yagi 0.1.3

Batteries-included DSP library
Documentation 
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use crate::error::{Error, Result};
use crate::filter::iir::iirfilt::IirFilter;
use crate::filter::iir::design::{IirFilterShape, IirBandType, IirFormat};

use num_complex::Complex32;

#[derive(Clone, Debug)]
pub struct IirHilbertFilter {
    filt_0: IirFilter<f32, f32>,
    filt_1: IirFilter<f32, f32>,
    state: u8,
}

impl IirHilbertFilter {
    pub fn new(ftype: IirFilterShape, n: usize, ap: f32, as_: f32) -> Result<Self> {
        if n == 0 {
            return Err(Error::Config("filter order must be greater than zero".into()));
        }

        let btype = IirBandType::Lowpass;
        let format = IirFormat::SecondOrderSections;
        let fc = 0.25;
        let f0 = 0.0;

        let filt_0 = IirFilter::new_prototype(ftype, btype, format, n, fc, f0, ap, as_)?;
        let filt_1 = IirFilter::new_prototype(ftype, btype, format, n, fc, f0, ap, as_)?;

        let mut q = Self {
            filt_0,
            filt_1,
            state: 0,
        };

        q.reset();
        Ok(q)
    }

    pub fn new_default(n: usize) -> Result<Self> {
        if n == 0 {
            return Err(Error::Config("filter order must be greater than zero".into()));
        }

        let ftype = IirFilterShape::Butter;
        let ap = 0.1;
        let as_ = 60.0;
        Self::new(ftype, n, ap, as_)
    }

    pub fn reset(&mut self) {
        self.filt_0.reset();
        self.filt_1.reset();
        self.state = 0;
    }

    pub fn r2c_execute(&mut self, x: f32) -> Complex32 {
        let y = match self.state {
            0 => {
                let yi = self.filt_0.execute(x);
                let yq = self.filt_1.execute(0.0);
                2.0 * Complex32::new(yi, yq)
            },
            1 => {
                let yi = self.filt_0.execute(0.0);
                let yq = self.filt_1.execute(-x);
                2.0 * Complex32::new(-yq, yi)
            },
            2 => {
                let yi = self.filt_0.execute(-x);
                let yq = self.filt_1.execute(0.0);
                2.0 * Complex32::new(-yi, -yq)
            },
            3 => {
                let yi = self.filt_0.execute(0.0);
                let yq = self.filt_1.execute(x);
                2.0 * Complex32::new(yq, -yi)
            },
            _ => unreachable!(),
        };

        self.state = (self.state + 1) & 0x3;
        y
    }

    pub fn r2c_execute_block(&mut self, x: &[f32], y: &mut [Complex32]) {
        for (&xi, yi) in x.iter().zip(y.iter_mut()) {
            *yi = self.r2c_execute(xi);
        }
    }

    pub fn c2r_execute(&mut self, x: Complex32) -> f32 {
        let y = match self.state {
            0 => {
                let yi = self.filt_0.execute(x.re);
                let _yq = self.filt_1.execute(x.im);
                yi
            },
            1 => {
                let _yi = self.filt_0.execute(x.im);
                let yq = self.filt_1.execute(-x.re);
                -yq
            },
            2 => {
                let yi = self.filt_0.execute(-x.re);
                let _yq = self.filt_1.execute(-x.im);
                -yi
            },
            3 => {
                let _yi = self.filt_0.execute(-x.im);
                let yq = self.filt_1.execute(x.re);
                yq
            },
            _ => unreachable!(),
        };

        self.state = (self.state + 1) & 0x3;
        y
    }

    pub fn c2r_execute_block(&mut self, x: &[Complex32], y: &mut [f32]) {
        for (&xi, yi) in x.iter().zip(y.iter_mut()) {
            *yi = self.c2r_execute(xi);
        }
    }

    pub fn decim_execute(&mut self, x: &[f32]) -> Complex32 {
        let xi = if self.state != 0 { -x[0] } else { x[0] };
        let xq = if self.state != 0 { x[1] } else { -x[1] };

