Re: sys2tf seems broken in 2.1.38

[Nicholas Piper]

On Thu, 31 Oct 2002, John W. Eaton wrote:

> | 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'

> Please try the following patch.  It should fix this problem as well as
> another that caused other examples in DEMOcontrol to fail.

Thank you, that does appear to fix the DEMOcontrol (at least, that
specific demo).

However, I'm still having troubles with the Control tools in general.
My system is constructed from:

A=[0 1; -k/m -b/m];B=[0;1/m];C=[1 0];D=[0];
sys = ss2sys(A,B,C,D)

sysout(sys,'tf') fails with :
 ** On entry to DGESVD parameter number 13 had an illegal value
Input(s)
      1: u_1

Output(s):
     1: y_1

error: exception encountered in Fortran subroutine dgesvd_
error: unrecoverable error in dgesvd
error: evaluating assignment expression near line 41, column 11
error: evaluating if command near line 40, column 3
error: called from `rank' in file 
`/usr/local/share/octave/2.1.38/m/linear-algebra/rank.m'
error: evaluating assignment expression near line 72, column 6
error: called from `zgscal' in file 
`/usr/local/share/octave/2.1.38/m/control/util/zgscal.m'
error: evaluating assignment expression near line 67, column 8
error: evaluating if command near line 65, column 3
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'

I expect this to work, because I'm doing the same as the demo, just
with my own system.

step(sys) fails with a very similar error:
 ** On entry to DGESVD parameter number 13 had an illegal value
error: exception encountered in Fortran subroutine dgesvd_
error: unrecoverable error in dgesvd
error: evaluating assignment expression near line 44, column 11
error: evaluating if command near line 40, column 3
error: called from `rank' in file 
`/usr/local/share/octave/2.1.38/m/linear-algebra/rank.m'
error: evaluating assignment expression near line 42, column 5
error: called from `dcgain' in file 
`/usr/local/share/octave/2.1.38/m/control/base/dcgain.m'
error: evaluating assignment expression near line 230, column 14
error: evaluating if command near line 225, column 2
error: evaluating if command near line 224, column 7
error: evaluating if command near line 216, column 5
error: called from `__stepimp__' in file 
`/usr/local/share/octave/2.1.38/m/control/base/__stepimp__.m'
error: evaluating switch command near line 67, column 5
error: evaluating if command near line 66, column 3
error: called from `step' in file 
`/usr/local/share/octave/2.1.38/m/control/base/step.m'

Is this the right place to submit these errors, or should I use a bug
mailing list ? (It's possible I'm in error to try and call the
functions I did, so maybe not :-) )

Thanks,

 Nick

-- 
Part 3 MEng Cybernetics; Reading, UK       http://www.nickpiper.co.uk/
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