2011/10/12 Rudy Eschauzier <reschauz...@yahoo.com>: > Hi Carnë, > > Looking into it some more, I found that even setting small values in the > output polynomials to zero is an error. We need to remove lines like this: > > b_out(abs(b_out)<tol) = 0; > a_out(abs(a_out)<tol) = 0; > > The reason is that the tolerance applies to the positions of the poles, but > not necessarily to the coefficients of the z and s-domain polynomials. This > becomes a problem for relatively high sample rates in impinvar() and low > sample rates in invimpinvar(). > > As an example, take > > octave:1> [b a]=impinvar([1], [1, 2, 1], 100) > b = > > 0 0 > > a = > > 1.00000 -1.98010 0.98020 > > Note how the coefficients of b are rounded to zero. > > The correct result, taking out the offending lines, is > > octave:1> [b a]=impinvar([1], [1, 2, 1], 100) > b = > > 0.0000e+00 9.9005e-05 > > a = > > 1.00000 -1.98010 0.98020 > > which is also what Matlab gives. > > Attached are the updated files, along with a patch file to the current svn > revision. I have also updated the test cases to catch these type of issues > in the future. > > Thanks, > Rudy.
Hi everyone, I just made the changes and committed. Thank you for keep checking on this, Carnë ------------------------------------------------------------------------------ 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-d2d-oct _______________________________________________ Octave-dev mailing list Octave-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/octave-dev