        let yi0 = self.filt_0.execute(xi);
        let _yi1 = self.filt_0.execute(0.0);

        let yq0 = self.filt_1.execute(0.0);
        let _yq1 = self.filt_1.execute(xq);

        let y = 2.0 * Complex32::new(yi0, yq0);

        self.state = 1 - self.state;
        y
    }

    pub fn decim_execute_block(&mut self, x: &[f32], y: &mut [Complex32]) {
        for (x_chunk, yi) in x.chunks_exact(2).zip(y.iter_mut()) {
            *yi = self.decim_execute(x_chunk);
        }
    }

    pub fn interp_execute(&mut self, x: Complex32, y: &mut [f32]) {
        let yi0 = self.filt_0.execute(x.re);
        let _yi1 = self.filt_0.execute(0.0);

        let _yq0 = self.filt_1.execute(x.im);
        let yq1 = self.filt_1.execute(0.0);

        y[0] = if self.state != 0 { -2.0 * yi0 } else { 2.0 * yi0 };
        y[1] = if self.state != 0 { 2.0 * yq1 } else { -2.0 * yq1 };

        self.state = 1 - self.state;
    }

    pub fn interp_execute_block(&mut self, x: &[Complex32], y: &mut [f32]) {
        for (&xi, yi) in x.iter().zip(y.chunks_exact_mut(2)) {
            self.interp_execute(xi, yi);
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use test_macro::autotest_annotate;
    use crate::filter;
    use crate::math::kaiser;
    use crate::utility::test_helpers::{PsdRegion, validate_psd_signal, validate_psd_signalf};

    #[test]
    #[autotest_annotate(autotest_iirhilbf_interp_decim)]
    fn test_iirhilbf_interp_decim() {
        let tol = 1.0;  // error tolerance [dB]
        let bw = 0.4;   // pulse bandwidth
        let as_ = 60.0; // transform stop-band suppression
        let p = 40;     // pulse semi-length
        let m = 5;      // Transform order

        // create transform
        let mut q = IirHilbertFilter::new_default(m).unwrap();
        // q.print();

        let h_len = 2 * p + 1;  // pulse length
        let num_samples = h_len + 2 * m + 8;

        let mut buf_0 = vec![Complex32::new(0.0, 0.0); num_samples];
        let mut buf_1 = vec![0.0; num_samples * 2];
        let mut buf_2 = vec![Complex32::new(0.0, 0.0); num_samples];

        // generate the baseband signal (filter pulse)
        let w = 0.36 * bw; // pulse bandwidth
        let h = filter::fir_design_kaiser(h_len, w, 80.0, 0.0).unwrap();
        for i in 0..num_samples {
            buf_0[i] = Complex32::new(if i < h_len { 2.0 * w * h[i] } else { 0.0 }, 0.0);
        }

        // run interpolation
        q.interp_execute_block(&buf_0, &mut buf_1);

        // clear object
        q.reset();

        // run decimation
        q.decim_execute_block(&buf_1, &mut buf_2);

        // verify input spectrum
        let regions_orig = vec![
            PsdRegion { fmin: -0.5,    fmax: -0.5*bw, pmin: 0.0, pmax: -as_+tol, test_lo: false, test_hi: true },
            PsdRegion { fmin: -0.3*bw, fmax: 0.3*bw,  pmin: -1.0, pmax: 1.0,     test_lo: true,  test_hi: true },
            PsdRegion { fmin: 0.5*bw,  fmax: 0.5,     pmin: 0.0, pmax: -as_+tol, test_lo: false, test_hi: true },
        ];
        assert!(validate_psd_signal(&buf_0, &regions_orig).unwrap());

