rust/src/libextra/stats.rs
2013-08-16 15:41:28 +10:00

953 lines
28 KiB
Rust

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use sort;
use std::cmp;
use std::hashmap;
use std::io;
use std::num;
// NB: this can probably be rewritten in terms of num::Num
// to be less f64-specific.
/// Trait that provides simple descriptive statistics on a univariate set of numeric samples.
pub trait Stats {
/// Sum of the samples.
fn sum(self) -> f64;
/// Minimum value of the samples.
fn min(self) -> f64;
/// Maximum value of the samples.
fn max(self) -> f64;
/// Arithmetic mean (average) of the samples: sum divided by sample-count.
///
/// See: https://en.wikipedia.org/wiki/Arithmetic_mean
fn mean(self) -> f64;
/// Median of the samples: value separating the lower half of the samples from the higher half.
/// Equal to `self.percentile(50.0)`.
///
/// See: https://en.wikipedia.org/wiki/Median
fn median(self) -> f64;
/// Variance of the samples: bias-corrected mean of the squares of the differences of each
/// sample from the sample mean. Note that this calculates the _sample variance_ rather than the
/// population variance, which is assumed to be unknown. It therefore corrects the `(n-1)/n`
/// bias that would appear if we calculated a population variance, by dividing by `(n-1)` rather
/// than `n`.
///
/// See: https://en.wikipedia.org/wiki/Variance
fn var(self) -> f64;
/// Standard deviation: the square root of the sample variance.
///
/// Note: this is not a robust statistic for non-normal distributions. Prefer the
/// `median_abs_dev` for unknown distributions.
///
/// See: https://en.wikipedia.org/wiki/Standard_deviation
fn std_dev(self) -> f64;
/// Standard deviation as a percent of the mean value. See `std_dev` and `mean`.
///
/// Note: this is not a robust statistic for non-normal distributions. Prefer the
/// `median_abs_dev_pct` for unknown distributions.
fn std_dev_pct(self) -> f64;
/// Scaled median of the absolute deviations of each sample from the sample median. This is a
/// robust (distribution-agnostic) estimator of sample variability. Use this in preference to
/// `std_dev` if you cannot assume your sample is normally distributed. Note that this is scaled
/// by the constant `1.4826` to allow its use as a consistent estimator for the standard
/// deviation.
///
/// See: http://en.wikipedia.org/wiki/Median_absolute_deviation
fn median_abs_dev(self) -> f64;
/// Median absolute deviation as a percent of the median. See `median_abs_dev` and `median`.
fn median_abs_dev_pct(self) -> f64;
/// Percentile: the value below which `pct` percent of the values in `self` fall. For example,
/// percentile(95.0) will return the value `v` such that that 95% of the samples `s` in `self`
/// satisfy `s <= v`.
///
/// Calculated by linear interpolation between closest ranks.
///
/// See: http://en.wikipedia.org/wiki/Percentile
fn percentile(self, pct: f64) -> f64;
/// Quartiles of the sample: three values that divide the sample into four equal groups, each
/// with 1/4 of the data. The middle value is the median. See `median` and `percentile`. This
/// function may calculate the 3 quartiles more efficiently than 3 calls to `percentile`, but
/// is otherwise equivalent.
///
/// See also: https://en.wikipedia.org/wiki/Quartile
fn quartiles(self) -> (f64,f64,f64);
/// Inter-quartile range: the difference between the 25th percentile (1st quartile) and the 75th
/// percentile (3rd quartile). See `quartiles`.
///
/// See also: https://en.wikipedia.org/wiki/Interquartile_range
fn iqr(self) -> f64;
}
/// Extracted collection of all the summary statistics of a sample set.
#[deriving(Clone, Eq)]
struct Summary {
sum: f64,
min: f64,
max: f64,
mean: f64,
median: f64,
var: f64,
std_dev: f64,
std_dev_pct: f64,
median_abs_dev: f64,
median_abs_dev_pct: f64,
quartiles: (f64,f64,f64),
iqr: f64,
}
impl Summary {
/// Construct a new summary of a sample set.
