basic_usage/
basic_usage.rs

1//! Basic usage example for rust-jpl
2//!
3//! This example demonstrates how to:
4//! - Initialize an ephemeris
5//! - Convert between calendar dates and Julian dates
6//! - Get planetary positions
7//! - Access ephemeris metadata
8
9use rust_jpl::Ephemeris;
10
11fn main() -> Result<(), Box<dyn std::error::Error>> {
12    println!("=== Rust JPL Ephemeris Reader - Basic Usage Example ===\n");
13
14    // Initialize the ephemeris from config.toml
15    println!("1. Initializing Ephemeris...");
16    let eph = Ephemeris::new("config.toml")?;
17    println!("   ✓ Ephemeris loaded successfully\n");
18
19    // Display metadata
20    println!("2. Ephemeris Metadata:");
21    let metadata = eph.get_metadata();
22    println!(
23        "   - Date Range: {} - {}",
24        metadata.start_year, metadata.end_year
25    );
26    println!(
27        "   - Julian Date Range: {:.2} - {:.2}",
28        metadata.julian_start, metadata.julian_end
29    );
30    println!("   - Interval: {} days", metadata.interval_days);
31    println!(
32        "   - Earth-Moon Mass Ratio: {:.6}",
33        metadata.earth_moon_ratio
34    );
35    println!(
36        "   - Number of Coefficients: {}\n",
37        metadata.number_of_coefficients
38    );
39
40    // List available bodies
41    println!("3. Available Celestial Bodies:");
42    for body in eph.get_bodies() {
43        let status = if body.active { "✓" } else { "✗" };
44        println!(
45            "   {} {} ({})",
46            status,
47            body.name,
48            if body.active { "active" } else { "inactive" }
49        );
50    }
51    println!();
52
53    // Time conversion example
54    println!("4. Time Conversion Example:");
55    let calendar_date = rust_jpl::CalendarDate::new(2024, 1, 15, 12, 0, 0.0);
56    println!(
57        "   Calendar Date: {}-{:02}-{:02} {:02}:{:02}:{:02}",
58        calendar_date.year,
59        calendar_date.month,
60        calendar_date.day,
61        calendar_date.hour,
62        calendar_date.minute,
63        calendar_date.second as i32
64    );
65
66    let jd = calendar_date.to_julian()?;
67    println!("   Julian Date: {:.6}", jd.as_f64());
68
69    let converted_back = jd.to_calendar();
70    println!(
71        "   Converted back: {}-{:02}-{:02} {:02}:{:02}:{:02}\n",
72        converted_back.year,
73        converted_back.month,
74        converted_back.day,
75        converted_back.hour,
76        converted_back.minute,
77        converted_back.second as i32
78    );
79
80    // Get planetary positions
81    println!(
82        "5. Planetary Positions (at Julian Date {:.6}):",
83        jd.as_f64()
84    );
85    let bodies = [
86        "Sun", "Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn",
87    ];
88
89    for body_name in &bodies {
90        match eph.get_position(body_name, jd) {
91            Ok(pos) => {
92                println!(
93                    "   {}: ({:12.6}, {:12.6}, {:12.6}) AU, Distance: {:.6} AU",
94                    body_name,
95                    pos.x,
96                    pos.y,
97                    pos.z,
98                    pos.distance()
99                );
100            }
101            Err(e) => {
102                println!("   {}: Error - {}", body_name, e);
103            }
104        }
105    }
106
107    println!("\n=== Example Complete ===");
108    Ok(())
109}
basic_usage/basic_usage.rs

basic_usage/
basic_usage.rs
