Re: Difference table via DifferenceDelta[ ]. Why do I need two Table[ ] calls?
- To: mathgroup at smc.vnet.net
- Subject: [mg121177] Re: Difference table via DifferenceDelta[ ]. Why do I need two Table[ ] calls?
- From: "Christopher O. Young" <cy56 at comcast.net>
- Date: Sat, 3 Sep 2011 08:03:15 -0400 (EDT)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
Thanks a lot, using Differences[ ] seems like the way to go here; both
faster and more concise.
On 9/1/11 6:07 AM, in article j3nlgm$p31$1 at smc.vnet.net, "Peter Pein"
<petsie at dordos.net> wrote:
> Am 31.08.2011 13:41, schrieb Christopher O. Young:
>> The following gives me a difference table for x^3, but it would be nice if I
>> could do it with only 1 Table call.
>>
>> Grid[
>> Table[
>> Table[
>> DifferenceDelta[x^3, {x, n}] // Evaluate,
>> {x, -6, 6 - n + 1}
>> ]
>> , {n, 1, 3}
>> ],
>> Alignment -> Right
>> ]
>>
>> The following hangs up, though. I have to abort it after several minutes of
>> nothing happening.
>>
>> Table[
>> DifferenceDelta[x^3, {x, n}] // Evaluate,
>> {x, -6, 6},
>> {n, 1, 3}
>> ]
>>
>> Any help appreciated.
>>
>> Chris Young
>> cy56 at comcast.net
>>
>>
>
> Hi Christopher,
>
> I would use
>
> In[1]:= Rest@NestList[Differences, Range[-6, 7]^3, 3]
>
> Out[1]=
> {{91, 61, 37, 19, 7, 1, 1, 7, 19, 37, 61, 91, 127},
> {-30, -24, -18, -12, -6, 0, 6, 12, 18, 24, 30, 36},
> {6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6}}
>
> to get the values.
>
> Peter
>