#928 is(equal(%i,0))

closed
nobody
Lisp Core (471)
8
2006-12-19
2006-05-15
No

(%i9) is(equal(%i,0));
`sign' called on an imaginary argument:

(%i10) is(equal(und,0));
`sign' called on `und'.

I claim that both of these should evaluate to false.
It seems that equal should call csign, not $sign.

Barton

Discussion

  • Robert Dodier

    Robert Dodier - 2006-05-16

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    Agreed, these are bugs, and these should both yield false.

     
  • Robert Dodier

    Robert Dodier - 2006-06-05

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    Fix title of this item (equla --> equal).

     
  • Robert Dodier

    Robert Dodier - 2006-06-05
    • summary: is(equla(%i,0)) --> is(equal(%i,0))
     
  • Robert Dodier

    Robert Dodier - 2006-08-26

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    user_id=501686

    Increase priority. This is a serious hindrance.

     
  • Robert Dodier

    Robert Dodier - 2006-08-26
    • priority: 5 --> 8
     
  • Nobody/Anonymous

    Logged In: NO

    Well, two complex numbers are equal if and only if their
    real and imaginary parts are equal. That is

    "a + ib = c + id" if and only if "a = c" and "b = d"

    If the complex number is in the polar form, they are equal
    if and only if they have the same magnitude and direction,
    that is

    "a*%e^(%i*b) = c*%e^(%i*d)" if and only if "a = c" and "b = d"

    Generally speaking, any two vectors are equal if and only if
    they are equal in its components. That is

    [x[1],x[2],x[3],...,x[n]] = [y[1],y[2],y[3],...y[m]]
    only when
    "n = m" and "x[i]=y[i]" for all 'i' between 1 and n
    Otherwise, they are not equal

    I hope this can help to improve Maxima

    --Mario/Mexico

     
  • Robert Dodier

    Robert Dodier - 2006-12-19

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    Originator: NO

    Fixed by r1.16 src/compar.lisp (by Barton Willis).

     
  • Robert Dodier

    Robert Dodier - 2006-12-19
    • status: open --> closed
     

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