Hello,
It is not yet a good bug report, because I've not yet got a simple
function to lead to such results. For now I observe strange behaviour
of maxima in case of expression of the form 0/0. Let us take the
following function:
f(a,b,c):= (((a^2-1)*b^4+(1-a^4)*b^2+a^4-a^2)*c^4*LOG(c)
+((1-a^2)*b^4*LOG(b)+a^4*LOG(a)*b^2-a^4*LOG(a))*c^4
+((a^4-1)*b^4*LOG(b)-a^4*LOG(a)*b^4+a^4*LOG(a))*c^2
+(a^2-a^4)*b^4*LOG(b)+a^4*LOG(a)*b^4-a^4*LOG(a)*b^2)
/((((a^2-1)*b^2-a^4+a^2)*c^2+(a^2-a^4)*b^2+a^6-a^4)
*((b^2-1)*c^4+(1-b^4)*c^2+b^4-b^2));
It is easy to notice, that for c=1 it has the form of 0/0 (but the
limit c->1 is finit). If I ask maxima to calculate, say:
(C30) f(0.01,0.1,1);
I get:
(D30) 0.07492989580642
which is in no sence correct. (The correct limit for c->1 is
0.48137500492202). And no words about division by zero! Funny, for
other parameters I can get this message:
(C34) f(0.1,0.5,1);
Division by 0
#0: f(a=0.1,b=0.5,c=1)
-- an error. Quitting. To debug this try DEBUGMODE(TRUE);)
Let me not again -- denomenator of this expression is exactly zero for
c=1.
Fedor
--
Fedor Bezrukov http://www.inr.ac.ru/~fedor/