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

MathGroup Archive 2008

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

Search the Archive

Re: Defining Functions and Simplifying Solutions

  • To: mathgroup at smc.vnet.net
  • Subject: [mg90557] Re: [mg90498] Defining Functions and Simplifying Solutions
  • From: Sseziwa Mukasa <mukasa at jeol.com>
  • Date: Sat, 12 Jul 2008 05:35:46 -0400 (EDT)
  • References: <200807110602.CAA03726@smc.vnet.net>

On Jul 11, 2008, at 2:02 AM, Locus wrote:

> Hello!
>
> I actually have to questions:
>
> 1. Is there a more handy way to define/use functions as compared to  
> the following way (which works, but is complicated always typing  
> the variable definitions):
>
> G[\[Alpha]1_Real, \[Alpha]2_Real, e1_Real,
>   e2_Real] = \[Alpha]1*e1 + \[Alpha]2*e2
>
> v[G_Real] = a*G[\[Alpha]1, \[Alpha]2, e1, e2] + b

I'm not sure what you mean, using greek characters for variables can  
be laborious, do you really need to?  The fastest way to type alpha  
is Esc a Esc so you save five keystrokes per alpha there (look up  
entering Greek letters in the help guide).

Also why are you using = instead of :=?

> 2. After several steps, I receive the following solution
>
> {{a -> (0. (e1 \[Beta]1 + e2 \[Beta]2 \[Lambda]))/(rA \[Tau]^2)}}
>
> which obviously equals zero. How can I 'force' Mathematica to  
> display only 0 as result and not such a unnessecarily complicated  
> expression? FullSimplify does not work here.

The problem with Simplification is that 0. is a machine precision  
number, if you replace it with 0 you get your desired result:

In[10]:= Simplify[(0 (e1 \[Beta]1+e2 \[Beta]2 \[Lambda]))/(rA \[Tau]^2)]
Out[10]= 0

Regards,

Ssezi



  • Prev by Date: Re: Question about diference between Animate and Manipulate
  • Next by Date: Re: Defining Functions and Simplifying Solutions
  • Previous by thread: Defining Functions and Simplifying Solutions
  • Next by thread: Re: Defining Functions and Simplifying Solutions