[Scilab-users] det([]) changed in Scilab 6.0

[Samuel Gougeon]

Hello,

While updating "help empty" after changes in Scilab 6 about inequality 
comparisons with [],
i have found that det([]) is changed:

  * 5.5: det([]) => 1
  * 6.0: det([]) => 0

I don't know if this modification is intentional.
I am wondering about the added value of this change:

  * If we consider the property for square matrices A & B:
            det(A*B) = det(A)*det(B)    (1)
    setting det([])=0 better complies with it. Indeed, since []*B => [],
    we have now det([]*B) = det([])*det(B) = 0*k = 0 = det([])  : OK

  * In another hand, we should also have :
    det(1/A) = 1/det(A)     (2)
    Since inv([]) => [], setting det([]) => 1  complied with (2),
    while det([]) => 0  no longer does it.

Settingdet([]) => [] would comply with both (1) and (2).

Let's note that Octave returns 1.

So, shall we restore det([]) ==1, or keep 0, or set it to [] ?

What's the improvement in changing det([]) to 0 ?

Regards
Samuel

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