You are right. It should actually return Vector(0), i.e. sympy.physics.vector.vector.Vector (with the new physics.vector module) or sympy.physics.mechanics.essential.Vector (for the old version of the mechanics core). I'll fix this.
On Friday, February 7, 2014 3:14:54 PM UTC+5:30, TARUN GABA wrote: > > Hi, > I am curious about how the Vector.express function behaves, when we call > it from a Zero Vector. > For example: > > >>>from sympy.physics.mechanics.point import Point > >>>A = Point() > >>>type(A) > sympy.physics.mechanics.point.Point > >>>A.pos_from(A) > 0 > >>>type(A.pos_from(A)) > sympy.physics.mechanics.essential.Vector > > Now When I call "express" method from this particular Zero Vector, say "I" > is my sympy.physics.mechanics.essential.ReferenceFrame > > Now, > >>> A.pos_from(A).express(I) > 0 > >>> type(A.pos_from(A).express(I)) > sympy.core.numbers.Zero > > I am not sure whether it is a bug, or it should behave like this only. > Shouldn't it return sympy.core.numbers.Vector instead? > > Thanks > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
