Thanks for the reply. No i dont use it, since what i need is how to extract/filter the daily data having frequency 1/16 day. is it possible to only use bandpass filter?<div><br></div><div><br></div><div><br><br>On Tuesday, 6 October 2015, Dennis Shea <<a href="mailto:shea@ucar.edu">shea@ucar.edu</a>> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Are you looking a 'complex demodulation" ???<br>
<br>
If so, that is in the 6.3.1 release:<br>
<a href="http://www.ncl.ucar.edu/future_release.shtml" target="_blank">http://www.ncl.ucar.edu/future_release.shtml</a><br>
<br>
Click 'demod_cmplx' =><br>
<a href="http://www.ncl.ucar.edu/Document/Functions/Contributed/demod_cmplx.shtml" target="_blank">http://www.ncl.ucar.edu/Document/Functions/Contributed/demod_cmplx.shtml</a><br>
<br>
See Examples at the bottom of <a href="http://www.ncl.ucar.edu/Applications/spec.shtml" target="_blank">http://www.ncl.ucar.edu/Applications/spec.shtml</a><br>
<br>
<br>
On Mon, Oct 5, 2015 at 4:32 PM, Xi Chang <<a href="javascript:;" onclick="_e(event, 'cvml', 'xi.chang01@gmail.com')">xi.chang01@gmail.com</a>> wrote:<br>
> Hi NCL,<br>
><br>
> I have daily data 10 years. I'd like to filter the data at frequency (1/16)<br>
> day. To do so what the most appropiate frquency ranges that i have to use<br>
> ?, is it domething like fa=1/15 and fb=1/17 ?<br>
> I aware if the band is too narrow the filtered signals are fake /artificial<br>
> (i tesed with ncl butterwooth and the filtered results are weird) ? is there<br>
> any idea how to do that appropriately? do i need to use hourly data instead<br>
> of daily?<br>
><br>
> Thanks<br>
><br>
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><br>
</blockquote></div>