Mathematica 9 is now available
Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2008

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

Search the Archive

Re: Transform list of numbers into pure functions using replace rule

  • To: mathgroup at smc.vnet.net
  • Subject: [mg89483] Re: Transform list of numbers into pure functions using replace rule
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Tue, 10 Jun 2008 07:14:02 -0400 (EDT)
  • Organization: Uni Leipzig
  • References: <g2lb8t$964$1@smc.vnet.net>
  • Reply-to: kuska at informatik.uni-leipzig.de

Hi,

{1, 2, f[x]} /. x_?NumericQ :> Function @@ {x}

??

Regards
   Jens


Mac wrote:
> Hello,
> 
> I'm developed a program to invert satellite observations into
> geophysical variables such as forest biomass. One of the input
> parameters are the errors in the observation channels which can be
> either constant or a function. To be consistent the program expects
> all errors to be functions but they can also be constant functions
> e.g. if the error is 4 then the input parameter is "4&".
> 
> I've however hit a problem with the replacement rule that allows me to
> transform all input errors into a function. The following works as
> expected in that constants in the list are transformed into virtual
> functions and functions in the list are left alone.
> 
> In[40]:= If[NumberQ[#], ToExpression[ToString[#] <> "&"], #] & /@ {1,
>   2, 3 &, f[x]}
> 
> Out[40]= {1 &, 2 &, 3 &, f[x]}
> 
> However, I cannot find a replacement rule to do the same job. Here is
> one try:
> 
> In[39]:= {1, 2, f[x]} /. x_ /; NumberQ -> Hold[x &]
> 
> Out[39]= {1, 2, f[x]}
> 
> Any help would be appreciated.
> 
> Mac
> 
> 


  • Prev by Date: Re: Notebooks location
  • Next by Date: Re: Transform list of numbers into pure functions using replace rule
  • Previous by thread: Re: Transform list of numbers into pure functions using replace rule
  • Next by thread: Re: Transform list of numbers into pure functions using replace rule