Data commit

Task/Cumulative-standard-deviation/Rust/cumulative-standard-deviation-1.rust

@@ -0,0 +1,32 @@
+pub struct CumulativeStandardDeviation {
+    n: f64,
+    sum: f64,
+    sum_sq: f64
+}
+
+impl CumulativeStandardDeviation {
+    pub fn new() -> Self {
+        CumulativeStandardDeviation {
+            n: 0.,
+            sum: 0.,
+            sum_sq: 0.
+        }
+    }
+
+    fn push(&mut self, x: f64) -> f64 {
+        self.n += 1.;
+        self.sum += x;
+        self.sum_sq += x * x;
+
+        (self.sum_sq / self.n - self.sum * self.sum / self.n / self.n).sqrt()
+    }
+}
+
+fn main() {
+    let nums = [2, 4, 4, 4, 5, 5, 7, 9];
+
+    let mut cum_stdev = CumulativeStandardDeviation::new();
+    for num in nums.iter() {
+        println!("{}", cum_stdev.push(*num as f64));
+    }
+}

Task/Cumulative-standard-deviation/Rust/cumulative-standard-deviation-2.rust

@@ -0,0 +1,20 @@
+fn sd_creator() -> impl FnMut(f64) -> f64 {
+    let mut n = 0.0;
+    let mut sum = 0.0;
+    let mut sum_sq = 0.0;
+    move |x| {
+        sum += x;
+        sum_sq += x*x;
+        n += 1.0;
+        (sum_sq / n - sum * sum / n / n).sqrt()
+    }
+}
+
+fn main() {
+    let nums = [2, 4, 4, 4, 5, 5, 7, 9];
+
+    let mut sd_acc = sd_creator();
+    for num in nums.iter() {
+        println!("{}", sd_acc(*num as f64));
+    }
+}