Jeffrey Cunningham wrote: > On Thu, 29 Sep 2011 10:56:24 -0700, Robert T. Short > <oct...@phaselockedsystems.com> wrote: > > >> >> Alex, >> >> This is simply an artifact of the conformal mapping from the >> continuous-time domain to the discrete-time domain. Remember that a >> continuous-time Butterworth filter has infinite attenuation at infinite >> frequency, and the frequencies at infinity are mapped to the Nyquist >> edges. >> >> Just as an aside, there is no real reason to test for attenuation or >> other filter response characteristics. If the filter routine works and >> the coefficients are correct, then the final filter will work just >> fine. I am not saying, of course, that you shouldn't build tests like >> this, but it is somewhat overkill. >> >> Bob >> >> > One never knows if it is implemented correctly without the tests, no? I > personally like to bundle tests with codes because I've found odd things > sometimes happen when they get ported from one architecture to another > that they help flush out quickly. Another good thing about them is they > quickly show how to use the function properly. > > Jeff > >
Well, I didn't say you shouldn't do it, but what are you testing? Unless the forge function (that I have never used) is different than MATLAB, butter returns the coefficients and you use filter to do the work. So if you are testing butter, then all you need to test is whether the coefficients are correct. The filter routine already has tests (although I am sure that more could be added). Testing, like design, should be modularized whenever possible. Oh well, 'nuff said. The real information in the email was addressing Alex' concerns about attenuation at higher frequencies. Bob ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2dcopy1 _______________________________________________ Octave-dev mailing list Octave-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/octave-dev
