Re: extracting powers and coefficients from a polynomial
- To: mathgroup at smc.vnet.net
- Subject: [mg49063] Re: [mg49040] extracting powers and coefficients from a polynomial
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Wed, 30 Jun 2004 05:34:11 -0400 (EDT)
- Reply-to: hanlonr at cox.net
- Sender: owner-wri-mathgroup at wolfram.com
expr=Sum[x^i,{i,6}]^3;
cl=CoefficientList[expr,x];
Select[Transpose[{Range[0,Length[cl]-1],cl}],#[[2]]!=0&] // TableForm
Bob Hanlon
>
> From: "AngleWyrm" <no_spam_anglewyrm at hotmail.com>
To: mathgroup at smc.vnet.net
> Date: 2004/06/29 Tue AM 04:50:22 EDT
> To: mathgroup at smc.vnet.net
> Subject: [mg49063] [mg49040] extracting powers and coefficients from a polynomial
>
> I have made a formula that produces a polynomial expansion, and I wish to
> extract the powers and coefficients into a list.
>
> Expand[(Sum[x^i, {i, 6}])^3]
> 1x^3 + 3x^4 + 6x^5 + 10x^6 + 15x^7 + 21x^8 + 25x^9 + 27x^10 +
27x^11 + 25x^12
> + 21x^13 + 15x^14 + 10x^15 + 6x^16 + 3x^17 + 1x^18
>
> How do I make a table of the powers and coefficents?
> 3, 1
> 4, 3
> 5, 6
> 6, 10
> ....
>
> --
> AngleWyrm
> The C++ hat random selection container:
> http://home.comcast.net/~anglewyrm/hat.html
>
>