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

MathGroup Archive 2008

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

Search the Archive

Re: Log(ln) Function + 2 Parameters + Greater

  • To: mathgroup at smc.vnet.net
  • Subject: [mg89298] Re: Log(ln) Function + 2 Parameters + Greater
  • From: Jerry <Jer75811 at yahoo.com>
  • Date: Wed, 4 Jun 2008 05:37:38 -0400 (EDT)
  • References: <g22tp5$ikl$1@smc.vnet.net> <g237c4$q2n$1@smc.vnet.net>

Sir, I have never seen a function definition in the form you 
give:
f[a_][x_] := x (a + Log[x])^2

After a bit of playing with it, I don't see the difference 
between this and

f[a_,x_] := x (a + Log[x])^2

I really don't know how to search in help for this f[a_][x_] 
form. Can you tell me if there is any essential difference?

Thank you.


David Park wrote:
> First, define your f function with a as a parameter.
> 
> f[a_][x_] := x (a + Log[x])^2
> 
> Mathematica can't make a plot unless it knows values for a. Of course, it 
> won't plot any results for x < 0 and I'm not certain if you actually meant x 
>  > 0 rather than a > 0. In any case, you can use any real domain for a. Here 
> is a plot for a specific value of a.
> 
> Plot[f[2][x], {x, -5, 5},
>  AxesLabel -> {x, f}]
> 
> You can look at an extended a domain by using Plot3D.
> 
> Plot3D[f[a][x], {a, -5, 5}, {x, 0, 5},
>  PlotRange -> All,
>  AxesLabel -> {a, x, f}]
> 
> Another approach is to use a Manipulate statement with a controlled by a 
> slider.
> 
> Manipulate[
>  Plot[f[a][x], {x, 0, 5},
>   PlotRange -> {0, 250},
>   AxesLabel -> {x, f}],
>  Style[Row[{HoldForm[f["a"][x]] == f["a"][x]}], 16],
>  Delimiter,
>  {a, -5, 5, Appearance -> "Labeled"}]
> 
> 
> 


  • Prev by Date: Re: Log(ln) Function + 2 Parameters + Greater
  • Next by Date: Re: SetOptions[TableForm] doesn't seem to work?
  • Previous by thread: Re: Log(ln) Function + 2 Parameters + Greater
  • Next by thread: Re: Re: Log(ln) Function + 2 Parameters + Greater