use dynamic height range for plotting example chart

examples/plot.rs

@@ -119,21 +119,6 @@ fn main() -> Result<(), Box<dyn Error>> {
 
     println!("Training complete, collecting data and building chart...");
 
-    let root = SVGBackend::new(OUTPUT_FILE_NAME, (640, 480)).into_drawing_area();
-    root.fill(&WHITE)?;
-
-    let mut chart = ChartBuilder::on(&root)
-        .caption(
-            "agent fitness values per generation",
-            ("sans-serif", 50).into_font(),
-        )
-        .margin(5)
-        .x_label_area_size(30)
-        .y_label_area_size(30)
-        .build_cartesian_2d(0usize..GENS, 0f32..1000.0)?;
-
-    chart.configure_mesh().draw()?;
-
     let data: Vec<_> = Arc::into_inner(performance_stats)
         .unwrap()
         .into_inner()
@@ -142,9 +127,16 @@ fn main() -> Result<(), Box<dyn Error>> {
         .enumerate()
         .collect();
 
-    let highs = data
+    let highs: Vec<_> = data
+        .iter()
+        .map(|(i, PerformanceStats { high, .. })| (*i, *high))
+        .collect();
+
+    let highest_overall = highs
         .iter()
-        .map(|(i, PerformanceStats { high, .. })| (*i, *high));
+        .map(|(_, h)| h)
+        .max_by(|&a, &b| a.partial_cmp(b).unwrap())
+        .unwrap();
 
     let medians = data
         .iter()
@@ -154,6 +146,21 @@ fn main() -> Result<(), Box<dyn Error>> {
         .iter()
         .map(|(i, PerformanceStats { low, .. })| (*i, *low));
 
+    let root = SVGBackend::new(OUTPUT_FILE_NAME, (640, 480)).into_drawing_area();
+    root.fill(&WHITE)?;
+
+    let mut chart = ChartBuilder::on(&root)
+        .caption(
+            "agent fitness values per generation",
+            ("sans-serif", 50).into_font(),
+        )
+        .margin(5)
+        .x_label_area_size(30)
+        .y_label_area_size(30)
+        .build_cartesian_2d(0usize..GENS, 0f32..*highest_overall)?;
+
+    chart.configure_mesh().draw()?;
+
     chart
         .draw_series(LineSeries::new(highs, &GREEN))?
         .label("high");