Re: Re: Help please: Summing a list
- To: mathgroup at smc.vnet.net
- Subject: [mg13587] Re: [mg13555] Re: [mg13480] Help please: Summing a list
- From: Jon Prudhomme <prudhomj at elwha.evergreen.edu>
- Date: Mon, 3 Aug 1998 03:53:49 -0400
- Sender: owner-wri-mathgroup at wolfram.com
Rob, I think it would be easier to try this -
PP=Table[Apply[Plus,Take[P,n]],{n,1,i}]
Jon Prudhomme
The Evergreen State College
On Sat, 1 Aug 1998, Keith S. Mersman wrote:
> Rob,
>
> I think you want to do something like this:
>
> First, set up your original table:
>
> tab=Table[x,{x,0,110}]
>
> Then, assign a name to each of these entries like:
>
> Clear[P];
> Table[P[i]=tab[[i]],{i,1,111}]
>
> This, this let P[i] be the i-1 entry in the table (labeled tab)
>
> Now, sum these values and label the totals:
>
> Table[PP[i]=Sum[P[n],{n,1,i}],{i,1,111}]
>
> This makes PP[i] be the sum of the first i entries of the orinal table.
>
> Now, creata a new table with these values:
>
> newtab=Table[PP[i],{i,1,111}]
>
> Hence, newtab is now a list with the ith value as the sum as the sum of
> the first i entries of tab. Let me know if this is what you wanted.
>
>
> On Sun, 26 Jul 1998 robpetersonSPAMME at iname.com wrote:
>
> > I make a list of numbers, eg:
> >
> > P=Table[6,{x,0,110}]; (I have a more interesting list to use later if I
> > get this working)
> >
> > Now I want to make another list PP in which each entry PP[[i]] is the
> > sum of P's first i entries. I try
> >
> > PP[[i]]:=Sum[P[[n]],{n,0,i}];
> >
> > At the definition, I get the following error: Part::"pspec":
> > "Part specification \!\(n\) is neither an integer nor a list of
> > integers."
> >
> > I don't know how to make n an integer. In the definition of Sum[], it
> > seems n is an integer unless you add a forth parameter "di" in the
> > specification list such as
> > Sum[f, {i, imin, imax, di}]
> >
> > Can anyone help me to generate this second list?
> >
> > Thanks, Rob
> >
> >
>
>
>