when calling ordschur? I don't see a reason why it wouldn't work in a script.

[burak ergocmen]

I use it in the simulink/matlab function. schur is working well but if we type ordschur , it is not working and there is error message .

Undefined function or variable 'ordschur'.

Function 'shurrmethod ' (#44.186.213), line 13, column 1: "[U,S]=ordschur(Ud,Sd,'lhp')" Launch diagnostic report.