Change time to use i64 instead of u64

examples/atp.rs

@@ -1,3 +1,4 @@
+use plotters::prelude::*;
 use time::Date;
 use trueskill_tt::{History, IndexMap};
 
@@ -37,13 +38,104 @@ fn main() {
             .assume_utc()
             .unix_timestamp();
 
-        times.push(time as u64 / (60 * 60 * 24));
+        times.push(time / (60 * 60 * 24));
     }
 
     let mut hist = History::builder().sigma(1.6).gamma(0.036).build();
 
     hist.add_events(composition, results, times, vec![]);
     hist.convergence(10, 0.01, true);
+
+    let players = [
+        ("djokovic", "d643"),
+        ("federer", "f324"),
+        ("sampras", "s402"),
+        ("lendl", "l018"),
+        ("connors", "c044"),
+        ("nadal", "n409"),
+        ("john_mcenroe", "m047"),
+        ("bjorn_borg", "b058"),
+        ("aggasi", "a092"),
+        ("hewitt", "h432"),
+        ("edberg", "e004"),
+        ("vilas", "v028"),
+        ("nastase", "n008"),
+        ("courier", "c243"),
+        ("kuerten", "k293"),
+        ("murray", "mc10"),
+        ("wilander", "w023"),
+        ("roddick", "r485"),
+    ];
+
+    let curves = hist.learning_curves();
+
+    let mut x_spec = (f64::MAX, f64::MIN);
+    let mut y_spec = (f64::MAX, f64::MIN);
+
+    for id in players.iter().map(|&(_, id)| index_map.get_or_create(id)) {
+        for (ts, gs) in &curves[&id] {
+            let ts = *ts as f64;
+
+            if ts < x_spec.0 {
+                x_spec.0 = ts;
+            }
+
+            if ts > x_spec.1 {
+                x_spec.1 = ts;
+            }
+
+            let mu = gs.mu as f64;
+
+            if mu < y_spec.0 {
+                y_spec.0 = mu;
+            }
+
+            if mu > y_spec.1 {
+                y_spec.1 = mu;
+            }
+        }
+    }
+
+    let root = SVGBackend::new("plot.svg", (1024, 1024)).into_drawing_area();
+
+    root.fill(&WHITE).unwrap();
+
+    let mut chart = ChartBuilder::on(&root)
+        .caption("Hello world", ("sans-serif", 50).into_font())
+        .margin(5)
+        .x_label_area_size(30)
+        .y_label_area_size(30)
+        .build_cartesian_2d(x_spec.0..x_spec.1, y_spec.0..y_spec.1)
+        .unwrap();
+
+    chart.configure_mesh().draw().unwrap();
+
+    for (idx, (player, id)) in players
+        .iter()
+        .map(|&(player, id)| (player, index_map.get_or_create(id)))
+        .enumerate()
+    {
+        let mut data = Vec::new();
+
+        for (ts, gs) in &curves[&id] {
+            data.push((*ts as f64, gs.mu));
+        }
+
+        let color = Palette99::pick(idx);
+
+        chart
+            .draw_series(LineSeries::new(data, &color))
+            .unwrap()
+            .label(format!("{}", player))
+            .legend(move |(x, y)| PathElement::new(vec![(x, y), (x + 20, y)], &color));
+    }
+
+    chart
+        .configure_series_labels()
+        .background_style(&WHITE.mix(0.8))
+        .border_style(&BLACK)
+        .draw()
+        .unwrap();
 }
 
 mod csv {