RE: Simple Eval Question
- To: mathgroup at smc.vnet.net
- Subject: [mg31953] RE: [mg31883] Simple Eval Question
- From: "Higinio Ramos" <higra at usal.es>
- Date: Fri, 14 Dec 2001 04:21:15 -0500 (EST)
- References: <200112091107.GAA18114@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
----- Original Message -----
From: ivo welch <ivo.welch at anderson.ucla.edu>
To: mathgroup at smc.vnet.net
Subject: [mg31953] [mg31883] Simple Eval Question
> I have a simple problem. I want to numerically solve
>
> Solve[ Integrate[ f[x,p]*g[x], {x,0,Infinity}] == V , p ]
>
> where f[] and g[] are defined functions, but the naive solution fails.
>
> W=1; g=0.5; q=0.1; V=2;
> fd[x_]:= PDF[ LogNormalDistribution[0,1],x ] ;
> Solve[ Integrate[ ((W +(x-p)*q)^g)/g * fd[x], { x, 0, Infinity } ]== V,
p ]
>
> Solve::"tdep": "The equations appear to involve the variables to be solved
\
> for in an essentially non-algebraic way."
>
> The correct answer seems to be 1.5652 . How do I ask Mathematica to tell
me
> this number?
>
> (My ultimate goal is to plot the solved p as a function of q.)
>
> /iaw
>
W = 1; g = 0.5; q = 0.1; V = 2;
fd[x_] := PDF[ LogNormalDistribution[0, 1], x ] ;
In[13]:=
SetPrecision[
dRoot[
Integrate[ ((W + (x - p)*q)^g)/g * fd[x], { x, 0, Infinity } ] == V, {p,
1.5} ], 20]
Out[13]=
{p -> 1.5652055223965051223}
H. Ramos
- References:
- Simple Eval Question
- From: ivo.welch@anderson.ucla.edu (ivo welch)
- Simple Eval Question