Re: Dot Product in Cylindrical Coordinates

*To*: mathgroup at smc.vnet.net*Subject*: [mg69285] Re: Dot Product in Cylindrical Coordinates*From*: p-valko at tamu.edu*Date*: Tue, 5 Sep 2006 05:30:58 -0400 (EDT)*References*: <eddqs4$406$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

No Hodge star here, but if you mean by dot product the product of their Cartesian lengths multiplied by the Cos of the angle between them, then In[1]:= << "Calculus`VectorAnalysis`" vcar1=CoordinatesToCartesian[{1, Pi/4, 0},Cylindrical]; vcar2=CoordinatesToCartesian[ {2, 0, 1},Cylindrical]; vcar1.vcar2//InputForm Out[4]//InputForm= Sqrt[2] David Park wrote: > Sergio, > > I get 2 also, using an independent calculation using differential forms and > Hodge star. > > I think the Mathematica vector calculus package get confused between the > points and the tangent vectors. > > David Park > djmp at earthlink.net > http://home.earthlink.net/~djmp/ > > From: Sergio Miguel Terrazas Porras [mailto:sterraza at uacj.mx] To: mathgroup at smc.vnet.net > > Hello group: > > When I calculate the dot product of vectors {1,Pi/4,0} and {2,0,1} in > Cylindrical Coordinates Mathematica 5.1 returns the result Sqrt[2], when the > result should be 2. > What is going on ? > Thanks > Sergio Terrazas