Correct goniometer transport and correlation meter

src/correlation.rs

@@ -27,7 +27,7 @@ impl CorrelationMeter {
             power_r: 0.0,
             cross_power: 0.0,
             value: 0.0,
-            negative_peak: 1.0,
+            negative_peak: 0.0,
             reset_token,
         };
         meter.configure(sample_rate, response_seconds, reset_token);
@@ -40,12 +40,12 @@ impl CorrelationMeter {
         if self.sample_rate != sample_rate || self.response_seconds != response_seconds {
             self.sample_rate = sample_rate;
             self.response_seconds = response_seconds;
-            self.alpha = 1.0
-                - (-1.0 / (f64::from(sample_rate) * f64::from(response_seconds))).exp();
+            self.alpha =
+                1.0 - (-1.0 / (f64::from(sample_rate) * f64::from(response_seconds))).exp();
         }
         if self.reset_token != reset_token {
             self.reset_token = reset_token;
-            self.negative_peak = 1.0;
+            self.negative_peak = 0.0;
         }
     }
 
@@ -106,13 +106,21 @@ mod tests {
     fn detects_positive_negative_and_quadrature_signals() {
         let sample_rate = 48_000;
         let phase_step = 2.0 * std::f32::consts::PI * 1_000.0 / sample_rate as f32;
-        for (phase, expected) in [(0.0, 1.0), (std::f32::consts::PI, -1.0), (std::f32::consts::FRAC_PI_2, 0.0)] {
+        for (phase, expected) in [
+            (0.0, 1.0),
+            (std::f32::consts::PI, -1.0),
+            (std::f32::consts::FRAC_PI_2, 0.0),
+        ] {
             let mut meter = CorrelationMeter::new(sample_rate, 1.0, 0);
             run_signal(&mut meter, 5, |index| {
                 let angle = phase_step * index as f32;
                 (angle.sin(), (angle + phase).sin())
             });
-            assert!((meter.value() - expected).abs() < 0.002, "phase {phase}: {}", meter.value());
+            assert!(
+                (meter.value() - expected).abs() < 0.002,
+                "phase {phase}: {}",
+                meter.value()
+            );
         }
     }
 
@@ -134,7 +142,7 @@ mod tests {
         });
         assert!(fast.negative_peak() < -0.7);
         fast.configure(sample_rate, 1.0, 1);
-        assert_eq!(fast.negative_peak(), 1.0);
+        assert_eq!(fast.negative_peak(), 0.0);
     }
 
     #[test]
@@ -142,6 +150,7 @@ mod tests {
         let mut meter = CorrelationMeter::new(48_000, 1.0, 0);
         run_signal(&mut meter, 2, |_| (0.0, 0.0));
         assert_eq!(meter.value(), 0.0);
+        assert_eq!(meter.negative_peak(), 0.0);
         run_signal(&mut meter, 2, |index| {
             let sample = if index & 1 == 0 { 0.5 } else { -0.5 };
             (sample, 0.0)