pub fn new(samples: &[f64]) -> Summary {
Summary {
sum: samples.sum(),
min: samples.min(),
max: samples.max(),
mean: samples.mean(),
median: samples.median(),
var: samples.var(),
std_dev: samples.std_dev(),
std_dev_pct: samples.std_dev_pct(),
median_abs_dev: samples.median_abs_dev(),
median_abs_dev_pct: samples.median_abs_dev_pct(),
quartiles: samples.quartiles(),
iqr: samples.iqr()
}
}
}
impl<'self> Stats for &'self [f64] {
fn sum(self) -> f64 {
self.iter().fold(0.0, |p,q| p + *q)
}
fn min(self) -> f64 {
assert!(self.len() != 0);
self.iter().fold(self[0], |p,q| cmp::min(p, *q))
}
fn max(self) -> f64 {
assert!(self.len() != 0);
self.iter().fold(self[0], |p,q| cmp::max(p, *q))
}
fn mean(self) -> f64 {
assert!(self.len() != 0);
self.sum() / (self.len() as f64)
}
fn median(self) -> f64 {
self.percentile(50.0)
}
fn var(self) -> f64 {
if self.len() < 2 {
0.0
} else {
let mean = self.mean();
let mut v = 0.0;
for s in self.iter() {
let x = *s - mean;
v += x*x;
}
// NB: this is _supposed to be_ len-1, not len. If you
// change it back to len, you will be calculating a
// population variance, not a sample variance.
v/((self.len()-1) as f64)
}
}
fn std_dev(self) -> f64 {
self.var().sqrt()
}
fn std_dev_pct(self) -> f64 {
(self.std_dev() / self.mean()) * 100.0
}
fn median_abs_dev(self) -> f64 {
let med = self.median();
let abs_devs = self.map(|&v| num::abs(med - v));
// This constant is derived by smarter statistics brains than me, but it is
// consistent with how R and other packages treat the MAD.
abs_devs.median() * 1.4826
}
fn median_abs_dev_pct(self) -> f64 {
(self.median_abs_dev() / self.median()) * 100.0
}
fn percentile(self, pct: f64) -> f64 {
let mut tmp = self.to_owned();
sort::tim_sort(tmp);
percentile_of_sorted(tmp, pct)
}
fn quartiles(self) -> (f64,f64,f64) {
let mut tmp = self.to_owned();
sort::tim_sort(tmp);
let a = percentile_of_sorted(tmp, 25.0);
let b = percentile_of_sorted(tmp, 50.0);
let c = percentile_of_sorted(tmp, 75.0);
(a,b,c)
}
fn iqr(self) -> f64 {
let (a,_,c) = self.quartiles();
c - a
}
}
// Helper function: extract a value representing the `pct` percentile of a sorted sample-set, using
// linear interpolation. If samples are not sorted, return nonsensical value.
fn percentile_of_sorted(sorted_samples: &[f64],
pct: f64) -> f64 {
assert!(sorted_samples.len() != 0);
if sorted_samples.len() == 1 {
return sorted_samples[0];
}
assert!(0.0 <= pct);
assert!(pct <= 100.0);
if pct == 100.0 {
return sorted_samples[sorted_samples.len() - 1];
}
let rank = (pct / 100.0) * ((sorted_samples.len() - 1) as f64);
let lrank = rank.floor();
let d = rank - lrank;
let n = lrank as uint;
let lo = sorted_samples[n];
let hi = sorted_samples[n+1];
lo + (hi - lo) * d
}
/// Winsorize a set of samples, replacing values above the `100-pct` percentile and below the `pct`
/// percentile with those percentiles themselves. This is a way of minimizing the effect of
/// outliers, at the cost of biasing the sample. It differs from trimming in that it does not
/// change the number of samples, just changes the values of those that are outliers.
///
/// See: http://en.wikipedia.org/wiki/Winsorising
pub fn winsorize(samples: &mut [f64], pct: f64) {
let mut tmp = samples.to_owned();
sort::tim_sort(tmp);
let lo = percentile_of_sorted(tmp, pct);
let hi = percentile_of_sorted(tmp, 100.0-pct);
for samp in samples.mut_iter() {
if *samp > hi {
*samp = hi
} else if *samp < lo {
*samp = lo
}
}
}
/// Render writes the min, max and quartiles of the provided `Summary` to the provided `Writer`.
pub fn write_5_number_summary(w: @io::Writer, s: &Summary) {
let (q1,q2,q3) = s.quartiles;
w.write_str(fmt!("(min=%f, q1=%f, med=%f, q3=%f, max=%f)",
s.min as float,
q1 as float,
q2 as float,
q3 as float,
s.max as float));
}
/// Render a boxplot to the provided writer. The boxplot shows the min, max and quartiles of the
/// provided `Summary` (thus includes the mean) and is scaled to display within the range of the
/// nearest multiple-of-a-power-of-ten above and below the min and max of possible values, and
/// target `width_hint` characters of display (though it will be wider if necessary).
