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.