[Octave-bug-tracker] [bug #45336] control 2.8.2 - error on MIMO tf multiply

[Nick Jankowski]

URL:
  <http://savannah.gnu.org/bugs/?45336>

                 Summary: control 2.8.2 - error on MIMO tf multiply 
                 Project: GNU Octave
            Submitted by: nrjank
            Submitted on: Wed 17 Jun 2015 02:38:23 AM GMT
                Category: Octave Forge Package
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.0.0
        Operating System: Microsoft Windows

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Details:

after upgrading to 2.8.2, a script that worked under 2.8.1 started throwing an
error. here's a simpler version that produces the same error:



>> a1 = tf({[2 24],[12];[1 48 0],[2 24]},{[-1 24],[-1 24];[-4 96],[-1 24]});
>> a1**2;
warning: tf: converting to minimal state-space for MIMO TF interconnections
warning: called from
    __sys_connect__ at line 115 column 5
    mtimes at line 58 column 7
    mpower at line 56 column 12

>> a1**3;
warning: tf: converting to minimal state-space for MIMO TF interconnections
warning: called from
    __sys_connect__ at line 115 column 5
    mtimes at line 58 column 7
    mpower at line 56 column 12
warning: tf: converting to minimal state-space for MIMO TF interconnections

>> a1**4;
warning: tf: converting to minimal state-space for MIMO TF interconnections
warning: called from
    __sys_connect__ at line 115 column 5
    mtimes at line 58 column 7
    mpower at line 56 column 12
warning: tf: converting to minimal state-space for MIMO TF interconnections
warning: tf: converting to minimal state-space for MIMO TF interconnections
error: subscript indices must be either positive integers less than 2^31 or
logicals
error: called from
    __sys2ss__> at line -1 column -1
    __sys2ss__ at line 50 column 10
    ss at line 175 column 17
    __sys_connect__ at line 116 column 9
    mtimes at line 58 column 7
    mpower at line 56 column 12
error: evaluating argument list element number 1
error: called from
    __sys_connect__ at line 116 column 9
    mtimes at line 58 column 7
    mpower at line 56 column 12
error: evaluating argument list element number 1
error: called from
    __sys_connect__ at line 116 column 9
    mtimes at line 58 column 7
    mpower at line 56 column 12



don't know if this is related to Bug #45334, which relates to odd outputs from
multiple tf multiplies. But this error above is new to 2.8.2, and the case
described in #45334 does not create this error in 2.8.1 or 2.8.2.




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