# iq\_osc.rs – I/Q oscillator without trig function calls
[Documentation](https://docs.rs/iq_osc)
Given f(t) = cos(θ<sub>0</sub> + ωt) = cos Φ(t), an oscillator is defined here
to evaluate f(0), f(1), f(2), ... in sequence to generate a sinusoidal signal.
Further, a *quadrature* oscillator also evaluates g(t) = sin Φ(t) at each step
for the quadrature signal.
Computing these trig functions at each evaluation of f(t) and g(t) can be costly with
a high sample rate or within a tight loop. As an alternative, this crate implements a
quadrature oscillator that replaces the 2 trig function calls at each evaluation with
6 arithmetic operations (4 multiplies, 1 addition, and 1 subtraction.)
## Usage
This [crate](https://crates.io/crates/iq_osc) can be used through cargo by
adding it as a dependency in `Cargo.toml`:
```toml
[dependencies]
iq_osc = "3.0.0"
```
and importing it in the crate root:
```rust
extern crate iq_osc;
```