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Re: FourierTransform

• To: mathgroup at smc.vnet.net
• Subject: [mg52528] Re: [mg52517] FourierTransform
• From: yehuda ben-shimol <benshimo at bgu.ac.il>
• Date: Wed, 1 Dec 2004 05:57:44 -0500 (EST)
• References: <200411301024.FAA01399@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

You do not have to give up your classroom demos.
Adding some properties to a built-in function is easy.
Try
Unprotect[FourierTransform];
FourierTransform[f_'[x_], x_, k_] := -\[ImaginaryI] k 
FourierTransform[f[x], x, k];
Protect[FourierTransform]
yehuda
Dr A.H. Harker wrote:

>In Version 4 Mathematica was smart enough to know that
>
>FourierTransform[f'[x], x, k]
>
>should give
>
>-\[ImaginaryI] k FourierTransform[f[x], x, k].
>
> Version 5 seems no longer to do this -- a nice classroom demonstration and
>a valuable method of solving differential equations down in flames.  
>
>  Why is this?
>
>
> Tony Harker (Dr A.H. Harker)
> Deputy Head of Department
> Deputy Head, Condensed Matter and Materials Physics Group
> Department of Physics and Astronomy
> University College London
> Gower Street
> LONDON
> WC1E  6BT
> (44)(0)207 679 3404
> a.harker at ucl.ac.uk
>
>
>
>  
>