Re: ss error

[Doug Stewart]

On Sun, Nov 21, 2010 at 11:46 AM, address@hidden
<address@hidden> wrote:
>
> Hi!
>
> I'm an octave new user so I don't understand a message from compiler:
>
> octave:2> A=[0 1 0 0;-1000 -980 1000 980;0 0 0 1;28.57 28 -28.57 -28]
> A =
>
>   0.0000e+00   1.0000e+00   0.0000e+00   0.0000e+00
>  -1.0000e+03  -9.8000e+02   1.0000e+03   9.8000e+02
>   0.0000e+00   0.0000e+00   0.0000e+00   1.0000e+00
>   2.8570e+01   2.8000e+01  -2.8570e+01  -2.8000e+01
>
> octave:3> B=[0 50000 0 0]
> B =
>
>       0   50000       0       0
>
> octave:4> C=[0 0 1 0]
> C =
>
>   0   0   1   0
>
> octave:5> J=0
> J = 0
> octave:6> sys=ss(A,B,C,J)
> warning: abcddim: a(4x4) and b(1x4) are not compatible
> error: a(4x4), b(1x4), c(1x4), d(1x1); incompatible
> error: called from:
> error:   /usr/share/octave/packages/3.2/control-1.0.11/ss.m at line 210,
> column 5
>
> I believe an dimension error in my 4x4 system. Is that? there is another
> function to solve 4x4 state variable form?
>
> thank
>
>
>

Try:

 sys=ss(A,B',C',J)

this will change B and C to column vectors from row vectors