Services & Resources / Wolfram Forums / MathGroup Archive
-----

MathGroup Archive 2010

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

Search the Archive

Branching on error messages?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg108946] Branching on error messages?
  • From: Jack L Goldberg 1 <jackgold at umich.edu>
  • Date: Thu, 8 Apr 2010 07:59:42 -0400 (EDT)

Hi Folks,

In a module I have written I call Reduce and in the most common case,  
Reduce does exactly what I want.  In some rarer cases, however, Reduce  
returns the error message

Reduce::nsmet: ... (basically, Reduce doesn't know how to simplify  
transcendental equations.)

Suppose in Line L6 of my module I have this code

L6 = Reduce[L5, var, Reals];

I want something like this instead,

L6 = If[ Reduce[L5, var, Reals] generates no error message,  
Reduce[L5,var,Reals], Module[ ... ];

So if there is an error message, we go to Module[...] which I hope  
corrects things by introducing numerical methods.

An alternative is this: Define newReduce which acts like Reduce when  
no error message of the type Reduce::nsmet occurs and uses my  
numerical techniques otherwise.

I am unsure how to code L6 or whether to explore defining my own newReduce?
Any guidance is appreciated, as usual.

Jack




  • Prev by Date: Bug in PadLeft/PadRight
  • Next by Date: Re: Collecting like terms after TrigReduce
  • Previous by thread: Re: Bug in PadLeft/PadRight
  • Next by thread: Re: Branching on error messages?