Histograms with a configurable number of buckets, and a terminal-friendly
Display.
This crate provides a Histogram type that allows configuration of the number
of buckets that will be used, regardless of the range of input samples. This is
useful when displaying a Histogram (for example, when printing it to a
terminal) but it sacrifices fancy tracking of precision and significant figures.
It uses O(n) memory.
extern crate histo;
use histo::Histogram;
// Create a histogram that will have 10 buckets.
let mut histogram = Histogram::with_buckets(10);
// Adds some samples to the histogram.
for sample in 0..100 {
histogram.add(sample);
histogram.add(sample * sample);
}
// Iterate over buckets and do stuff with their range and count.
for bucket in histogram.buckets() {
do_stuff(bucket.start(), bucket.end(), bucket.count());
}
// And you can also `Display` a histogram!
println!("{}", histogram);
// Prints:
//
// ```
// # Number of samples = 200
// # Min = 0
// # Max = 9801
// #
// # Mean = 1666.5000000000005
// # Standard deviation = 2641.2281518263426
// # Variance = 6976086.1499999985
// #
// # Each ∎ is a count of 2
// #
// 0 .. 980 [ 132 ]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
// 980 .. 1960 [ 13 ]: ∎∎∎∎∎∎
// 1960 .. 2940 [ 10 ]: ∎∎∎∎∎
// 2940 .. 3920 [ 8 ]: ∎∎∎∎
// 3920 .. 4900 [ 7 ]: ∎∎∎
// 4900 .. 5880 [ 7 ]: ∎∎∎
// 5880 .. 6860 [ 6 ]: ∎∎∎
// 6860 .. 7840 [ 6 ]: ∎∎∎
// 7840 .. 8820 [ 5 ]: ∎∎
// 8820 .. 9800 [ 6 ]: ∎∎∎
// ```To use the histo crate in your Rust project, add it to your Cargo.toml file:
[dependencies]
histo = "0.1.0"The histo crate also comes with the command line histo tool:
$ cargo install histo
$ tail samples.txt
1
2
3
4
5
1
2
3
4
5
$ histo < samples.txt
# Number of samples = 150
# Min = 1
# Max = 10
#
# Mean = 5.833333333333334
# Standard deviation = 1.9301698255737905
# Variance = 3.7255555555555566
#
# Each ∎ is a count of 1
#
1 .. 2 [ 3 ]: ∎∎∎
2 .. 3 [ 3 ]: ∎∎∎
3 .. 4 [ 3 ]: ∎∎∎
4 .. 5 [ 31 ]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
5 .. 6 [ 28 ]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
6 .. 7 [ 29 ]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
7 .. 8 [ 29 ]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
8 .. 9 [ 8 ]: ∎∎∎∎∎∎∎∎
9 .. 10 [ 8 ]: ∎∎∎∎∎∎∎∎
10 .. 11 [ 8 ]: ∎∎∎∎∎∎∎∎