///
/// As an example, the summary with 5-number-summary `(min=15, q1=17, med=20, q3=24, max=31)` might
/// display as:
///
/// ~~~~
/// 10 | [--****#******----------] | 40
/// ~~~~
pub fn write_boxplot(w: @io::Writer, s: &Summary, width_hint: uint) {
let (q1,q2,q3) = s.quartiles;
// the .abs() handles the case where numbers are negative
let lomag = (10.0_f64).pow(&(s.min.abs().log10().floor()));
let himag = (10.0_f64).pow(&(s.max.abs().log10().floor()));
// need to consider when the limit is zero
let lo = if lomag == 0.0 {
0.0
} else {
(s.min / lomag).floor() * lomag
};
let hi = if himag == 0.0 {
0.0
} else {
(s.max / himag).ceil() * himag
};
let range = hi - lo;
let lostr = lo.to_str();
let histr = hi.to_str();
let overhead_width = lostr.len() + histr.len() + 4;
let range_width = width_hint - overhead_width;;
let char_step = range / (range_width as f64);
w.write_str(lostr);
w.write_char(' ');
w.write_char('|');
let mut c = 0;
let mut v = lo;
while c < range_width && v < s.min {
w.write_char(' ');
v += char_step;
c += 1;
}
w.write_char('[');
c += 1;
while c < range_width && v < q1 {
w.write_char('-');
v += char_step;
c += 1;
}
while c < range_width && v < q2 {
w.write_char('*');
v += char_step;
c += 1;
}
w.write_char('#');
c += 1;
while c < range_width && v < q3 {
w.write_char('*');
v += char_step;
c += 1;
}
while c < range_width && v < s.max {
w.write_char('-');
v += char_step;
c += 1;
}
w.write_char(']');
while c < range_width {
w.write_char(' ');
v += char_step;
c += 1;
}
w.write_char('|');
w.write_char(' ');
w.write_str(histr);
}
/// Returns a HashMap with the number of occurrences of every element in the
/// sequence that the iterator exposes.
pub fn freq_count<T: Iterator<U>, U: Eq+Hash>(mut iter: T) -> hashmap::HashMap<U, uint> {
let mut map = hashmap::HashMap::new::<U, uint>();
for elem in iter {
map.insert_or_update_with(elem, 1, |_, count| *count += 1);
}
map
}
// Test vectors generated from R, using the script src/etc/stat-test-vectors.r.
#[cfg(test)]
mod tests {
use stats::Stats;
use stats::Summary;
use stats::write_5_number_summary;
use stats::write_boxplot;
use std::io;
fn check(samples: &[f64], summ: &Summary) {
let summ2 = Summary::new(samples);
let w = io::stdout();
w.write_char('\n');
write_5_number_summary(w, &summ2);
w.write_char('\n');
write_boxplot(w, &summ2, 50);
w.write_char('\n');
assert_eq!(summ.sum, summ2.sum);
assert_eq!(summ.min, summ2.min);
assert_eq!(summ.max, summ2.max);
assert_eq!(summ.mean, summ2.mean);
assert_eq!(summ.median, summ2.median);
// We needed a few more digits to get exact equality on these
// but they're within float epsilon, which is 1.0e-6.
