On 22.02.2011, at 05:59, Thomas D. Dean wrote:
> Octave 3.4.0, control 2.0.0
>> From the Converting from S to Z domain thread,
>
> octave:1> num = [1 0];den = [1 0 4];
> octave:2> sys = tf(num, den,1);sysz=c2d(sys,1);sysout(sysz,'tf')
> error: tf: c2d: not implemented yet
> error: called from:
> error: /home/tomdean/octave/control-2.0.0/@tf/__c2d__.m at line 31,
> column 7
> error: /home/tomdean/octave/control-2.0.0/@lti/c2d.m at line 46,
> column 7
>
> Looks like __c2d__ is a stub that only displays error messages, either
> "not implemented" or "invalid method".
>
> # cat /home/tomdean/octave/control-2.0.0/@tf/__c2d__.m
> ...<snip>
> function sys = __c2d__ (sys, tsam, method = "zoh")
>
> [p, m] = size (sys);
>
> switch (method)
> case {"zoh", "std"}
> error ("tf: c2d: not implemented yet");
>
> otherwise
> error ("tf: c2d: %s is an invalid method", method);
>
> endswitch
>
> endfunction
>
> tomdean
Yes, @tf/__c2d__.m is only a stub right now. address@hidden/__c2d__.m offers zero-order hold only. There is a list of missing features in the PROJECTS file: