Merge pull request #321 from nyx-space/320-support-spk-type-3-chebyshev-position-and-velocity

Support SPK Type 3 chebyshev position and velocity

Author: ChristopherRabotin

.github/workflows/rust.yml

@@ -43,6 +43,7 @@ jobs:
           wget -O data/de430.bsp http://public-data.nyxspace.com/anise/de430.bsp
           wget -O data/de440s.bsp http://public-data.nyxspace.com/anise/de440s.bsp
           wget -O data/de440.bsp http://public-data.nyxspace.com/anise/de440.bsp
+          wget -O data/de440_type3.bsp http://public-data.nyxspace.com/anise/de440_type3.bsp
           wget -O data/pck08.pca http://public-data.nyxspace.com/anise/v0.4/pck08.pca
           wget -O data/pck11.pca http://public-data.nyxspace.com/anise/v0.4/pck11.pca
           wget -O data/moon_fk.epa http://public-data.nyxspace.com/anise/v0.4/moon_fk.epa
@@ -112,6 +113,7 @@ jobs:
           wget -O data/de430.bsp http://public-data.nyxspace.com/anise/de430.bsp
           wget -O data/de440s.bsp http://public-data.nyxspace.com/anise/de440s.bsp
           wget -O data/de440.bsp http://public-data.nyxspace.com/anise/de440.bsp
+          wget -O data/de440_type3.bsp http://public-data.nyxspace.com/anise/de440_type3.bsp
           wget -O data/pck08.pca http://public-data.nyxspace.com/anise/v0.4/pck08.pca
           wget -O data/pck11.pca http://public-data.nyxspace.com/anise/v0.4/pck11.pca
           wget -O data/gmat-hermite.bsp http://public-data.nyxspace.com/anise/ci/gmat-hermite.bsp
@@ -182,6 +184,7 @@ jobs:
           wget -O data/de430.bsp http://public-data.nyxspace.com/anise/de430.bsp
           wget -O data/de440s.bsp http://public-data.nyxspace.com/anise/de440s.bsp
           wget -O data/de440.bsp http://public-data.nyxspace.com/anise/de440.bsp
+          wget -O data/de440_type3.bsp http://public-data.nyxspace.com/anise/de440_type3.bsp
           wget -O data/pck08.pca http://public-data.nyxspace.com/anise/v0.4/pck08.pca
           wget -O data/pck11.pca http://public-data.nyxspace.com/anise/v0.4/pck11.pca
           wget -O data/gmat-hermite.bsp http://public-data.nyxspace.com/anise/ci/gmat-hermite.bsp
@@ -214,6 +217,7 @@ jobs:
           cargo llvm-cov test --no-report validate_bpc_to_iau_rotations -- --nocapture --ignored
           cargo llvm-cov test --no-report validate_jplde_de440s_no_aberration --features spkezr_validation -- --nocapture --ignored
           cargo llvm-cov test --no-report validate_jplde_de440s_aberration_lt --features spkezr_validation -- --nocapture --ignored
+          cargo llvm-cov test --no-report validate_jplde_de440_type3_no_aberration --features spkezr_validation -- --nocapture --ignored
           cargo llvm-cov test --no-report validate_hermite_type13_from_gmat --features spkezr_validation -- --nocapture --ignored
           cargo llvm-cov test --no-report validate_lagrange_type9_with_varying_segment_sizes --features spkezr_validation -- --nocapture --ignored
           cargo llvm-cov test --no-report ut_embed --features embed_ephem

anise/src/ephemerides/translate_to_parent.rs

@@ -17,7 +17,9 @@ use crate::ephemerides::EphemInterpolationSnafu;
 use crate::hifitime::Epoch;
 use crate::math::cartesian::CartesianState;
 use crate::math::Vector3;
-use crate::naif::daf::datatypes::{HermiteSetType13, LagrangeSetType9, Type2ChebyshevSet};
+use crate::naif::daf::datatypes::{
+    HermiteSetType13, LagrangeSetType9, Type2ChebyshevSet, Type3ChebyshevSet,
+};
 use crate::naif::daf::{DAFError, DafDataType, NAIFDataSet, NAIFSummaryRecord};
 use crate::prelude::Frame;
 
