Re: pretty output with HoldForm
- To: mathgroup at smc.vnet.net
- Subject: [mg70482] Re: pretty output with HoldForm
- From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
- Date: Tue, 17 Oct 2006 02:59:30 -0400 (EDT)
- Organization: Uni Leipzig
- References: <egva7f$rgs$1@smc.vnet.net>
Hi,
kl[n_] := HoldForm[ 1/(2n + 1) - 1/(4n + 2) -
1/(4n + 4)];
reihe = Sum[kl[n], {n, 1, 5}];
(reihe + Hold[] //.
HoldForm[a_] + b_. + Hold[c___] :> (d =
Evaluate[a];
Append[Hold[c], d] + b)) /. Hold[c___] :>
HoldForm[Plus[c]]
Regards
Jens
"Peter Breitfeld" <phbrf at t-online.de> schrieb im
Newsbeitrag news:egva7f$rgs$1 at smc.vnet.net...
|
| I want to get the following output for the
series:
|
| (1 - 1/2 - 1/4) + (1/3 - 1/6 - 1/8) + (1/5 -
1/10 - 1/12) +
| (1/7 - 1/14 - 1/16) . . .
|
| What I did was
|
| kl[n_]:=HoldForm[ 1/(2n+1)-1/(4n+2)-1/(4n+4)]
|
| then I enter eg:
|
| reihe= Sum[kl[n],{n,1,5}]
|
| This works quite good, but the fractions are
completely unevaluated
| (because of HoldForm, I know) and display as
|
| 1
| ----------
| 4 2 + 2
|
| But I want them displayed as
|
| 1
| --
| 10
|
| Is there a way to evaluate parts inside a
HoldForm, so that the
| fractions are evaluated but not the sums?
|
| Gruss Peter
| --
|
==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==-==
| Peter Breitfeld, Bad Saulgau, Germany --
http://www.pBreitfeld.de
|