Src. Provide the lognormal distribution option

diff --git a/src/main.rs b/src/main.rs
index 5a9531bbc0a1a4ab507689a780c0baf09b1604eb..a802abea854070009ec345efea19dea819e67e2b 100644 (file)
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,8 +4,9 @@
 
 use std::io; // bring flush() into scope with `use std::io::Write`
 use std::io::prelude::*; // Bring `std::io::BufRead` in scope
-use statrs::distribution::{Exp, ContinuousCDF}; // Continuous needed for pdf
+use statrs::distribution::{Exp, LogNormal, ContinuousCDF}; // Continuous needed for pdf
 // use statrs::statistics::Distribution;
+// use statrs::prec;
 
 const DEBUG: bool = false;
 
@@ -70,12 +71,34 @@ fn exp(n: i32) -> Vec<f64> {
 }
 
 
+fn lognormal(n: i32) -> Vec<f64> {
+    const NAME: &str = "Lognormal"; // mean of normal distribution (N)
+    const MEAN: f64 = 0.0;        // is unessential thanks to
+    const STD: f64 = 1.0;         // normalization, and std of N
+    let dist = LogNormal::new(MEAN, STD).unwrap();
+    let mut prio: Vec<f64> = Vec::new();
+    if DEBUG { eprint!("{}: ", NAME) }
+    for i in 1..n + 1 {
+        let f = i as f64 / (n as f64 + 1.0);
+        let x = dist.inverse_cdf(f);
+        if DEBUG {
+            eprint!("i = {}, f = {:.2}, x = {:.2}; ", i, f, x);
+        }
+        prio.push(x);
+    }
+    if DEBUG { eprintln!("\x08\x08."); }
+    prio.reverse();
+    normalize(prio)
+}
+
+
 fn main() {
 
     let ranked: Vec<String> = input();
     let num = ranked.len() as i32;
     let _prio1 = delta(num);
-    let prio2 = exp(num);
+    let _prio2 = exp(num);
+    let prio3 = lognormal(num);
 
     if DEBUG {
         for l in ranked.iter() {
@@ -84,6 +107,6 @@ fn main() {
         eprintln!("\x08\x08.");
     }
 
-    output(&prio2, &ranked);
+    output(&prio3, &ranked);
 
 }