From fba482b5545a6c02bf32d9dc4f261f6fc5556064 Mon Sep 17 00:00:00 2001
From: Justin Worthe <justin.worthe@gmail.com>
Date: Sat, 26 Nov 2016 09:42:25 +0200
Subject: Updated name of crate everywhere

---
 src/audio.rs      |  6 ++--
 src/main.rs       |  4 +--
 src/transforms.rs | 86 +++++++++++++++++++++++++++++++++++++++++--------------
 3 files changed, 71 insertions(+), 25 deletions(-)

(limited to 'src')

diff --git a/src/audio.rs b/src/audio.rs
index e418e94..bcee400 100644
--- a/src/audio.rs
+++ b/src/audio.rs
@@ -24,7 +24,8 @@ pub fn get_device_list(pa: &pa::PortAudio) -> Result<Vec<(u32, String)>, pa::Err
     Ok(list)
 }
 
-//#[test]
+#[test]
+#[ignore]
 fn get_device_list_returns_devices() {
     let pa = init().expect("Could not init portaudio");
     let devices = get_device_list(&pa).expect("Getting devices had an error");
@@ -61,7 +62,8 @@ pub fn start_listening(pa: &pa::PortAudio, device_index: u32,
     Ok(stream)
 }
 
-//#[test]
+#[test]
+#[ignore]
 fn start_listening_returns_successfully() {
     let pa = init().expect("Could not init portaudio");
     let devices = get_device_list(&pa).expect("Getting devices had an error");
diff --git a/src/main.rs b/src/main.rs
index 0eea7f3..91befca 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,6 @@
-extern crate musician_training;
+extern crate rusty_microphone;
 
-use musician_training::*;
+use rusty_microphone::*;
 
 fn main() {
     let gui_result = gui::start_gui();
diff --git a/src/transforms.rs b/src/transforms.rs
index 371379d..4d0e224 100644
--- a/src/transforms.rs
+++ b/src/transforms.rs
@@ -7,10 +7,18 @@ pub struct FrequencyBucket {
     pub intensity: f64
 }
 
+impl FrequencyBucket {
+    pub fn ave_freq(&self) -> f64 {
+        (self.min_freq + self.max_freq) / 2.0
+    }
+}
+
 pub fn fft(input: Vec<f64>, sample_rate: f64) -> Vec<FrequencyBucket> {
     let frames = input.len();
+    let mean_input = input.iter().sum::<f64>()/input.len() as f64;
+    
+    let mut intensities = input.iter().map(|x|x-mean_input).collect::<Vec<_>>();
     let plan = dft::Plan::new(dft::Operation::Forward, frames);
-    let mut intensities = input.clone();
     dft::transform(&mut intensities, &plan);
 
     let frequency_resolution = sample_rate / 2.0 / frames as f64;
@@ -28,35 +36,71 @@ pub fn fft(input: Vec<f64>, sample_rate: f64) -> Vec<FrequencyBucket> {
 pub fn find_fundamental_frequency(frequency_domain: &Vec<FrequencyBucket>) -> Option<f64> {
     //TODO look at all significant frequencies, find fundamental
     //TODO return None is none of them are significant
+    let positive_buckets = frequency_domain.iter().filter(|x| x.intensity > 0.0).cloned().collect::<Vec<_>>();
+    let average_intensity = positive_buckets.iter().map(|x| x.intensity).sum::<f64>() / frequency_domain.len() as f64;
+    let significant_buckets = positive_buckets.iter().filter(|x| x.intensity > average_intensity).cloned().collect::<Vec<_>>();
+    for bucket in significant_buckets.iter() {
+        //println!("{:?}", bucket);
+    }
     
-    let max_frequency = frequency_domain.iter()
+    let max_bucket = significant_buckets.iter()
         .fold(None as Option<::transforms::FrequencyBucket>, |max, next|
               if max.is_none() || max.clone().unwrap().intensity < next.intensity { Some(next.clone()) } else { max }
-        ).unwrap().max_freq;
-    
-    Some(max_frequency)
+        ).unwrap();
+
+    Some(max_bucket.ave_freq())
 }
 
-#[test]
-fn fft_on_sine_wave() {
-    use std::f64::consts;
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::f64::consts::PI;
     
-    let sample_rate = 44100.0 as f64;
-    let amplitude = 1.0 as f64;
-    let frames = 16384;
-    let frequency = 10000.0 as f64; //10KHz
-    let frequency_resolution = sample_rate / 2.0 / frames as f64;
+    const SAMPLE_RATE: f64 = 44100.0;
+    const FRAMES: usize = 512;
+
+    fn frequency_resolution() -> f64 {
+        SAMPLE_RATE / 2.0 / FRAMES as f64
+    }
+
+    fn sin_arg(f: f64, t: f64, phase: f64) -> f64 {
+        2.0 as f64 * PI * f * t + phase
+    }
+
+    fn sample_sinusoud(amplitude: f64, frequency: f64, phase: f64) -> Vec<f64> {
+        (0..FRAMES)
+            .map(|x| {
+                let t = x as f64 / SAMPLE_RATE;
+                sin_arg(frequency, t, phase).sin() * amplitude
+            }).collect()
+    }
     
-    let samples = (0..frames)
-        .map(|x| {
-            let t = x as f64 / sample_rate;
-            (2.0 as f64 * consts::PI * frequency * t).sin() * amplitude
-        }).collect();
+    #[test]
+    fn fft_on_sine_wave() {
+        let frequency = 10000.0 as f64; //10KHz
+        
+        let samples = sample_sinusoud(1.0, frequency, 0.0);
+        let frequency_domain = fft(samples, SAMPLE_RATE);
+        let fundamental = find_fundamental_frequency(&frequency_domain).unwrap();
+
+        assert!((fundamental-frequency).abs() < frequency_resolution(), "expected={}, actual={}", frequency, fundamental);
+    }
 
-    let result = fft(samples, sample_rate);
-    let fundamental = find_fundamental_frequency(&result);
+    #[test]
+    fn fft_on_two_sine_waves() {
+        let samples1k = sample_sinusoud(0.5, 1000.0, 0.0);
+        let samples2k = sample_sinusoud(1.0, 10000.0, 0.0);
+        let expected_fundamental = 1000.0;
+        
+        let samples = samples1k.iter().zip(samples2k.iter())
+            .map(|(a, b)| a+b)
+            .collect();
+        let frequency_domain = fft(samples, SAMPLE_RATE);
+        
+        let fundamental = find_fundamental_frequency(&frequency_domain).unwrap();
 
-    assert!((fundamental-frequency).abs() < frequency_resolution, "expected={}, actual={}", frequency, fundamental);
+        assert!((fundamental-expected_fundamental).abs() < frequency_resolution(), "expected_fundamental={}, actual={}", expected_fundamental, fundamental);
+    }
 }
 
 pub fn hz_to_pitch(hz: f64) -> String {
-- 
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