Commit Graph

20 Commits

Author SHA1 Message Date
Laurence Withers 1cf13be442 Update copyright dates 2014-07-07 11:10:28 +00:00
Laurence Withers 2ceb582a30 Move doxygen docs into subsection for partioning 2014-07-07 11:07:05 +00:00
Laurence Withers 8a763c4bf3 Bump C library minor soversion 2014-07-07 11:03:30 +00:00
Laurence Withers 197446db5f Add iir_coeff_copy() 2014-07-07 09:56:28 +00:00
Laurence Withers a57e239d10 Mark array parameters to iir_coeff_new() as const 2014-07-07 09:46:23 +00:00
Laurence Withers 628e1d55a2 Add coefficient query functions
Add some functions that allow the opaque struct iir_coeff_t to be queried
in order to retrieve the number and value of the filter coefficients.
2014-07-05 11:12:42 +00:00
Laurence Withers 77a526388d Add C++ include guards 2014-07-05 11:05:34 +00:00
Laurence Withers 7dc73bee8a Bump version 2012-03-16 10:56:19 +00:00
Laurence Withers 26456a3080 Butterworth: use 2nd order components
When building a high-order Butterworth filter, split into 2nd-order
components, not 4th-order. Instability due to quantization effects has been
observed on real data even with double-precision floating point.
2012-03-16 10:55:21 +00:00
Laurence Withers 00b6427cca Build system update: ignore script file 2012-03-16 10:55:18 +00:00
Laurence Withers 6207c12f14 Bump version 2011-04-15 19:12:32 +00:00
Laurence Withers e9f55c89ee Bump version 2011-04-15 19:12:32 +00:00
Laurence Withers 80f79655ca Copyright/editor line updates 2011-04-15 19:12:04 +00:00
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