> I am trying to filter out the Low-frequency signal and
> using "wgt_runave" to compute this with lancos weights
> But the result seem has exhibits artifical oscillation.
>
> if anyone can tell me how to filter out it in using NCL
> build-in function or has any other method for the High-pass filter
By Lancos weights, I assume you mean something like:
nwt = 9
fca = 0.25
ihp = 1 ; high pass
nsigma = 1.
wgt = filwgts_lancos (nwt, ihp, fca, -999., nsigma)
Then applying these weights via wgt_runave:
yhigh = wgt_runave(y , wgt, 0 )
-------------------------------------------
Did you plot the response function of the filter?
The required information is returned as attributes
of wgt: wgt@freq and wgt@resp
wks = gsn_open_wks ("x11","high_pass_filter")
res = True
res@tiMainString = "ihp="+ihp+" fca="+fca+" nwt="+nwt
plot = gsn_csm_xy (wks,wgt@freq, wgt@resp,res)
-------------------------------------------
_______________________________________________
ncl-talk mailing list
ncl-talk@ucar.edu
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
This archive was generated by hypermail 2b29 : Tue Aug 09 2005 - 12:17:54 MDT