From 2d9a5a5bfb4981c7abb05585e52df2ce198f624a Mon Sep 17 00:00:00 2001
From: Matt McPherrin <git@mcpherrin.ca>
Date: Thu, 16 Jul 2015 15:57:23 -0700
Subject: [PATCH] Change sample_rate to u32 -- float doesn't make sense there
---
README.md | 5 +++--
src/lib.rs | 10 +++++-----
2 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/README.md b/README.md
index f837e12..e1ae2d5 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,6 @@
Goertzel
--------
-The Goertzel Algoritm is a simplified discrete fourier transform, useful for
-tone detection.
+The Goertzel Algoritm is a single-bin discrete fourier transform, useful for
+tone detection with a small number of tones. This has not yet been extensively
+tested, but appears to basically work.
diff --git a/src/lib.rs b/src/lib.rs
index 5afbd29..1fec395 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -22,8 +22,8 @@ pub struct Partial {
}
impl Parameters {
- pub fn new(target_freq: f32, sample_rate: f32, window_size: usize) -> Self {
- let k = target_freq * (window_size as f32) / sample_rate;
+ pub fn new(target_freq: f32, sample_rate: u32, window_size: usize) -> Self {
+ let k = target_freq * (window_size as f32) / (sample_rate as f32);
let omega = (f32::consts::PI * 2. * k) / (window_size as f32);
let cosine = omega.cos();
Parameters {
@@ -64,7 +64,7 @@ impl Partial {
#[test]
fn zero_data() {
- let p = Parameters::new(1800., 8000., 256);
+ let p = Parameters::new(1800., 8000, 256);
assert!(p.start().add(&[0; 256]).finish_mag() == 0.);
assert!(p.start().add(&[0; 128]).add(&[0;128]).finish_mag() == 0.);
}
@@ -80,10 +80,10 @@ fn sine() {
buf[sample] = ((time * freq * 2. * PI).sin()*std::i16::MAX as f32) as i16;
}
- let p = Parameters::new(freq, 8000., 8000);
+ let p = Parameters::new(freq, 8000, 8000);
let mag = p.start().add(&buf[..]).finish_mag();
for testfreq in (0 .. 30).map(|x| (x * 100) as f32) {
- let p = Parameters::new(testfreq, 8000., 8000);
+ let p = Parameters::new(testfreq, 8000, 8000);
let testmag = p.start().add(&buf[..]).finish_mag();
println!("{:4}: {:12.3}", testfreq, testmag);
if (freq-testfreq).abs() > 100. {
--
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