Commit Graph

7 Commits

Author SHA1 Message Date
Laurence Withers ca4b3beb5a Test program usability fixes 2011-04-15 19:10:21 +00:00
Laurence Withers e0046bfb84 Add ability to compute filter response
Adds functionality to compute the response of the filter's transfer function at
a given frequency. This uses the Z domain transform. A new test program
zplot_filter (which is compatible with the existing plot_filter) is provided.
2011-04-15 18:56:19 +00:00
Laurence Withers 4c0680fb02 iir_parse_n(): fix silly bug
Fixed a silly bug that caused iir_parse_n() to fail for n>1.
2011-04-15 18:05:37 +00:00
Laurence Withers bc383a92da iir_filter_copy(): don't copy uninitialised state
If iir_filter_copy() was called on a filter which had no state, it would copy
the uninitialised memory from that filter. Check for this.
2011-04-15 17:56:48 +00:00
Laurence Withers 9a87889dd3 Improve initial conditions
Compute the DC gain of the filter (assuming 0 if unstable) and use that to
set the initial conditions of a filter as follows:
  x(t<0)=x(0)
  y(t<0)=x(0) × dc_gain
2011-04-15 17:53:44 +00:00
Laurence Withers 2031d084cc Bump version 2010-11-08 15:18:39 +00:00
Laurence Withers ce36ca9ef5 Import initial work 2010-11-08 15:18:07 +00:00