These issues should be fixed with version 4.0.0 of the control package.

Oops. I meant the test suite for the control package of course...

@Markus, all the cases you have posted affect functions that identify or approximate the input/output behavior of a system. Since the resulting state space representations are not unique (e.g. some states have different signs like in your cases). I have therefore changed the tests in order to just test the input/output behavior of the results, not the state space representation.

Could you please test again with the attached files?

(file #54442, file #54443, file #54444, file #54445)

Maybe this is related to bug #45008 where the use of OpenBLAS leads to failing tests (also the ones from SLICOT) whereas the tests pass when using BLAS.

Please, put this bug on hold. It manifests itself on a Debian unstable system, with Octave 6.2.0. However, I could not replicate it on a Debian experimental system. I will investigate this further.

The unit test for the bstmodred function in the control package (version 3.3.0) fails with the following error message:

octave:1> pkg load control
octave:2> test bstmodred
***** assert (Mo, Me, 1e-4);
!!!!! test failed
ASSERT errors for:  assert (Mo,Me,1e-4)

  Location  |  Observed  |  Expected  |  Reason
   (3,1)        2.9889      -2.9889      Abs err 5.9778 exceeds tol 0.0001 by 6
   (6,1)       0.69073      -0.6907      Abs err 1.3814 exceeds tol 0.0001 by 1
   (7,1)      -0.067554      0.0676      Abs err 0.13515 exceeds tol 0.0001 by 0.1
   (8,1)       -0.69073      0.6907      Abs err 1.3814 exceeds tol 0.0001 by 1
   (6,2)       0.68823      -0.6882      Abs err 1.3764 exceeds tol 0.0001 by 1
   (8,2)       0.68823      -0.6882      Abs err 1.3764 exceeds tol 0.0001 by 1
   (1,3)       -6.5947       6.5947      Abs err 13.189 exceeds tol 0.0001 by 1e+01
   (5,3)        2.0339      -2.0339      Abs err 4.0678 exceeds tol 0.0001 by 4
   (6,4)      -0.095762      0.0958      Abs err 0.19156 exceeds tol 0.0001 by 0.2
   (8,4)      -0.095762      0.0958      Abs err 0.19156 exceeds tol 0.0001 by 0.2
   (3,5)       0.36919      -0.3692      Abs err 0.73839 exceeds tol 0.0001 by 0.7
   (6,5)      0.0037553     -0.0038      Abs err 0.0075553 exceeds tol 0.0001 by 0.007
   (7,5)       0.75223      -0.7522      Abs err 1.5044 exceeds tol 0.0001 by 2
   (8,5)      -0.0037553     0.0038      Abs err 0.0075553 exceeds tol 0.0001 by 0.007
   (1,6)       -0.13307      0.1331      Abs err 0.26617 exceeds tol 0.0001 by 0.3
   (2,6)       0.086198     -0.0862      Abs err 0.1724 exceeds tol 0.0001 by 0.2
   (4,6)        3.5767      -3.5767      Abs err 7.1534 exceeds tol 0.0001 by 7
   (5,6)        2.3033      -2.3033      Abs err 4.6066 exceeds tol 0.0001 by 5
   (1,7)       0.13307      -0.1331      Abs err 0.26617 exceeds tol 0.0001 by 0.3
   (2,7)       0.086198     -0.0862      Abs err 0.1724 exceeds tol 0.0001 by 0.2
   (4,7)        3.5767      -3.5767      Abs err 7.1534 exceeds tol 0.0001 by 7
   (5,7)       -2.3033       2.3033      Abs err 4.6066 exceeds tol 0.0001 by 5
shared variables   scalar structure containing the fields:

[…]

This issue has been already reported in the past. The patch attached to this bug report fixes the problem. It simply flips the signs of some expected values.