Averages/Mean time of day: Difference between revisions

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        end if
 End Function</lang>
+=={{header|Rust}}==
+<lang rust>
+use std::f64::consts::PI;
+#[derive(Debug, PartialEq, Eq)]
+struct Time {
+    h: u8,
+    m: u8,
+    s: u8,
+}
+impl Time {
+    /// Create a Time from equivalent radian measure
+    fn from_radians(mut rads: f64) -> Time {
+        rads %= 2.0 * PI;
+        if rads < 0.0 {
+            rads += 2.0 * PI
+        }
+        Time {
+            h: (rads * 12.0 / PI) as u8,
+            m: ((rads * 720.0 / PI) % 60.0) as u8,
+            s: ((rads * 43200.0 / PI) % 60.0).round() as u8,
+        }
+    }
+    /// Create a Time from H/M/S
+    fn from_parts(h: u8, m: u8, s: u8) -> Result<Time, ()> {
+        if h > 23 || m > 59 || s > 59 {
+            return Err(());
+        }
+        Ok(Time { h, m, s })
+    }
+    /// Return time as measure in radians
+    fn as_radians(&self) -> f64 {
+        ((self.h as f64 / 12.0) + (self.m as f64 / 720.0) + (self.s as f64 / 43200.0)) * PI
+    }
+}
+/// Compute the mean time from a slice of times
+fn mean_time(times: &[Time]) -> Time {
+    // compute sum of sines and cosines
+    let (ss, sc) = times
+        .iter()
+        .map(Time::as_radians)
+        .map(|a| (a.sin(), a.cos()))
+        .fold((0.0, 0.0), |(ss, sc), (s, c)| (ss + s, sc + c));
+    // scaling does not matter for atan2, meaning we do not have to divide sums by len
+    Time::from_radians(ss.atan2(sc))
+}
+fn main() {
+    let times = [
+        Time::from_parts(23, 00, 17).unwrap(),
+        Time::from_parts(23, 40, 20).unwrap(),
+        Time::from_parts(00, 12, 45).unwrap(),
+        Time::from_parts(00, 17, 19).unwrap(),
+    ];
+    let mean = mean_time(&times);
+    println!("{:02}:{:02}:{:02}", mean.h, mean.m, mean.s);
+}
+</lang>
+{{out}}
+<pre>
+:47:43
+</pre>
 =={{header|Scala}}==