Add barplot axis labels and increas plot width to 80 characters (#128)

* add barplot axis labels

* cargo fmt

src/boxplot.rs

@@ -1,8 +1,23 @@
 use log;
-const PLOT_WIDTH: usize = 40;
+use std::fmt::Write;
+
+const PLOT_WIDTH: usize = 80;
+
+fn generate_axis_labels(minima: f64, maxima: f64) -> String {
+    let mut labels = String::new();
+    write!(labels, "{:<10.2}", minima).unwrap();
+    write!(
+        labels,
+        "{:^width$.2}",
+        (minima + maxima) / 2.0,
+        width = PLOT_WIDTH - 20
+    )
+    .unwrap();
+    write!(labels, "{:>10.2}", maxima).unwrap();
+    labels
+}
 
 pub(crate) fn render_plot(minima: f64, q1: f64, median: f64, q3: f64, maxima: f64) -> String {
-    // TODO print axis labels
     let value_range = maxima - minima;
     let quartile_0 = q1 - minima;
     let quartile_1 = median - q1;
@@ -20,6 +35,10 @@ pub(crate) fn render_plot(minima: f64, q1: f64, median: f64, q3: f64, maxima: f6
     plot.push_str("-".repeat((quartile_3 * scale_factor) as usize).as_str());
     plot.push('|');
 
+    let axis_labels = generate_axis_labels(minima, maxima);
+    plot.push('\n');
+    plot.push_str(&axis_labels);
+
     log::debug!("fn input: {minima}, {q1}, {median}, {q3}, {maxima}");
     log::debug!("quartiles: {quartile_0}, {quartile_1}, {quartile_2}, {quartile_3}");
     log::debug!("value range: {value_range}");