Move a few modules to util

src/util/min_max.rs

@@ -0,0 +1,30 @@
+use std::iter::Iterator;
+
+/// A max function for f64's without NaNs
+pub fn max(vals: &[f64]) -> f64 {
+    *vals
+        .iter()
+        .max_by(|a, b| a.partial_cmp(b).unwrap())
+        .unwrap()
+}
+
+/// A min function for f64's without NaNs
+pub fn min(vals: &[f64]) -> f64 {
+    *vals
+        .iter()
+        .min_by(|a, b| a.partial_cmp(b).unwrap())
+        .unwrap()
+}
+
+#[test]
+fn test_max() {
+    let assert_float_eq = |a: f64, b: f64| {
+        assert!((a - b).abs() < f64::EPSILON);
+    };
+
+    assert_float_eq(1.0, max(&[1.0]));
+    assert_float_eq(-1.0, max(&[-1.0]));
+    assert_float_eq(-1.0, max(&[-2.0, -1.0]));
+    assert_float_eq(1.0, max(&[-1.0, 1.0]));
+    assert_float_eq(1.0, max(&[-1.0, 1.0, 0.0]));
+}