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

Re: How to evaluate the Laplacian of a function as a function?

• To: mathgroup at smc.vnet.net
• Subject: [mg114357] Re: How to evaluate the Laplacian of a function as a function?
• From: "Kevin J. McCann" <Kevin.McCann at umbc.edu>
• Date: Thu, 2 Dec 2010 05:38:17 -0500 (EST)
• References: <id4sma$ci5$1@smc.vnet.net>

Try using this

funcLap1[Xx_,Yy_]=Laplacian[func[Xx,Yy]]

I would use the equals rather than the delayed equals (:=)

Also, you can make your coordinates "nice" by doing a

SetCoordinates[Cartesian[x,y,z]]

beforehand. Then you can use x,y,z rather than Xx,Yy,Zz, which are the 
matematica defaults.

Kevin

On 12/1/2010 2:15 AM, Iliyan Georgiev wrote:
> Hi,
>
> I have a stupid problem and cannot find a solution anywhere. I have
> the function
>
> func[x_,y_] := 3/Pi*(1 - x^2 + y^2))^2
>
> which I need the Laplacian of:
>
> funcLapl := Laplacian[func[Xx,Yy]]
>
> The Laplacian is computed correctly, but how can I treat the result as
> a function? I want to be able to evaluate/plot the Laplacian. I tried
> many things and I'm frustrated. My current solution is to manually
> copy the derived Laplacian and create a function from that. It's
> obviously not a good solution.
>
> Any suggestions?
>