On 06.07.2011, at 20:41, Juan Pablo Carbajal wrote: > On Wed, Jul 6, 2011 at 8:29 PM, Lukas Reichlin <[email protected]> > wrote: >> On 06.07.2011, at 14:54, Juan Pablo Carbajal wrote: >> >>> Hi Lukas, >>> I was following your example of a wrapper and found the following >>> the function ss2tf has a different interface than your function ss. >>> The last argument is not the time sample as in your function but an >>> index of the input vector >>> http://www.mathworks.com/help/toolbox/signal/ss2tf.html >>> >>> Is there any of the options in your ss function that can handle this >>> or should that option be added? >>> >>> Also, I cannot access tfdata directly nor octave can find it (though >>> is there in @lti), I am not experienced with objects and may be >>> something related to that. >> >> Matlab's Signal Toolbox looks like a dump for old Control System Toolbox >> commands ;-) >> >> Systems are handled like matrices: >> >> matrix(row_indices, column_indices) >> system(output_indices, input_indices) >> >> To select only certain inputs: >> sys(:, idx) >> >> Regards >> Lukas >> >> >> >> > > Lukas, thanks for the answer > > If one is searching for the transfer function for the iu-th input it > is needed to be able to access the matrices in the state space > representation, not only inputs and outputs. Therefore I do not think > sys(:,idx) > would help. > In the old package (1995, this is not even the legacy you passed me) > ss2tf has a loop over k (the number of outputs) and calculates the > numerator of the TF as > num(k,:) = poly(a - b(:,iu)*c(k,:)) - poly(a) + d(k,iu)*den; > where a,b,c,d are the system SS matrices. > > I think this should be added to your example right? or you see a workaround? > > Cheers, > > JPi
Are you looking for something like this? sys.b(:,iu) sys.c(k,:) Regards, Lukas ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2d-c2 _______________________________________________ Octave-dev mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/octave-dev