@@ -64,6 +66,16 @@ impl Almanac {
                 data.evaluate(epoch, summary)
                     .context(EphemInterpolationSnafu)?
             }
+            DafDataType::Type3ChebyshevSextuplet => {
+                let data =
+                    spk_data
+                        .nth_data::<Type3ChebyshevSet>(idx_in_spk)
+                        .context(SPKSnafu {
+                            action: "fetching data for interpolation",
+                        })?;
+                data.evaluate(epoch, summary)
+                    .context(EphemInterpolationSnafu)?
+            }
             DafDataType::Type9LagrangeUnequalStep => {
                 let data = spk_data
                     .nth_data::<LagrangeSetType9>(idx_in_spk)

anise/src/math/interpolation/chebyshev.rs

@@ -57,3 +57,33 @@ pub fn chebyshev_eval(
     let deriv = (w[0] + normalized_time * dw[0] - dw[1]) / spline_radius_s;
     Ok((val, deriv))
 }
+
+/// Attempts to evaluate a Chebyshev polynomial given the coefficients, returning only the value
+///
+/// # Notes
+/// 1. At this point, the splines are expected to be in Chebyshev format and no verification is done.
+pub fn chebyshev_eval_poly(
+    normalized_time: f64,
+    spline_coeffs: &[f64],
+    eval_epoch: Epoch,
+    degree: usize,
+) -> Result<f64, InterpolationError> {
+    // Workspace array
+    let mut w = [0.0_f64; 3];
+
+    for j in (2..=degree + 1).rev() {
+        w[2] = w[1];
+        w[1] = w[0];
+        w[0] = (spline_coeffs
+            .get(j - 1)
+            .ok_or(InterpolationError::MissingInterpolationData { epoch: eval_epoch })?)
+            + (2.0 * normalized_time * w[1] - w[2]);
+    }
+
+    let val = (spline_coeffs
+        .first()
+        .ok_or(InterpolationError::MissingInterpolationData { epoch: eval_epoch })?)
+        + (normalized_time * w[0]);
+
+    Ok(val)
+}

anise/src/math/interpolation/mod.rs

@@ -12,7 +12,7 @@ mod chebyshev;
 mod hermite;
 mod lagrange;
 
-pub use chebyshev::chebyshev_eval;
+pub use chebyshev::{chebyshev_eval, chebyshev_eval_poly};
 pub use hermite::hermite_eval;
 use hifitime::Epoch;
 pub use lagrange::lagrange_eval;

anise/src/naif/daf/datatypes/chebyshev.rs

@@ -271,51 +271,6 @@ impl<'a> NAIFDataRecord<'a> for Type2ChebyshevRecord<'a> {
     }
 }
 
-#[derive(PartialEq)]
-pub struct Type3ChebyshevRecord<'a> {
-    pub midpoint: Epoch,
-    pub radius: Duration,
-    pub x_coeffs: &'a [f64],
-    pub y_coeffs: &'a [f64],
-    pub z_coeffs: &'a [f64],
-    pub vx_coeffs: &'a [f64],
-    pub vy_coeffs: &'a [f64],
-    pub vz_coeffs: &'a [f64],
-}
-
-impl<'a> fmt::Display for Type3ChebyshevRecord<'a> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(
-            f,
-            "start: {}\tend: {}\nx:  {:?}\ny:  {:?}\nz:  {:?}\nvx: {:?}\nvy: {:?}\nvz: {:?}",
-            self.midpoint - self.radius,
-            self.midpoint + self.radius,
-            self.x_coeffs,
-            self.y_coeffs,
-            self.z_coeffs,
-            self.vx_coeffs,
-            self.vy_coeffs,
-            self.vz_coeffs
-        )
-    }
-}
-
-impl<'a> NAIFDataRecord<'a> for Type3ChebyshevRecord<'a> {
-    fn from_slice_f64(slice: &'a [f64]) -> Self {
-        let num_coeffs = (slice.len() - 2) / 6;
-        Self {
-            midpoint: Epoch::from_et_seconds(slice[0]),
-            radius: slice[1].seconds(),
-            x_coeffs: &slice[2..num_coeffs],
-            y_coeffs: &slice[2 + num_coeffs..num_coeffs * 2],
-            z_coeffs: &slice[2 + num_coeffs * 2..num_coeffs * 3],
-            vx_coeffs: &slice[2 + num_coeffs * 3..num_coeffs * 4],
-            vy_coeffs: &slice[2 + num_coeffs * 4..num_coeffs * 5],
-            vz_coeffs: &slice[2 + num_coeffs * 5..],
-        }
-    }
-}
-
 #[cfg(test)]
 mod chebyshev_ut {
     use crate::{