[Octave-bug-tracker] [bug #54261] blkmm error for some size of input

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?54261>

                 Summary: blkmm error for some size of input
                 Project: GNU Octave
            Submitted by: None
            Submitted on: Sat 07 Jul 2018 11:52:19 AM UTC
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Unexpected Error
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: address@hidden
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 4.4.0
        Operating System: GNU/Linux

    _______________________________________________________

Details:

Let size(A)=[m,p,q], size(B)=[p,n,q], C=blkmm(A,B), then size(C)=[m,n,q].

If (m=0 and n=1) or (m=1 and p=0 and n!=1), then blkmm will raise the
following error:

 ** On entry to DGEMV  parameter number  6 had an illegal value
unknown error in fortran subroutine


This is a small issue, since it only raises errors for some size of empty
input.

The following test code will show the above result.

lim = 4;
a = randn(lim,lim,lim);
b = randn(lim,lim,lim);
err = [];
for m = 0:lim
for n = 0:lim
for p = 0:lim
for q = 0:lim
        try
                c = blkmm(a(1:m,1:p,1:q), b(1:p,1:n,1:q));
                assert(size_equal(c, zeros(m,n,q)));
        catch
                err = [err; m p n q];
                disp(lasterr);
        end
end
end
end
end
disp(err);


and the output of the above code is as follow.

 ** On entry to DGEMV  parameter number  6 had an illegal value
unknown error in fortran subroutine
......
 ** On entry to DGEMV  parameter number  6 had an illegal value
unknown error in fortran subroutine
   0   0   1   1
   0   0   1   2
   0   0   1   3
   0   0   1   4
   0   1   1   1
   0   1   1   2
   0   1   1   3
   0   1   1   4
   0   2   1   1
   0   2   1   2
   0   2   1   3
   0   2   1   4
   0   3   1   1
   0   3   1   2
   0   3   1   3
   0   3   1   4
   0   4   1   1
   0   4   1   2
   0   4   1   3
   0   4   1   4
   1   0   0   1
   1   0   0   2
   1   0   0   3
   1   0   0   4
   1   0   2   1
   1   0   2   2
   1   0   2   3
   1   0   2   4
   1   0   3   1
   1   0   3   2
   1   0   3   3
   1   0   3   4
   1   0   4   1
   1   0   4   2
   1   0   4   3
   1   0   4   4





    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?54261>

_______________________________________________
  Message sent via Savannah
  https://savannah.gnu.org/