        // verify interpolated spectrum
        let regions_interp = vec![
            PsdRegion { fmin: -0.5,           fmax: -0.25-0.25*bw, pmin: 0.0, pmax: -as_+tol, test_lo: false, test_hi: true },
            PsdRegion { fmin: -0.25-0.15*bw,  fmax: -0.25+0.15*bw, pmin: -1.0, pmax: 1.0,     test_lo: true,  test_hi: true },
            PsdRegion { fmin: -0.25+0.25*bw,  fmax: 0.25-0.25*bw,  pmin: 0.0, pmax: -as_+tol, test_lo: false, test_hi: true },
            PsdRegion { fmin: 0.25-0.15*bw,   fmax: 0.25+0.15*bw,  pmin: -1.0, pmax: 1.0,     test_lo: true,  test_hi: true },
            PsdRegion { fmin: 0.25+0.25*bw,   fmax: 0.5,           pmin: 0.0, pmax: -as_+tol, test_lo: false, test_hi: true },
        ];
        assert!(validate_psd_signalf(&buf_1, &regions_interp).unwrap());

        // verify decimated spectrum (using same regions as original)
        assert!(validate_psd_signal(&buf_2, &regions_orig).unwrap());
    }

    #[test]
    #[autotest_annotate(autotest_iirhilbf_filter)]
    fn test_iirhilbf_filter() {
        let tol: f32 = 1.0;  // error tolerance [dB]
        let bw: f32 = 0.2;   // pulse bandwidth
        let f0: f32 = 0.3;   // pulse center frequency
        let ft: f32 = -0.3;  // frequency of tone in lower half of band
        let as_: f32 = 60.0; // transform stop-band suppression
        let p: usize = 50;   // pulse semi-length
        let m: usize = 7;    // Transform order

        // create transform
        let mut q = IirHilbertFilter::new_default(m).unwrap();
        // q.print();

        let h_len: usize = 2 * p + 1; // pulse length
        let num_samples: usize = h_len + 2 * m + 8;

        let mut buf_0 = vec![Complex32::new(0.0, 0.0); num_samples];
        let mut buf_1 = vec![0.0; num_samples];
        let mut buf_2 = vec![Complex32::new(0.0, 0.0); num_samples];

        // generate the baseband signal (filter pulse)
        let w = 0.36 * bw;
        let h = filter::fir_design_kaiser(h_len, w, 80.0, 0.0).unwrap();
        for i in 0..num_samples {
            buf_0[i] = if i < h_len {
                2.0 * w * h[i] * Complex32::from_polar(1.0, 2.0 * std::f32::consts::PI * f0 * i as f32)
            } else {
                Complex32::new(0.0, 0.0)
            };
        }
        for i in 0..num_samples {
            buf_0[i] += if i < h_len {
                1e-3 * kaiser(i, num_samples, 10.0).unwrap() * Complex32::from_polar(1.0, 2.0 * std::f32::consts::PI * ft * i as f32)
            } else {
                Complex32::new(0.0, 0.0)
            };
        }

        // run interpolation
        q.c2r_execute_block(&buf_0, &mut buf_1);
        // scale output
        for i in 0..num_samples {
            buf_1[i] *= 2.0;
        }

        // clear object
        q.reset();

        // run decimation
        q.r2c_execute_block(&buf_1, &mut buf_2);
        // scale output
        for i in 0..num_samples {
            buf_2[i] *= 0.5;
        }

        // verify input spectrum
        let regions_orig = vec![
            PsdRegion { fmin: -0.5,       fmax: ft-0.03,   pmin: 0.0,  pmax: -as_+tol, test_lo: false, test_hi: true },
            PsdRegion { fmin: ft-0.01,    fmax: ft+0.01,   pmin: -40.0,pmax: 0.0,      test_lo: true,  test_hi: false },
            PsdRegion { fmin: ft+0.03,    fmax: f0-0.5*bw, pmin: 0.0,  pmax: -as_+tol, test_lo: false, test_hi: true },
            PsdRegion { fmin: f0-0.3*bw,  fmax: f0+0.3*bw, pmin: -1.0, pmax: 1.0,      test_lo: true,  test_hi: true },
            PsdRegion { fmin: f0+0.5*bw,  fmax: 0.5,       pmin: 0.0,  pmax: -as_+tol, test_lo: false, test_hi: true },
        ];
        assert!(validate_psd_signal(&buf_0, &regions_orig).unwrap());

