Re: Redefine Arg to return a value from 0 to 2 pi

*To*: mathgroup at smc.vnet.net*Subject*: [mg80494] Re: Redefine Arg to return a value from 0 to 2 pi*From*: chuck009 <dmilioto at comcast.com>*Date*: Thu, 23 Aug 2007 01:19:30 -0400 (EDT)

Hello guys. Thanks for replying. I wish to redefine the built-in Arg command so that I can have better control over which sheet of multi-functions are plotted. For example, if I just plot: Plot3D[Im[Log[z]] /. z -> x + I*y, {x, -2, 2}, {y, -2, 2}] Then Mathematica uses the principle sheet with the branch-cut along the negative real axis. Now, if I were to re-define the Arg function to return a value between 0 and 2 pi then Mathematica would use my re-defined Arg function internally and display the branch-cut along the positive real axis. I'm working on the Riemann surface for MathieuCharacteristicA and would like to have Mathematica internally use the branch 0 to 2 pi to "extend" the principle sheet farther automatically.