sys2tf seems broken in 2.1.38

[Nicholas Piper]

I'm using Octave 2.1.38 that I compiled myself, with gcc version
2.95.3 20010315 (release).

I first noticed that the DEMOcontrol didn't work correctly, but now I
also see that sys2tf fails with a traceback.

If I select [ 1] Double integrator example from the DEMOcontrol I get:

....
Press a key to execute command  executing
Input(s)
      1: u_1

Output(s):
     1: y_1

state-space form:
2 continuous states, 0 discrete states
State(s):
    1: x_1
    2: x_2

A matrix: 2 x 2
  0  1
  0  0
B matrix: 2 x 1
  0
  1
C matrix: 1 x 2
  1  0
D matrix: 1 x 1
0
---
 
Notice that the Octave controls  toolbox automatically
assigns names to the states, inputs and outputs,
and that the D matrix was filled in automatically.
We verify that it's a double integrator via sysout:
Command: sysout(sys,"tf")
Press a key to execute command  executing
Input(s)
      1: u_1

Output(s):
     1: y_1

error: A(I) = X: X must be a scalar or a vector with same length as I
error: assignment failed, or no method for `matrix = matrix'
error: evaluating assignment expression near line 64, column 11
error: evaluating for command near line 45, column 3
error: called from `zginit' in file 
`/usr/local/share/octave/2.1.38/m/control/util/zginit.m'
error: evaluating assignment expression near line 59, column 6
error: called from `__zgpbal__' in file 
`/usr/local/share/octave/2.1.38/m/control/util/__zgpbal__.m'
error: evaluating assignment expression near line 81, column 8
error: called from `tzero' in file 
`/usr/local/share/octave/2.1.38/m/control/base/tzero.m'
error: evaluating if command near line 57, column 3
error: called from `ss2tf' in file 
`/usr/local/share/octave/2.1.38/m/control/system/ss2tf.m'
error: evaluating if command near line 77, column 5
error: evaluating if command near line 72, column 3
error: called from `sysupdate' in file 
`/usr/local/share/octave/2.1.38/m/control/system/sysupdate.m'
error: evaluating assignment expression near line 95, column 9
error: evaluating if command near line 94, column 3
error: called from `sysout' in file 
`/usr/local/share/octave/2.1.38/m/control/system/sysout.m'
error: near line 28 of file 
`/usr/local/share/octave/2.1.38/m/control/util/run_cmd.m'
error: evaluating if command near line 133, column 13
error: evaluating while command near line 125, column 11
error: evaluating if command near line 113, column 9
error: evaluating while command near line 106, column 7
error: evaluating if command near line 54, column 5
error: evaluating while command near line 44, column 3
error: called from `sysrepdemo' in file 
`/usr/local/share/octave/2.1.38/m/control/system/sysrepdemo.m'
error: evaluating switch command near line 69, column 5
error: evaluating while command near line 51, column 3
error: called from `DEMOcontrol' in file 
`/usr/local/share/octave/2.1.38/m/control/base/DEMOcontrol.m'
octave:1> 






Also sys2tf fails:

octave:118> sys
sys =
{
  inname =
  (
    [1] = force
  )
  stname =
  (
    [1] = x_1
    [2] = x_2
  )
  nz = 0
  outname =
  (
    [1] = position
  )
  a =

     0.00000   1.00000
    -0.30000   0.00000

  b =

    0.00000
    0.10000

  c =

    1  0

  d = 0
  yd = 0
  tsam = 0
  n = 2
  sys =

    2  0  0  1

}

octave:119> sys2tf(sys)
error: A(I) = X: X must be a scalar or a vector with same length as I
error: assignment failed, or no method for `matrix = matrix'
error: evaluating assignment expression near line 64, column 11
error: evaluating for command near line 45, column 3
error: called from `zginit' in file 
`/usr/local/share/octave/2.1.38/m/control/util/zginit.m'
error: evaluating assignment expression near line 59, column 6
error: called from `__zgpbal__' in file 
`/usr/local/share/octave/2.1.38/m/control/util/__zgpbal__.m'
error: evaluating assignment expression near line 81, column 8
error: called from `tzero' in file 
`/usr/local/share/octave/2.1.38/m/control/base/tzero.m'
error: evaluating if command near line 57, column 3
error: called from `ss2tf' in file 
`/usr/local/share/octave/2.1.38/m/control/system/ss2tf.m'
error: evaluating if command near line 77, column 5
error: evaluating if command near line 72, column 3
error: called from `sysupdate' in file 
`/usr/local/share/octave/2.1.38/m/control/system/sysupdate.m'
error: evaluating assignment expression near line 53, column 8
error: called from `sys2tf' in file 
`/usr/local/share/octave/2.1.38/m/control/system/sys2tf.m'
octave:119> 


Are these known issues ?

Thanks,

 Nick

-- 
Part 3 MEng Cybernetics; Reading, UK       http://www.nickpiper.co.uk/
GPG Encrypted mail welcome!                             1024D/3ED8B27F
Choose life. Be Vegan :-) Please reduce needless cruelty + suffering !



-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------