Re: ListCorrelate
- To: mathgroup at smc.vnet.net
- Subject: [mg37546] Re: ListCorrelate
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Mon, 4 Nov 2002 02:44:30 -0500 (EST)
- References: <aq07kc$5qp$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Mike, Daniel,
Clear["`*"];
j=2;
ll = Array[aa,7];
With[{kernel = Unevaluated[{(j-1)*X,Y,(j+++1)*Z}]},
ListCorrelate[kernel,ll]]
{X aa[1]+Y aa[2]+3 Z aa[3],2 X aa[2]+Y aa[3]+4 Z aa[4],
3 X aa[3]+Y aa[4]+5 Z aa[5],4 X aa[4]+Y aa[5]+6 Z aa[6],
5 X aa[5]+Y aa[6]+7 Z aa[7]}
--
Allan
---------------------
Allan Hayes
Mathematica Training and Consulting
Leicester UK
www.haystack.demon.co.uk
hay at haystack.demon.co.uk
Voice: +44 (0)116 271 4198
Fax: +44 (0)870 164 0565
"Mike" <mikeh1980 at optusnet.com.au> wrote in message
news:aq07kc$5qp$1 at smc.vnet.net...
> I think it is probably possible to use ListCorrelate in the following way:
>
> ListCorrelate[{(j-1)*X, Y,(j+1)*Z},{a,b,c,d,....}]
>
> Where j changes as they move along the row. The change reflects the
position
> or part of the element they are operating on. For example initially j =2
> then 3, 4...and the output would be
>
> {(2-1)*X*a+Y*b+(2+1)*Z*c,(3-1)*X*b+Y*c+(3+1)*Z*d, ...}
>
> I've tried to replace Times in ListCorrelate with a function that will do
> this but had no success. If I can get this simple example to work I will
> take this and Map a Matrix onto it:
>
> ListCorrelate[{(j-1)*X, Y,(j+1)*Z},#]&/@ list
>
> This will be part of a larger function which I've written alternatively
> using MapThread and Map but I think it should work a lot faster if I can
> incorporate ListCorrelate.
>
> Thanks
>
> Mike
>
>
>