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## ln(0), bug in Calc?

**From**: |
Neon Absentius |

**Subject**: |
ln(0), bug in Calc? |

**Date**: |
Thu, 6 Oct 2005 11:32:03 +0000 |

**User-agent**: |
Mutt/1.4.2.1i |

When asked to solve the equation e^x = 0, Calc returns ln(0) as the answer.
It indicates in the echo area:
Logarithm of zero: 0 [w=more] ;; I press w
Choosing 0 for arbitrary integer in solution [w=more] ;; I press w
Logarithm of zero: 0 [w=more] ;; I press w
Number expected: e [w=more] ;; I press w
Number expected: e ;; I press w
(No further explanations available)
Apparently when the argument of log is non-positive Calc switches to
the (multivalued) complex logarithm and sets the integer in the
formula to 0. Of course this doesn't make sence when the argument of
the logarithm is 0. This is confirmed by setting the Hyperbolic flag.
Then I get the answer
x = (s1 > 0 ? []_n1 : ln(0) + 2 pi i n2)
and in the echo area "Logarithm of zero: 0".
--
There is no national science just as there is no national
multiplication table; what is national is no longer science.
-- Anton Checov

**ln(0), bug in Calc?**,
*Neon Absentius* **<=**