Merge pull request #59 from JackKCWong/main

add percentiles to summary output

Cargo.toml

@@ -41,3 +41,4 @@ tempfile = "3"
 assert_cmd = "^2"
 predicates = "^3"
 serial_test = "2"
+rand = "0.8.5"

src/lib.rs

@@ -8,7 +8,7 @@
 //! ```rust,no_run
 //! use lowcharts::plot;
 //!
-//! let vec = &[-1.0, -1.1, 2.0, 2.0, 2.1, -0.9, 11.0, 11.2, 1.9, 1.99];
+//! let vec = &mut [-1.0, -1.1, 2.0, 2.0, 2.1, -0.9, 11.0, 11.2, 1.9, 1.99];
 //! // Plot a histogram of the above vector, with 4 buckets and a precision
 //! // chosen by library
 //! let options = plot::HistogramOptions { intervals: 4, ..Default::default() };

src/main.rs

@@ -105,7 +105,7 @@ fn histogram(matches: &ArgMatches) -> i32 {
         Ok(r) => r,
         _ => return 2,
     };
-    let vec = reader.read(matches.value_of("input").unwrap());
+    let mut vec = reader.read(matches.value_of("input").unwrap());
     if !assert_data(&vec, 1) {
         return 1;
     }
@@ -117,7 +117,7 @@ fn histogram(matches: &ArgMatches) -> i32 {
     options.log_scale = matches.is_present("log-scale");
     options.intervals = matches.value_of_t("intervals").unwrap();
     let width = matches.value_of_t("width").unwrap();
-    let histogram = plot::Histogram::new(&vec, options);
+    let histogram = plot::Histogram::new(&mut vec, options);
     print!("{histogram:width$}");
     0
 }

src/plot/histogram.rs

@@ -54,7 +54,7 @@ impl Histogram {
     ///
     /// `options` is a `HistogramOptions` struct with the preferences to create
     /// histogram.
-    pub fn new(vec: &[f64], mut options: HistogramOptions) -> Self {
+    pub fn new(vec: &mut [f64], mut options: HistogramOptions) -> Self {
         let mut stats = Stats::new(vec, options.precision);
         if options.log_scale {
             stats.min = 0.0; // We will silently discard negative values
@@ -222,7 +222,7 @@ mod tests {
 
     #[test]
     fn test_buckets() {
-        let stats = Stats::new(&[-2.0, 14.0], None);
+        let stats = Stats::new(&mut [-2.0, 14.0], None);
         let options = HistogramOptions {
             intervals: 8,
             ..Default::default()
@@ -247,14 +247,14 @@ mod tests {
             intervals: 6,
             ..Default::default()
         };
-        let mut hist = Histogram::new_with_stats(Stats::new(&[-2.0, 4.0], None), &options);
+        let mut hist = Histogram::new_with_stats(Stats::new(&mut [-2.0, 4.0], None), &options);
         hist.load(&[-1.0, 2.0, -1.0, 2.0, 10.0, 10.0, 10.0, -10.0]);
         assert_eq!(hist.top, 2);
     }
 
     #[test]
     fn display_test() {
-        let stats = Stats::new(&[-2.0, 14.0], None);
+        let stats = Stats::new(&mut [-2.0, 14.0], None);
         let options = HistogramOptions {
             intervals: 8,
             precision: Some(3),
@@ -280,7 +280,7 @@ mod tests {
             precision: Some(3),
             ..Default::default()
         };
-        let mut hist = Histogram::new_with_stats(Stats::new(&[-2.0, 14.0], None), &options);
+        let mut hist = Histogram::new_with_stats(Stats::new(&mut [-2.0, 14.0], None), &options);
         hist.load(&[
             -1.0, -1.1, 2.0, 2.0, 2.1, -0.9, 11.0, 11.2, 1.9, 1.99, 1.98, 1.97, 1.96,
         ]);
@@ -291,7 +291,7 @@ mod tests {
 