assert_approx_eq!(summ.var, summ2.var);
assert_approx_eq!(summ.std_dev, summ2.std_dev);
assert_approx_eq!(summ.std_dev_pct, summ2.std_dev_pct);
assert_approx_eq!(summ.median_abs_dev, summ2.median_abs_dev);
assert_approx_eq!(summ.median_abs_dev_pct, summ2.median_abs_dev_pct);
assert_eq!(summ.quartiles, summ2.quartiles);
assert_eq!(summ.iqr, summ2.iqr);
}
#[test]
fn test_norm2() {
let val = &[
958.0000000000,
924.0000000000,
];
let summ = &Summary {
sum: 1882.0000000000,
min: 924.0000000000,
max: 958.0000000000,
mean: 941.0000000000,
median: 941.0000000000,
var: 578.0000000000,
std_dev: 24.0416305603,
std_dev_pct: 2.5549022912,
median_abs_dev: 25.2042000000,
median_abs_dev_pct: 2.6784484591,
quartiles: (932.5000000000,941.0000000000,949.5000000000),
iqr: 17.0000000000,
};
check(val, summ);
}
#[test]
fn test_norm10narrow() {
let val = &[
966.0000000000,
985.0000000000,
1110.0000000000,
848.0000000000,
821.0000000000,
975.0000000000,
962.0000000000,
1157.0000000000,
1217.0000000000,
955.0000000000,
];
let summ = &Summary {
sum: 9996.0000000000,
min: 821.0000000000,
max: 1217.0000000000,
mean: 999.6000000000,
median: 970.5000000000,
var: 16050.7111111111,
std_dev: 126.6914010938,
std_dev_pct: 12.6742097933,
median_abs_dev: 102.2994000000,
median_abs_dev_pct: 10.5408964451,
quartiles: (956.7500000000,970.5000000000,1078.7500000000),
iqr: 122.0000000000,
};
check(val, summ);
}
#[test]
fn test_norm10medium() {
let val = &[
954.0000000000,
1064.0000000000,
855.0000000000,
1000.0000000000,
743.0000000000,
1084.0000000000,
704.0000000000,
1023.0000000000,
357.0000000000,
869.0000000000,
];
let summ = &Summary {
sum: 8653.0000000000,
min: 357.0000000000,
max: 1084.0000000000,
mean: 865.3000000000,
median: 911.5000000000,
var: 48628.4555555556,
std_dev: 220.5186059170,
std_dev_pct: 25.4846418487,
median_abs_dev: 195.7032000000,
median_abs_dev_pct: 21.4704552935,
quartiles: (771.0000000000,911.5000000000,1017.2500000000),
iqr: 246.2500000000,
};
check(val, summ);
}
#[test]
fn test_norm10wide() {
let val = &[
505.0000000000,
497.0000000000,
1591.0000000000,
887.0000000000,
1026.0000000000,
136.0000000000,
1580.0000000000,
940.0000000000,
754.0000000000,
1433.0000000000,
];
let summ = &Summary {
sum: 9349.0000000000,
min: 136.0000000000,
max: 1591.0000000000,
mean: 934.9000000000,
median: 913.5000000000,
var: 239208.9888888889,
std_dev: 489.0899599142,
std_dev_pct: 52.3146817750,
median_abs_dev: 611.5725000000,
median_abs_dev_pct: 66.9482758621,
quartiles: (567.2500000000,913.5000000000,1331.2500000000),
iqr: 764.0000000000,
};
check(val, summ);
}
#[test]
fn test_norm25verynarrow() {
let val = &[
991.0000000000,
1018.0000000000,
998.0000000000,
1013.0000000000,
974.0000000000,
1007.0000000000,
1014.0000000000,
999.0000000000,
1011.0000000000,
978.0000000000,
985.0000000000,
999.0000000000,
983.0000000000,
982.0000000000,
1015.0000000000,
1002.0000000000,
977.0000000000,
948.0000000000,
1040.0000000000,
974.0000000000,
996.0000000000,
989.0000000000,
1015.0000000000,
994.0000000000,
1024.0000000000,
];
let summ = &Summary {
sum: 24926.0000000000,
min: 948.0000000000,
max: 1040.0000000000,
mean: 997.0400000000,
median: 998.0000000000,
var: 393.2066666667,
std_dev: 19.8294393937,
std_dev_pct: 1.9888308788,
median_abs_dev: 22.2390000000,
median_abs_dev_pct: 2.2283567134,
quartiles: (983.0000000000,998.0000000000,1013.0000000000),
iqr: 30.0000000000,
