[Mathematica] Sorting polynomial terms

1. Dec 4, 2011

jackmell

Hi. Can someone explain to me how to sort a Series so that the terms are in increasing powers of the exponent? For example the code:

myseries = Normal[ Series[Sqrt[1 - w], {w, 0, 5}]] /. w -> 1/z

produces
$$1-\frac{7}{256 z^5}-\frac{5}{128 z^4}-\frac{1}{16 z^3}-\frac{1}{8 z^2}-\frac{1}{2 z}$$

I would like them to be

$$1-\frac{1}{2z}-\frac{1}{8z^2}-\cdots$$

Thanks,
Jack

2. Dec 4, 2011

Hurkyl

Staff Emeritus
You can make a series around $\infty$. I don't know if that will appear sorted the way you want.

3. Dec 4, 2011

jackmell

Sorry. I'm afraid I'm having some problems with this. The series is being reported by Mathematica in increasing powers of 1/z like it should and like I'd want it to be.

Thanks Hurky for suggesting expanding it around infinity which is what I'd want for the function outside the unit circle.

Last edited: Dec 4, 2011
4. Dec 4, 2011

Bill Simpson

myseries = Normal[Series[Sqrt[1 - w], {w, 0, 5}]] /. w -> 1/z;

5. Dec 4, 2011

Hepth

Series[Sqrt[1 - w] /. w -> 1/z, {z, \[Infinity], 5}]

6. Dec 5, 2011

jackmell

Ok, thanks guys. TraditionalForm does what I wanted.