        // verify interpolated spectrum
        let regions_c2r = vec![
            PsdRegion { fmin: -0.5,       fmax: -f0-0.5*bw, pmin: 0.0,  pmax: -as_+tol, test_lo: false, test_hi: true },
            PsdRegion { fmin: -f0-0.3*bw, fmax: -f0+0.3*bw, pmin: -1.0, pmax: 1.0,      test_lo: true,  test_hi: true },
            PsdRegion { fmin: -f0+0.5*bw, fmax: f0-0.5*bw,  pmin: 0.0,  pmax: -as_+tol, test_lo: false, test_hi: true },
            PsdRegion { fmin: f0-0.3*bw,  fmax: f0+0.3*bw,  pmin: -1.0, pmax: 1.0,      test_lo: true,  test_hi: true },
            PsdRegion { fmin: f0+0.5*bw,  fmax: 0.5,        pmin: 0.0,  pmax: -as_+tol, test_lo: false, test_hi: true },
        ];
        assert!(validate_psd_signalf(&buf_1, &regions_c2r).unwrap());

        // verify decimated spectrum (using same regions as original)
        let regions_r2c = vec![
            PsdRegion { fmin: -0.5,       fmax: f0-0.5*bw, pmin: 0.0,  pmax: -as_+tol, test_lo: false, test_hi: true },
            PsdRegion { fmin: f0-0.3*bw,  fmax: f0+0.3*bw, pmin: -1.0, pmax: 1.0,      test_lo: true,  test_hi: true },
            PsdRegion { fmin: f0+0.5*bw,  fmax: 0.5,       pmin: 0.0,  pmax: -as_+tol, test_lo: false, test_hi: true },
        ];
        assert!(validate_psd_signal(&buf_2, &regions_r2c).unwrap());
    }

    #[test]
    #[autotest_annotate(autotest_iirhilbf_invalid_config)]
    fn test_iirhilbf_invalid_config() {
        // check that object returns None for invalid configurations
        assert!(IirHilbertFilter::new(IirFilterShape::Butter, 0, 0.1, 60.0).is_err()); // order out of range
        assert!(IirHilbertFilter::new_default(0).is_err()); // order out of range

        // create proper object and test configuration methods
        // let q = IirHilb::new(IirdesFilterType::Butter, 5, 0.1, 60.0).unwrap();
        // q.print();
    }

    #[test]
    #[autotest_annotate(autotest_iirhilbf_copy_interp)]
    fn test_iirhilbf_copy_interp() {
        // create base object
        let mut q0 = IirHilbertFilter::new(IirFilterShape::Ellip, 7, 0.1, 80.0).unwrap();

        // run interpolator on random data
        let mut y0 = [0.0; 2];
        let mut y1 = [0.0; 2];
        for _ in 0..80 {
            let x = Complex32::new(crate::random::randnf(), crate::random::randnf());
            q0.interp_execute(x, &mut y0);
        }

        // copy object
        let mut q1 = q0.clone();

        for _ in 0..80 {
            let x = Complex32::new(crate::random::randnf(), crate::random::randnf());
            q0.interp_execute(x, &mut y0);
            q1.interp_execute(x, &mut y1);
            assert_eq!(y0[0], y1[0]);
            assert_eq!(y0[1], y1[1]);
        }
    }

    #[test]
    #[autotest_annotate(autotest_iirhilbf_copy_decim)]
    fn test_iirhilbf_copy_decim() {
        // create base object
        let mut q0 = IirHilbertFilter::new(IirFilterShape::Ellip, 7, 0.1, 80.0).unwrap();

        // run decimator on random data
        let mut x = [0.0; 2];
        for _ in 0..80 {
            x[0] = crate::random::randnf();
            x[1] = crate::random::randnf();
            let _y0 = q0.decim_execute(&x);
        }

        // copy object and run samples through each in parallel
        let mut q1 = q0.clone();
        for _ in 0..80 {
            x[0] = crate::random::randnf();
            x[1] = crate::random::randnf();
            let y0 = q0.decim_execute(&x);
            let y1 = q1.decim_execute(&x);
            assert_eq!(y0, y1);
        }
    }
}