Add serialization methods for NavigationResult

Fixes #52

Author: jbrodovsky

core/src/earth.rs

@@ -353,6 +353,21 @@ pub fn gravitation(latitude: &f64, longitude: &f64, altitude: &f64) -> Vector3<f
     gravity + rot * omega_ie * omega_ie * ecef_vec
 }
 /// Calculate local gravity anomaly from IMU accelerometer measurements
+/// 
+/// This function calculates the local gravity anomaly by comparing the observed gravity from the
+/// IMU accelerometer measurements (eg: $\sqrt(a_x^2 + a_y^2 + a_z^2)$) with the normal gravity 
+/// at the given latitude and altitude via the Somigliana method. Additionally, this function 
+/// compensates for the motion of the platform (if any) using the Eötvös correction.
+/// 
+/// # Parameters
+/// - `latitude` - The WGS84 latitude in degrees
+/// - `altitude` - The WGS84 altitude in meters
+/// - `north_velocity` - The northward velocity component in m/s
+/// - `east_velocity` - The eastward velocity component in m/s
+/// - `gravity_observed` - The observed gravity from the IMU accelerometer measurements in m/s^2
+/// 
+/// # Returns
+/// The local gravity anomaly in m/s^2, which is the difference between the observed gravity and the normal gravity at the given latitude and altitude, adjusted for the Eötvös correction.
 pub fn gravity_anomaly(
     latitude: &f64,
     altitude: &f64,

core/src/main.rs

@@ -23,27 +23,14 @@ struct Args {
     #[clap(long, value_parser)]
     gps_interval: Option<usize>,
 }
-
-fn write_results_to_csv(
-    // TODO: make this public and move to sim.rs
-    results: &[NavigationResult],
-    output: &PathBuf,
-) -> Result<(), Box<dyn Error>> {
-    let mut wtr = WriterBuilder::new().from_path(output)?;
-    for result in results {
-        wtr.serialize(result)?;
-    }
-    wtr.flush()?;
-    Ok(())
-}
 fn main() -> Result<(), Box<dyn Error>> {
     let args = Args::parse();
-    // Read the input CSV file
-    let mut rdr = ReaderBuilder::new().from_path(&args.input)?;
     // Validate the mode
     if args.mode != "open-loop" && args.mode != "closed-loop" {
         return Err("Invalid mode specified. Use 'open-loop' or 'closed-loop'.".into());
     }
+    // Read the input CSV file
+    let mut rdr = ReaderBuilder::new().from_path(&args.input)?;
     let records: Vec<TestDataRecord> = rdr.deserialize().collect::<Result<_, _>>()?;
     println!(
         "Read {} records from {}",
@@ -58,13 +45,15 @@ fn main() -> Result<(), Box<dyn Error>> {
         );
 
         results = closed_loop(&records, args.gps_interval);
-        match write_results_to_csv(&results, &args.output) {
+        //match write_results_to_csv(&results, &args.output) {
+        match NavigationResult::to_csv(&results, &args.output) {
             Ok(_) => println!("Results written to {}", args.output.display()),
             Err(e) => eprintln!("Error writing results: {}", e),
         };
     } else if args.mode == "open-loop" {
         results = dead_reckoning(&records);
-        match write_results_to_csv(&results, &args.output) {
+        // match write_results_to_csv(&results, &args.output) {
+        match NavigationResult::to_csv(&results, &args.output) {
             Ok(_) => println!("Results written to {}", args.output.display()),
             Err(e) => eprintln!("Error writing results: {}", e),
         };

core/src/sim.rs

@@ -754,6 +754,7 @@ impl
         }
     }
 }
+
 /// Run dead reckoning or "open-loop" simulation using test data.
 ///
 /// This function processes a sequence of sensor records through a StrapdownState, using