MathGroup Archive 2006

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

Search the Archive

Re: Simple question from a biologist


tnad wrote:
> I'm a bit new to this so please bear with me. I solved this eqation:
> 
> Sol = Solve[{{{-x, 0, z}, {x, -y, 0}, {0, y, -z}}.{A, B, C} == 0, A + B + C == 1}, {A, B, C}]
> 
> and got the ouputs of A, B and C interms of x,y, and z each.
> 
> Now I want to express a term called "rate" where rate = Ax = By = Cz in terms of x, y and Z only.
> 
> So I tried to do this:
> Solve[rate == Ax , rate] /. Sol
> 
> but I cannot get the rate in terms of x,y and z.
> Is there a better way to do this? Also if someone knows of a better tuttorial (better than the built-in tuttorial) for mathematica, please let me know.
> 
Do you mean something like Out[2]?

In[1]:=
sol = Solve[{{{-x, 0, z}, {x, -y, 0}, {0, y, -z}} . {A, B, C} == 0,
     A + B + C == 1}, {A, B, C}]

Out[1]=
              y z                   x z
{{A -> ---------------, B -> ---------------,
        x y + x z + y z       x y + x z + y z

               x y
    C -> ---------------}}
         x y + x z + y z

In[2]:=
Solve[rate == A*x, rate] /. sol[[1]]

Out[2]=
                x y z
{{rate -> ---------------}}
           x y + x z + y z


HTH,
Jean-Marc


  • Prev by Date: Re: Simple question from a biologist
  • Next by Date: Re: Selecting Real Roots, Again
  • Previous by thread: Re: Simple question from a biologist
  • Next by thread: Re: Simple question from a biologist