# Re: [R] coefficient of polynomial expansion

From: Martin Maechler <maechler_at_stat.math.ethz.ch>
Date: Tue 09 Aug 2005 - 00:46:44 EST

>>>>> "Peter" == Peter Yang <peterwyang@gmail.com>
>>>>> on Mon, 8 Aug 2005 09:11:47 -0400 writes:

Peter> Hi, I would like to get the coefficient of polynomial     Peter> expansion. For example,

```    Peter> (1+ x)^2 = 1 + 2x + x^2, and the coefficients are 1,
Peter> 2 and 1.  (1 + x + x^2)^3 = 1 + 3*x + 6*x^2 + 7*x^3 +
Peter> 6*x^4 + 3*x^5 + x^6, and the coefficients are 1, 3,
Peter> 6, 7, 6, 3, and 1.

```

Peter> I know that we can use polynom library. Is there any     Peter> other way to do it without loading a library.

yes, load the polynom *package* (from the library where the

• *package* is installed)

What's bad about using polynom? IMO it is very nice, very useful package for the purpose it was written.

Using packages for tasks they were written is one of the strengths of the R project,
so why are you reluctant?

Martin

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