diff options
author | Justin Worthe <justin.worthe@gmail.com> | 2016-12-03 21:56:26 +0200 |
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committer | Justin Worthe <justin.worthe@gmail.com> | 2016-12-03 21:56:26 +0200 |
commit | 885618f96ab1079ee49553f46804d2a4460e41b3 (patch) | |
tree | dd2d29524ccd473a47e918a6e15a80fb8896da9a /src/sinusoid.rs | |
parent | 4e55f98cac43a71f6a83aa9d81b1cb26c1745e55 (diff) |
Started adding sinusoids
Diffstat (limited to 'src/sinusoid.rs')
-rw-r--r-- | src/sinusoid.rs | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/src/sinusoid.rs b/src/sinusoid.rs new file mode 100644 index 0000000..6ee5019 --- /dev/null +++ b/src/sinusoid.rs @@ -0,0 +1,63 @@ +use std; +use std::ops::{Add, Sub, Mul, Div, Neg}; +use ::num_traits::{Trig, Pow, Float}; + +// generic number type, but realistically it's only useful for +// floats. Maybe also complex<float> + +pub struct Sinusoid<T> { + amplitude: T, + frequency: T, + phase: T +} + +impl<T> Sinusoid<T> { + pub fn new(amplitude:T, frequency: T, phase: T) -> Sinusoid<T> { + Sinusoid { + amplitude: amplitude, + frequency: frequency, + phase: phase + } + } +} +impl<T> Sinusoid<T> where T: Float + Copy { + pub fn period(&self) -> T { + self.frequency.recip() + } +} +impl<T> Sinusoid<T> where T: Float + Add<Output=T> + Mul<Output=T> + From<u8> + Trig + Copy + std::fmt::Display { + pub fn radial_frequency(&self) -> T { + (T::from(2))*T::PI()*self.frequency + } + pub fn sample(&self, t: T) -> T { + (self.radial_frequency()*t + self.phase).cos() * self.amplitude + } +} + +#[cfg(test)] +mod tests { + use super::*; + use std::f32; + + #[test] + fn period() { + let sinusoid = Sinusoid::new(1.0 as f32, 0.5, 0.0); + assert!((sinusoid.period()-2.0) < f32::EPSILON); + } + #[test] + fn radial_f() { + let sinusoid = Sinusoid::new(1.0 as f32, 1.0, 0.0); + assert!((sinusoid.radial_frequency()-2.0*f32::consts::PI) < f32::EPSILON); + } + + #[test] + fn sample() { + let sinusoid = Sinusoid::new(1.0 as f32, 1.0, -f32::consts::PI/2.0); //AKA sin + + assert!((sinusoid.sample(0.0)-0.0) < f32::EPSILON); + assert!((sinusoid.sample(0.25)-1.0) < f32::EPSILON); + assert!((sinusoid.sample(0.5)-0.0) < f32::EPSILON); + assert!((sinusoid.sample(0.75)+1.0) < f32::EPSILON); + assert!((sinusoid.sample(1.0)-0.0) < f32::EPSILON); + } +} |