};
check(val, summ);
}
#[test]
fn test_exp10a() {
let val = &[
23.0000000000,
11.0000000000,
2.0000000000,
57.0000000000,
4.0000000000,
12.0000000000,
5.0000000000,
29.0000000000,
3.0000000000,
21.0000000000,
];
let summ = &Summary {
sum: 167.0000000000,
min: 2.0000000000,
max: 57.0000000000,
mean: 16.7000000000,
median: 11.5000000000,
var: 287.7888888889,
std_dev: 16.9643416875,
std_dev_pct: 101.5828843560,
median_abs_dev: 13.3434000000,
median_abs_dev_pct: 116.0295652174,
quartiles: (4.2500000000,11.5000000000,22.5000000000),
iqr: 18.2500000000,
};
check(val, summ);
}
#[test]
fn test_exp10b() {
let val = &[
24.0000000000,
17.0000000000,
6.0000000000,
38.0000000000,
25.0000000000,
7.0000000000,
51.0000000000,
2.0000000000,
61.0000000000,
32.0000000000,
];
let summ = &Summary {
sum: 263.0000000000,
min: 2.0000000000,
max: 61.0000000000,
mean: 26.3000000000,
median: 24.5000000000,
var: 383.5666666667,
std_dev: 19.5848580967,
std_dev_pct: 74.4671410520,
median_abs_dev: 22.9803000000,
median_abs_dev_pct: 93.7971428571,
quartiles: (9.5000000000,24.5000000000,36.5000000000),
iqr: 27.0000000000,
};
check(val, summ);
}
#[test]
fn test_exp10c() {
let val = &[
71.0000000000,
2.0000000000,
32.0000000000,
1.0000000000,
6.0000000000,
28.0000000000,
13.0000000000,
37.0000000000,
16.0000000000,
36.0000000000,
];
let summ = &Summary {
sum: 242.0000000000,
min: 1.0000000000,
max: 71.0000000000,
mean: 24.2000000000,
median: 22.0000000000,
var: 458.1777777778,
std_dev: 21.4050876611,
std_dev_pct: 88.4507754589,
median_abs_dev: 21.4977000000,
median_abs_dev_pct: 97.7168181818,
quartiles: (7.7500000000,22.0000000000,35.0000000000),
iqr: 27.2500000000,
};
check(val, summ);
}
#[test]
fn test_exp25() {
let val = &[
3.0000000000,
24.0000000000,
1.0000000000,
19.0000000000,
7.0000000000,
5.0000000000,
30.0000000000,
39.0000000000,
31.0000000000,
13.0000000000,
25.0000000000,
48.0000000000,
1.0000000000,
6.0000000000,
42.0000000000,
63.0000000000,
2.0000000000,
12.0000000000,
108.0000000000,
26.0000000000,
1.0000000000,
7.0000000000,
44.0000000000,
25.0000000000,
11.0000000000,
];
let summ = &Summary {
sum: 593.0000000000,
min: 1.0000000000,
max: 108.0000000000,
mean: 23.7200000000,
median: 19.0000000000,
var: 601.0433333333,
std_dev: 24.5161851301,
std_dev_pct: 103.3565983562,
median_abs_dev: 19.2738000000,
median_abs_dev_pct: 101.4410526316,
quartiles: (6.0000000000,19.0000000000,31.0000000000),
iqr: 25.0000000000,
};
check(val, summ);
}
#[test]
fn test_binom25() {
let val = &[
18.0000000000,
17.0000000000,
27.0000000000,
15.0000000000,
21.0000000000,
25.0000000000,
17.0000000000,
24.0000000000,
25.0000000000,
24.0000000000,
26.0000000000,
26.0000000000,
23.0000000000,
15.0000000000,
23.0000000000,
17.0000000000,
18.0000000000,
18.0000000000,
21.0000000000,
16.0000000000,
15.0000000000,
31.0000000000,
20.0000000000,
17.0000000000,
15.0000000000,
];
let summ = &Summary {
sum: 514.0000000000,
min: 15.0000000000,
max: 31.0000000000,
mean: 20.5600000000,
median: 20.0000000000,
var: 20.8400000000,
std_dev: 4.5650848842,
std_dev_pct: 22.2037202539,
median_abs_dev: 5.9304000000,
median_abs_dev_pct: 29.6520000000,
quartiles: (17.0000000000,20.0000000000,24.0000000000),
iqr: 7.0000000000,
};
check(val, summ);
}
#[test]
fn test_pois25lambda30() {
let val = &[
27.0000000000,
33.0000000000,
34.0000000000,
34.0000000000,
24.0000000000,
39.0000000000,
