Re: How to perform the 1-D signal filter?

On 2=D4=C21=C8=D5, =CF=C2=CE=E710=CA=B158=B7=D6, "Kenneth P. Bowman"
<k-bow.=
...@[EMAIL PROTECTED]
> wrote:
> In article
> <e9b5822c-2240-4937-ad85-a53f057d9...@[EMAIL PROTECTED]
>,
>
>
>
>  "dux...@[EMAIL PROTECTED]
" <dux...@[EMAIL PROTECTED]
> wrote:
> > Dear all,
>
> > Here I give a signal example and hope somone can show me how to
> > perferm the frequency filter on it.
>
> > ;creat a signal data with two peaks in frequency domain at 2 and 3 Hz.
> > t=3Dfindgen(1000)/10.
> > data=3Dsin(2*!pi*2*t)+sin(2*!pi*3*t)
>
> > freq=3Dfindgen(501)/100.
> > v=3Dfft(data)
> > plot,freq,abs(v[0:500])^2,xtitle=3D'frequency',ytitle=3D'spectrum'
>
> > I want to filter the signal with the frequency higher than 2.5 Hz. How
> > do I do this?
>
> > I have read the help files about Digital_Filter and Convol, but I do
> > not know how to select the parameters for Signal_Filter.
>
> > Du
>
> You could look at the chapter on FFTs and digital filtering in my IDL
> book (http://idl.tamu.edu).
 I wrote the chapter in part so that *I*
> could refer to it whenever I need to do a digital filter.  :-)
>
> Ken Bowman

It is a pity that I cannot buy your book in my country.

Du