The angle of a cylindrical vector should not contribute to its length, so I was expecting the root of 25, or 5. Where did I go wrong? Mathematica 9 newbie SetCoordinates[Cylindrical[r, \[Theta], z]] CoordinateSystem w = {3, 2, 4} Norm[w] (w . w)^.5 CoordinateSystem I get; Cylindrical[r, \[Theta], z] Cylindrical {3, 2, 4} Sqrt[29] 5.38516 Cylindrical

The code you have requires loading the old package. The built-in vector analysis functions have different names or different ways to obtain the same output. See http://reference.wolfram.com/language/Compatibility/tutorial/VectorAnalysis.html or its built-in equivalent, Compatibility/tutorial/VectorAnalysis under Help - Wolfram Documentation. The above tutorial suggests replacing DotProduct from the old package with a user function that converts the vectors to Cartesian, then takes the ordinary Dot product. In[1]:= dotProduct[a_, b_, chart_] := CoordinateTransform[chart -> "Cartesian", a].CoordinateTransform[ chart -> "Cartesian", b] In[2]:= dotProduct[{3, 2, 4}, {3, 2, 4}, "Cylindrical"] // N Out[2]= 25. Using the package works for me with 10.0.0 and 10.0.1. In[1]:= Needs["VectorAnalysis`"] General::obspkg: VectorAnalysis` is now obsolete. The legacy version being loaded may conflict with current functionality. See the Compatibility Guide for updating information. In[2]:= DotProduct[{3, 2, 4}, {3, 2, 4}, Cylindrical] 2 2 Out[2]= 16 + 9 Cos[2] + 9 Sin[2] In[3]:= Simplify[%] Out[3]= 25 In[4]:= $Version Out[4]= 10.0 for Microsoft Windows (64-bit) (June 29, 2014) The attached notebook has three examples - your code without loading the package, your code after loading the package, and the new method. Attachments:

This question fell from strange cylindrical results as well. The problem I'm working is naturally cylindrical. I set Coords to Cyl and got to work. When I noticed things were not coming out as expected I started back tracking and found my Dots were not working correctly. The w of 3,2,4 was fabricated as a test of Dot because it would give obvious results in Cyl & Cart coordinates. I did see good documentation on translating between coordinate systems, but that really doesn't suit my needs for this case. Can I get someone to confirm if the above snippet does / doesn't work for them in mathematica 10?

I've sometimes gotten strange results with spherical or cylindrical coordinates. These can be avoided by transforming to good old Cartesian coordinates. With x=r cos\theta, y=r sin\theta, z=z , wcyl={3,2,4} becomes wcart={3 cos(2), 3 sin(2), 4} , etc. Do you really have theta=2 radians? Actually, it looks like w={3,2,4} is already in Cartesian coordinates, so w.w=29.

norm of a cylindrical vector?