[Maxima-bugs] [ maxima-Bugs-619927 ] (-1.0b0)^(1/3) vs (-1.0d0)^(1/3)

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Bugs item #619927, was opened at 2002-10-07 17:05
Message generated for change (Comment added) made by dgildea
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Category: Lisp Core - Simplification
Group: None
>Status: Closed
>Resolution: Fixed
Priority: 5
Private: No
Submitted By: Barton Willis (willisb)
Assigned to: Nobody/Anonymous (nobody)
Summary: (-1.0b0)^(1/3) vs (-1.0d0)^(1/3)

Initial Comment:

With domain : real, (-1.0b0)^(1.3) evaluates to its principal value while (-1.0d0)^(1/3) evaluates
using the real-branch rule.

(C24) domain : real;
(D24) 				       REAL
(C25) (-1.0b0)^(1/3);
(D25) 			 8.660254037844387B-1 %I + 5.0B-1
(C26) (-1.0d0)^(1/3);
(D26) 				      - 1.0
(C27) 


Barton

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>Comment By: Dan Gildea (dgildea)
Date: 2009-06-14 17:13

Message:
In float.lisp rev 1.55, made bfloat consistent with float.

(%i5) (-1b0)^(1/3);
(%o5) -1.0b0
(%i6) (-1.0)^(1/3);
(%o6) -1.0
(%i7) (-1b0)^(1/3),domain:complex;
(%o7) 1.0b0*(-1)^(1/3)
(%i8) (-1.0)^(1/3),domain:complex;
(%o8) 1.0*(-1)^(1/3)
(%i9) (-1b0)^(1/3),domain:complex,m1pbranch:true;
(%o9) 1.0b0*(sqrt(3)*%i/2+1/2)
(%i10) (-1.0)^(1/3),domain:complex,m1pbranch:true;
(%o10) 1.0*(sqrt(3)*%i/2+1/2)


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