     #[test]
     fn display_test_human_units() {
-        let vector = &[
+        let vector = &mut [
             -1.0,
             -12000000.0,
             -12000001.0,
@@ -320,7 +320,7 @@ mod tests {
     #[test]
     fn display_test_log_scale() {
         let hist = Histogram::new(
-            &[0.4, 0.4, 0.4, 0.4, 255.0, 0.2, 1.2, 128.0, 126.0, -7.0],
+            &mut [0.4, 0.4, 0.4, 0.4, 255.0, 0.2, 1.2, 128.0, 126.0, -7.0],
             HistogramOptions {
                 intervals: 8,
                 log_scale: true,
@@ -402,7 +402,7 @@ mod tests {
             intervals: 8,
             ..Default::default()
         };
-        let hist = Histogram::new_with_stats(Stats::new(&[-12.0, 4.0], None), &options);
+        let hist = Histogram::new_with_stats(Stats::new(&mut [-12.0, 4.0], None), &options);
         assert!(hist.find_slot(-13.0) == None);
         assert!(hist.find_slot(13.0) == None);
         assert!(hist.find_slot(-12.0) == Some(0));
@@ -416,7 +416,7 @@ mod tests {
     fn find_slot_logarithmic() {
         let hist = Histogram::new(
             // More than 8 values to avoid interval truncation
-            &[255.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -2000.0],
+            &mut [255.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, -2000.0],
             HistogramOptions {
                 intervals: 8,
                 log_scale: true,

src/plot/xy.rs

@@ -1,3 +1,4 @@
+use std::borrow::BorrowMut;
 use std::fmt;
 use std::ops::Range;
 
@@ -32,7 +33,12 @@ impl XyPlot {
     /// "None" is used, human units will be used, with an heuristic based on the
     /// input data for deciding the units and the decimal places.
     pub fn new(vec: &[f64], width: usize, height: usize, precision: Option<usize>) -> Self {
-        let mut plot = Self::new_with_stats(width, height, Stats::new(vec, precision), precision);
+        let mut plot = Self::new_with_stats(
+            width,
+            height,
+            Stats::new(vec.to_vec().borrow_mut(), precision),
+            precision,
+        );
         plot.load(vec);
         plot
     }
@@ -132,7 +138,7 @@ mod tests {
 
     #[test]
     fn basic_test() {
-        let stats = Stats::new(&[-1.0, 4.0], None);
+        let stats = Stats::new(&mut [-1.0, 4.0], None);
         let mut plot = XyPlot::new_with_stats(3, 5, stats, Some(3));
         plot.load(&[-1.0, 0.0, 1.0, 2.0, 3.0, 4.0, -1.0]);
         assert_float_eq!(plot.x_axis[0], -0.5, rmax <= f64::EPSILON);
@@ -146,7 +152,7 @@ mod tests {
 
     #[test]
     fn display_test() {
-        let stats = Stats::new(&[-1.0, 4.0], None);
+        let stats = Stats::new(&mut [-1.0, 4.0], None);
         let mut plot = XyPlot::new_with_stats(3, 5, stats, Some(3));
         plot.load(&[-1.0, 0.0, 1.0, 2.0, 3.0, 4.0, -1.0]);
         Paint::disable();
@@ -159,7 +165,7 @@ mod tests {
 
     #[test]
     fn display_test_human_units() {
-        let vector = &[1000000.0, -1000000.0, -2000000.0, -4000000.0];
+        let vector = &mut [1000000.0, -1000000.0, -2000000.0, -4000000.0];
         let plot = XyPlot::new(vector, 3, 5, None);
         Paint::disable();
         let display = format!("{plot}");

src/stats/mod.rs

@@ -21,6 +21,27 @@ pub struct Stats {
     /// Number of samples of the input values.
     pub samples: usize,
     precision: Option<usize>, // If None, then human friendly display will be used
+
+    /// 50 percentile
+    pub p50: f64,
+    /// 90 percentile
+    pub p90: f64,
+    /// 95 percentile
+    pub p95: f64,
+    /// 99 percentile
+    pub p99: f64,
+}
+
+fn percentiles(vec: &mut [f64]) -> (f64, f64, f64, f64) {
+    vec.sort_by(|a, b| a.partial_cmp(b).unwrap());
+
+    let len = vec.len();
+    let p50 = vec[len / 2];
+    let p90 = vec[(len * 9) / 10];
+    let p95 = vec[(len * 95) / 100];
+    let p99 = vec[(len * 99) / 100];
+
+    (p50, p90, p95, p99)
 }
 
