Re: collect derivatives
- To: mathgroup at smc.vnet.net
- Subject: [mg23280] Re: [mg23259] collect derivatives
- From: Andrzej Kozlowski <andrzej at platon.c.u-tokyo.ac.jp>
- Date: Sun, 30 Apr 2000 21:13:32 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
on 00.4.30 11:05 AM, Robert at robert.schuerhuber at gmx.at wrote:
> is there a way to use "collect[]" to collect all terms with a specific
> derivative, e.g. to produce something like
>
> z''[x] u[x] + z'[x] (u'[x]+u[x]) + z[x]
>
> ?
>
> thanks, robert
>
>
Use patterns in Collect, e.g.
In[1]:=
(_)
Collect[z[x] + u[x] z'[x] + u'[x] z'[x] + u[x] z''[x], z [x]]
Out[1]=
z[x] + (u[x] + u'[x]) z'[x] + u[x] z''[x]
--
Andrzej Kozlowski
Toyama International University
Toyama, Japan
http://sigma.tuins.ac.jp/