Crate histo_fp

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_fp;
use histo_fp::Histogram;

// Create a histogram that will have 10 buckets.
let mut histogram = Histogram::with_buckets(10, Some(2));

// Adds some samples to the histogram.
for sample in 0..100 {
    histogram.add(sample as f64);
    histogram.add((sample * sample) as f64);
}

// 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 ]: ∎∎∎
// ```

Structs

• Bucket
  A bucket is a range of samples and their count.
• Buckets
  An iterator over the buckets in a histogram.
• Histogram
  A histogram is a collection of samples, sorted into buckets.