lognplot 0.1.0

Log and plot data
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93

//! Log samples of scalar values.
//!
//! This module enables logging of scalar values.

use super::Metrics;

/// A simple scalar value.
#[derive(Clone, Debug)]
pub struct Sample {
    pub value: f64,
}

impl Sample {
    pub fn new(value: f64) -> Self {
        Sample { value }
    }
}

/// Metrics collected about a certain trace
/// This can be used during query.
#[derive(Debug, Clone)]
pub struct SampleMetrics {
    /// The minimum value of all samples
    pub min: f64,

    /// The maximum value of all samples
    pub max: f64,

    /// The sum of all values. Together with the count, this
    /// allows to calculate the average value.
    pub sum: f64,

    /// This value allows for calculation of the variance of the
    /// signal.
    /// TODO: this value will be insanely large at some point
    /// in time.
    pub sum_squared: f64,

    /// The total number of samples
    pub count: usize,
}

impl SampleMetrics {
    pub fn new(min: f64, max: f64, sum: f64, sum_squared: f64, count: usize) -> Self {
        SampleMetrics {
            min,
            max,
            sum,
            sum_squared,
            count,
        }
    }

    /// Calculate the mean value of this metrics.
    pub fn mean(&self) -> f64 {
        self.sum / (self.count as f64)
    }
}

impl From<Sample> for SampleMetrics {
    fn from(sample: Sample) -> Self {
        SampleMetrics {
            min: sample.value,
            max: sample.value,
            sum: sample.value,
            sum_squared: sample.value * sample.value,
            count: 1,
        }
    }
}

impl Metrics<Sample> for SampleMetrics {
    /// Integrate a single sample into tha metrics.
    /// This involves updating the min and max values
    /// as well as the count and the sum.
    fn update(&mut self, sample: &Sample) {
        self.min = self.min.min(sample.value);
        self.max = self.max.max(sample.value);

        self.sum += sample.value;
        self.sum_squared += sample.value * sample.value;
        self.count += 1;
    }

    /// Include other metrics into this metrics.
    fn include(&mut self, metrics: &SampleMetrics) {
        self.min = self.min.min(metrics.min);
        self.max = self.max.max(metrics.max);
        self.count += metrics.count;
        self.sum += metrics.sum;
        self.sum_squared += metrics.sum_squared;
    }
}