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Re: Anti-Chop Function

• To: mathgroup at smc.vnet.net
• Subject: [mg5828] Re: [mg5813] Anti-Chop Function
• From: Edward Neuman <edneuman at math.siu.edu>
• Date: Thu, 23 Jan 1997 03:19:31 -0500
• Sender: owner-wri-mathgroup at wolfram.com

At 12:44 AM 1/22/97 -0500, you wrote:
>The Chop[Data, Min] sets all values in Data that are < Min equal to 0.  Is 
>there an equivalent function that will take all values in Data that are > 
>Max and set them equal to 0?  I'm trying to eliminate the DC components 
>of a Fourier transform, and the only way I've been able to do it to date 
>is buy manually Delete[]-ing the first value and Insert[] -ing 0.
>
>
>Mat
>---
>Mathew Jason Binkley - Astronomy TA  | "It was the dawn of the Third Age 
>Wake Forest University - Olin 304    |  of mankind, the year the Great
>Phone: (910) 759-4957                |  War came upon us all."
>WWW:   http://www.wfu.edu/~binklmj5/ |  - John Sheridan, Babylon 5
>
>
>

Mathew;

The "Anti-Chop Function," named here f, uses a pattern matching
transformation rule:


 In[1]:=
 Clear[f]

 In[2]:=
 f[mylist_,mymax_]:=mylist//.{a___,b_,c___}/;Abs[b]>=mymax:>{a,0,c}

 In[3]:=
 mymax=1.0;
 mylist={-1.5,-0.5,0.5,3.0};

 In[4]:=
 f[mylist,mymax]

 Out[4]=
 {0,-0.5,0.5,0}

 I hope this does a job.

 Edward

 
===========================================================
Edward Neuman                 Phone: (618) 453-6501
Department of Mathematics      Fax:   (618) 453-5300
Southern Illinois University  E-mail:edneuman at math.siu.edu
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WWW: http://www.science.siu.edu/mathematics/neuman/