MathGroup Archive 2000

[Date Index] [Thread Index] [Author Index]

Search the Archive

RE: collect derivatives


> From: Robert [mailto:robert.schuerhuber at gmx.at]
To: mathgroup at smc.vnet.net
> 
> 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

Robert,

Easy!

e1 = z''[x] u[x] + z'[x] (u'[x] + u[x]) + z[x] // Expand;

Collect[e1, {Derivative[_][z][x]}]

z[x]+(u[x] + u'[x])z'[x] + u[x]z''[x]

David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/ 


  • Prev by Date: spectroscopy
  • Next by Date: Re: DSolve, it should be beautiful...
  • Previous by thread: collect derivatives
  • Next by thread: Re: collect derivatives