Re: Dimensions and Variables

*To*: mathgroup at smc.vnet.net*Subject*: [mg13728] Re: Dimensions and Variables*From*: Paul Abbott <paul at physics.uwa.edu.au>*Date*: Wed, 19 Aug 1998 01:38:20 -0400*Organization*: University of Western Australia*References*: <6r102b$fi7@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Naum Phleger wrote: > 1)Why does Dimensions comand return 2 for x*Cos[y]? I need to check > dimensions of quantities and this makes it dificult to do. The Dimensions function in Mathematica yields the structure of expressions, e.g., for a matrix, In[1]:= Dimensions[{{a, b}, {c, d}}] Out[1]= {2, 2} You may find that the Miscellaneous`Units` package (which comes with Mathematica) is relevant to what you are after. > 3)Does Mathematica Know anything about map projections. I have a vector > feild of the sky and I want to plot it in a certin projection. All I > have been able to do so far is plot vectors on square euclidian space. Have a look at Miscellaneous`WorldPlot` (and also Graphics`ComplexMap`). Cheers, Paul ____________________________________________________________________ Paul Abbott Phone: +61-8-9380-2734 Department of Physics Fax: +61-8-9380-1014 The University of Western Australia Nedlands WA 6907 mailto:paul at physics.uwa.edu.au AUSTRALIA http://www.physics.uwa.edu.au/~paul God IS a weakly left-handed dice player ____________________________________________________________________