dsp 0.11.0

Digital Signal Processing
Documentation 
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#[macro_use]
extern crate clap;

use gnuplot::{Figure, Color, AxesCommon};
use clap::{Arg, App};
use dsp::runtime::node::SourceNode;
use dsp::node::generator::*;


const SIGNAL_LENGTH: usize = 512;


// Application params
struct Params {
    gen_name: String,
    sample_rate: usize,
    freq: f32
}

/// Parse command line arguments
fn parse_params() -> Params {
    let args = App::new("Plot signal")
                .arg(Arg::with_name("gen")
                    .short("g")
                    .long("generator-name")
                    .help("Select generator type")
                    .takes_value(true))
                .arg(Arg::with_name("freq")
                    .short("f")
                    .long("frequency")
                    .help("Frequency in Hz")
                    .takes_value(true))
                .arg(Arg::with_name("sample-rate")
                    .short("s")
                    .long("sample-rate")
                    .help("Number of samples per period")
                    .takes_value(true))
                .get_matches();
    let gen_name = args.value_of("gen").unwrap_or("sine"); 
    let sample_rate = value_t!(args, "sample-rate", usize).unwrap_or(512);
    let freq = value_t!(args, "freq", f32).unwrap_or(4.0);
    Params { gen_name: gen_name.to_string(),
             sample_rate: sample_rate,
             freq: freq }
}

/// Create signal
fn create_generator(params: &Params) -> Box<dyn SourceNode<f32>> {
    match params.gen_name.as_ref() {
        "sawtooth"  => Box::new(Sawtooth::new(params.freq, params.sample_rate)),
        "square"    => Box::new(Square::new(params.freq, params.sample_rate)),
        "noise"     => Box::new(Noise::new(0.1)),
        "chirp"     => Box::new(Chirp::new(4.0, 1.0, 10.0, params.sample_rate)),
        _           => Box::new(Sine::new(params.freq, params.sample_rate)),
    }
}

fn main() {
    let params = parse_params();
    let mut generator = create_generator(&params);
    let mut buffer = vec![0.0; SIGNAL_LENGTH];
    let _ = generator.write_buffer(&mut buffer);

    // Plot signal with ms as units
    let idx: Vec<usize> = (0..buffer.len()).map(|i| i * 1000 / params.sample_rate).collect();
    let mut fg = Figure::new();
    fg.set_title("Scope plot");
    let axes = fg.axes2d();
    axes.lines(&idx, buffer, &[Color("red")]);
    axes.set_x_label("Time in ms", &[]);
    fg.show().unwrap();
}