28.0000000000,
27.0000000000,
31.0000000000,
28.0000000000,
38.0000000000,
21.0000000000,
33.0000000000,
36.0000000000,
29.0000000000,
37.0000000000,
32.0000000000,
34.0000000000,
31.0000000000,
39.0000000000,
25.0000000000,
31.0000000000,
32.0000000000,
40.0000000000,
24.0000000000,
];
let summ = &Summary {
sum: 787.0000000000,
min: 21.0000000000,
max: 40.0000000000,
mean: 31.4800000000,
median: 32.0000000000,
var: 26.5933333333,
std_dev: 5.1568724372,
std_dev_pct: 16.3814245145,
median_abs_dev: 5.9304000000,
median_abs_dev_pct: 18.5325000000,
quartiles: (28.0000000000,32.0000000000,34.0000000000),
iqr: 6.0000000000,
};
check(val, summ);
}
#[test]
fn test_pois25lambda40() {
let val = &[
42.0000000000,
50.0000000000,
42.0000000000,
46.0000000000,
34.0000000000,
45.0000000000,
34.0000000000,
49.0000000000,
39.0000000000,
28.0000000000,
40.0000000000,
35.0000000000,
37.0000000000,
39.0000000000,
46.0000000000,
44.0000000000,
32.0000000000,
45.0000000000,
42.0000000000,
37.0000000000,
48.0000000000,
42.0000000000,
33.0000000000,
42.0000000000,
48.0000000000,
];
let summ = &Summary {
sum: 1019.0000000000,
min: 28.0000000000,
max: 50.0000000000,
mean: 40.7600000000,
median: 42.0000000000,
var: 34.4400000000,
std_dev: 5.8685603004,
std_dev_pct: 14.3978417577,
median_abs_dev: 5.9304000000,
median_abs_dev_pct: 14.1200000000,
quartiles: (37.0000000000,42.0000000000,45.0000000000),
iqr: 8.0000000000,
};
check(val, summ);
}
#[test]
fn test_pois25lambda50() {
let val = &[
45.0000000000,
43.0000000000,
44.0000000000,
61.0000000000,
51.0000000000,
53.0000000000,
59.0000000000,
52.0000000000,
49.0000000000,
51.0000000000,
51.0000000000,
50.0000000000,
49.0000000000,
56.0000000000,
42.0000000000,
52.0000000000,
51.0000000000,
43.0000000000,
48.0000000000,
48.0000000000,
50.0000000000,
42.0000000000,
43.0000000000,
42.0000000000,
60.0000000000,
];
let summ = &Summary {
sum: 1235.0000000000,
min: 42.0000000000,
max: 61.0000000000,
mean: 49.4000000000,
median: 50.0000000000,
var: 31.6666666667,
std_dev: 5.6273143387,
std_dev_pct: 11.3913245723,
median_abs_dev: 4.4478000000,
median_abs_dev_pct: 8.8956000000,
quartiles: (44.0000000000,50.0000000000,52.0000000000),
iqr: 8.0000000000,
};
check(val, summ);
}
#[test]
fn test_unif25() {
let val = &[
99.0000000000,
55.0000000000,
92.0000000000,
79.0000000000,
14.0000000000,
2.0000000000,
33.0000000000,
49.0000000000,
3.0000000000,
32.0000000000,
84.0000000000,
59.0000000000,
22.0000000000,
86.0000000000,
76.0000000000,
31.0000000000,
29.0000000000,
11.0000000000,
41.0000000000,
53.0000000000,
45.0000000000,
44.0000000000,
98.0000000000,
98.0000000000,
7.0000000000,
];
let summ = &Summary {
sum: 1242.0000000000,
min: 2.0000000000,
max: 99.0000000000,
mean: 49.6800000000,
median: 45.0000000000,
var: 1015.6433333333,
std_dev: 31.8691595957,
std_dev_pct: 64.1488719719,
median_abs_dev: 45.9606000000,
median_abs_dev_pct: 102.1346666667,
quartiles: (29.0000000000,45.0000000000,79.0000000000),
iqr: 50.0000000000,
};
check(val, summ);
}
#[test]
fn test_boxplot_nonpositive() {
fn t(s: &Summary, expected: ~str) {
let out = do io::with_str_writer |w| {
write_boxplot(w, s, 30)
};
assert_eq!(out, expected);
}
t(&Summary::new([-2.0, -1.0]), ~"-2 |[------******#*****---]| -1");
t(&Summary::new([0.0, 2.0]), ~"0 |[-------*****#*******---]| 2");
t(&Summary::new([-2.0, 0.0]), ~"-2 |[------******#******---]| 0");
}
}