Re: 3.0.2 release (mingw32 check)

[John W. Eaton]

On 25-Aug-2008, Benjamin Lindner wrote:

| 3)
|  >>>>> processing 
| 
d:\files\admin\octaveforge_svn\trunk\octave-forge\admin\Windows\mingw32\octave\octave-3.0.2\scripts/strings\mat2str.m
|    ***** assert (mat2str ([-1/3 +i/7; 1/3 -i/7], [4 2]), 
| "[-0.3333+0i,0+0.14i;0.3333+0i,-0-0.14i]")
| !!!!! test failed
| error: assert (mat2str ([-1 / 3, +i / 7; 1 / 3, -i / 7], [4, 
| 2]),"[-0.3333+0i,0+0.14i;0.3333+0i,-0-0.14i]") expected
| [-0.3333+0i,0+0.14i;0.3333+0i,-0-0.14i]
| but got
| [-0.3333+0i,0+0.14i;0.3333+0i,0-0.14i]
| 
| Now this one, I don't consider a bug, rather a stange test.
| Why would I expect that -i has a real part of -0 (mind the sign!)?
| Doing
|    real(-i)
| yields
|    ans = 0
| as expected, and
|    sprintf("%f", real(-i))
| yields
|    0.00000
| also as expected.

On my system:

  octave:1> -i
  ans = -0 - 1i
  octave:2> real (-i)
  ans = -0

Remember that Octave does not have any pure imaginary data type.  So i
is stored as (0,1).  Negating that will result in (-0,-1) unless we
have a special case.  Is that justified?  I'm not sure.  If you want
to create (0,-1), then you have to write complex(0,-1).

jwe