 impl Stats {
@@ -29,7 +50,7 @@ impl Stats {
     /// `precision` is an Option with the number of decimals to display.  If
     /// "None" is used, human units will be used, with an heuristic based on the
     /// input data for deciding the units and the decimal places.
-    pub fn new(vec: &[f64], precision: Option<usize>) -> Self {
+    pub fn new(vec: &mut [f64], precision: Option<usize>) -> Self {
         let mut max = vec[0];
         let mut min = max;
         let mut temp: f64 = 0.0;
@@ -42,6 +63,7 @@ impl Stats {
         }
         let var = temp / vec.len() as f64;
         let std = var.sqrt();
+        let (p50, p90, p95, p99) = percentiles(vec);
         Self {
             min,
             max,
@@ -50,6 +72,10 @@ impl Stats {
             var,
             samples: vec.len(),
             precision,
+            p50,
+            p90,
+            p95,
+            p99,
         }
     }
 }
@@ -73,6 +99,14 @@ impl fmt::Display for Stats {
             avg = Blue.paint(formatter.format(self.avg)),
             var = Blue.paint(format!("{:.3}", self.var)),
             std = Blue.paint(format!("{:.3}", self.std)),
+        )?;
+        writeln!(
+            f,
+            "p50 = {p50}; p90 = {p90}; p95 = {p95}; p99 = {p99}",
+            p50 = Blue.paint(formatter.format(self.p50)),
+            p90 = Blue.paint(formatter.format(self.p90)),
+            p95 = Blue.paint(formatter.format(self.p95)),
+            p99 = Blue.paint(formatter.format(self.p99)),
         )
     }
 }
@@ -81,11 +115,12 @@ impl fmt::Display for Stats {
 mod tests {
     use super::*;
     use float_eq::assert_float_eq;
+    use rand::{seq::SliceRandom, thread_rng};
     use yansi::Paint;
 
     #[test]
     fn basic_test() {
-        let stats = Stats::new(&[1.1, 3.3, 2.2], Some(3));
+        let stats = Stats::new(&mut [1.1, 3.3, 2.2], Some(3));
         assert_eq!(3_usize, stats.samples);
         assert_float_eq!(stats.avg, 2.2, rmax <= f64::EPSILON);
         assert_float_eq!(stats.min, 1.1, rmax <= f64::EPSILON);
@@ -96,7 +131,7 @@ mod tests {
 
     #[test]
     fn test_display() {
-        let stats = Stats::new(&[1.1, 3.3, 2.2], Some(3));
+        let stats = Stats::new(&mut [1.1, 3.3, 2.2], Some(3));
         Paint::disable();
         let display = format!("{stats}");
         assert!(display.contains("Samples = 3"));
@@ -107,11 +142,25 @@ mod tests {
 
     #[test]
     fn test_big_num() {
-        let stats = Stats::new(&[123456789.1234, 123456788.1234], None);
+        let stats = Stats::new(&mut [123456789.1234, 123456788.1234], None);
         Paint::disable();
         let display = format!("{stats}");
         assert!(display.contains("Samples = 2"));
         assert!(display.contains("Min = 123456788.123"));
         assert!(display.contains("Max = 123456789.123"));
     }
+
+    #[test]
+    fn test_percentile() {
+        let mut vec: Vec<f64> = (0..100).map(|i| i as f64).collect();
+        vec.shuffle(&mut thread_rng());
+        let stats = Stats::new(&mut vec, Some(1));
+        Paint::disable();
+        let display = format!("{stats}");
+        println!("{}", display);
+        assert!(display.contains("p50 = 50.0"));
+        assert!(display.contains("p90 = 90.0"));
+        assert!(display.contains("p95 = 95.0"));
+        assert!(display.contains("p99 = 99.0"));
+    }
 }