comp.lang.idl-pvwave archive - RDF feed
type: channel
description: Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
items: Re: FFT and CONVOL

Re: FFT and CONVOL
type: item
description: In article 68A97CA3@crml.uab.edu, Isabelle Banville <ib@crml.uab.edu> writes: > WAVE> filter_param=DIGITAL_FILTER(0.0,1.0,50,10) > WAVE> filtered_signal=CONVOL(data(*,0,0),filter_param) > WAVE> PLOT,data(*,0,0) > WAVE> PLOT,filtered_signal(*,0,0) > So this works fine, but as you notice, flow is set at 0 and fhigh is set at > 1. > As soon as I change either one of these values (even a hair, 0.001) there is > no more signal. I refuse to believe that my signal can not tolerate any > filter! > data is an INTARR. I have tried converting to floats with no change. Your code looks plausible and works fine when I use it with different flow's. Using data as INTs is definitely dangerous and bound to lead to tears. Don't do this - IDL routines tend to take your datatypes on trust and not convert them which leads to hideous problems is you hand int's to routines that want floats. I suspect that this is your problem. - William --- William M Connolley | wmc@bas.ac.uk | http://www.nbs.ac.uk/public/icd/wmc/ Climate Modeller, British Antarctic Survey | Disclaimer: I speak for myself
creator: wmc
date: 1998-06-04T07:00:00-00:00