I don't know if this is the source of the problem or not, but I would recommend against using Rational(str(786959127181/10000000000)). What this is doing is first converting 786959127181/10000000000 into a float, then trying to convert it back again. This feature is useful if you only have the floating point representation of a number, but you have the full Rational form already. Thus, you should just use Rational(786959127181, 10000000000).
Worse, if you don't happen to have "from __future__ import division", it will truncate the number first (integer division). (By the way, if any behavior in sympy seems to go against what is documented, it is probably a bug) Aaron Meurer On Sep 8, 2010, at 5:17 AM, [email protected] wrote: > Hi all, > I got the following code: > > print "ell circle 1" > p1= Point(Rational(str(-351)), Rational(str(-2))) > eci1=intersection(Ellipse(p1, Rational(str(50)), Rational(str(100))), > Circle(p1, Rational(str(786959127181/10000000000)))) > for p in eci1: > print "Point ",p > > print "ell circle 2" > p2=Point(Rational(str(0)), Rational(str(0))) > eci2=intersection(Ellipse(p2, Rational(str(50)), > Rational(str(100))),Circle(p2, Rational(str(786959127181/10000000000)))) > for p in eci2: > print "Point ",p > > If you run this code you will notice that the intersection points are similar > in both the intersection: > ell circle 1 > Point Point(-2*2937**(1/2)/3, 32*42**(1/2)/3) > Point Point(2*2937**(1/2)/3, -32*42**(1/2)/3) > Point Point(-2*2937**(1/2)/3, -32*42**(1/2)/3) > Point Point(2*2937**(1/2)/3, 32*42**(1/2)/3) > ell circle 2 > Point Point(-2*2937**(1/2)/3, 32*42**(1/2)/3) > Point Point(2*2937**(1/2)/3, -32*42**(1/2)/3) > Point Point(-2*2937**(1/2)/3, -32*42**(1/2)/3) > Point Point(2*2937**(1/2)/3, 32*42**(1/2)/3) > > it seems that the intersection is made like the two entity are centred in the > 0,0 coordinate. > It's a bug or it have to work in this way ? > > Regards, > Matteo > > > > > > > > > > > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
