rework iir filter

CHANGELOG.md

@@ -10,6 +10,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 * `hbf` FIRs, symmetric FIRs, half band filters, HBF decimators and interpolators
+* `iir::PidBuilder` a builder for PID coefficients
+* `iir::Biquad::{hold, proportional, identity}`
+
+### Removed
+
+* `iir::Vec5` type alias has been removed.
+
+### Changed
+
+* `iir`: The biquad IIR filter API has been reworked. `IIR -> Biquad` renamed.
 
 ## [0.10.0](https://github.com/quartiq/idsp/compare/v0.9.2..v0.10.0) - 2023-07-20
 

benches/micro.rs

@@ -62,20 +62,20 @@ fn iir_int_bench() {
 }
 
 fn iir_f32_bench() {
-    let dut = iir::IIR::<f32>::default();
-    let mut xy = iir::Vec5::default();
+    let dut = iir::Biquad::<f32>::default();
+    let mut xy = [0.0; 5];
     println!(
         "int::IIR::<f32>::update(s, x): {}",
-        bench_env(0.32241, |x| dut.update(&mut xy, *x, true))
+        bench_env(0.32241, |x| dut.update(&mut xy, *x))
     );
 }
 
 fn iir_f64_bench() {
-    let dut = iir::IIR::<f64>::default();
-    let mut xy = iir::Vec5::default();
+    let dut = iir::Biquad::<f64>::default();
+    let mut xy = [0.0; 5];
     println!(
         "int::IIR::<f64>::update(s, x): {}",
-        bench_env(0.32241, |x| dut.update(&mut xy, *x, true))
+        bench_env(0.32241, |x| dut.update(&mut xy, *x))
     );
 }
 

src/complex.rs

@@ -20,8 +20,8 @@ impl ComplexExt<i32, u32> for Complex<i32> {
     /// ```
     /// use idsp::{Complex, ComplexExt};
     /// Complex::<i32>::from_angle(0);
-    /// Complex::<i32>::from_angle(1 << 30);  // pi/2
-    /// Complex::<i32>::from_angle(-1 << 30);  // -pi/2
+    /// Complex::<i32>::from_angle(1 << 30); // pi/2
+    /// Complex::<i32>::from_angle(-1 << 30); // -pi/2
     /// ```
     fn from_angle(angle: i32) -> Self {
         let (c, s) = cossin(angle);