[Octave-bug-tracker] [bug #39044] sign function gives wrong answer for complex numbers.

[Robert Jacobs]

URL:
  <http://savannah.gnu.org/bugs/?39044>

                 Summary: sign function gives wrong answer for complex
numbers.
                 Project: GNU Octave
            Submitted by: robertlj52
            Submitted on: Wed 22 May 2013 09:21:25 PM GMT
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: Robert Jacobs
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 3.6.4
        Operating System: Microsoft Windows

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Details:

According to your documentation.
For complex arguments, `sign' returns `x ./ abs (X)'

But wikipedia defines a complex sign as  'x ./ (abs(x^2))'

Example:
a = 3 - 4i;
sign(a)
ans =  0.60000 - 0.80000i
a ./ sqrt(a.*a)
ans =  1





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