Struct IndividualMRChart 

pub struct IndividualMRChart { /* private fields */ }

Individual and Moving Range (I-MR) control chart.

Monitors individual observations (subgroup size = 1) using the moving range of consecutive observations to estimate process variability.

Algorithm

1. Compute moving ranges: MR_i = |x_i - x_{i-1}| for i >= 1.
2. Compute the mean of individual observations (X-bar) and the average moving range (MR-bar).
3. I chart limits: CL = X-bar, UCL/LCL = X-bar +/- E2 * MR-bar.
4. MR chart limits: CL = MR-bar, UCL = D4 * MR-bar, LCL = 0.

Examples

use u_analytics::spc::{IndividualMRChart, ControlChart};

let mut chart = IndividualMRChart::new();
for &x in &[25.0, 25.2, 24.8, 25.1, 24.9, 25.3, 25.0, 24.7] {
    chart.add_sample(&[x]);
}

let limits = chart.control_limits().expect("should have limits after 2+ observations");
assert!(limits.ucl > limits.cl);
assert!(limits.cl > limits.lcl);

Reference

Montgomery, D.C. (2019). Introduction to Statistical Quality Control, 8th ed., Chapter 6: Control Charts for Variables.

Implementations

impl IndividualMRChart

pub fn new() -> Self

Create a new Individual-MR chart.

pub fn mr_limits(&self) -> Option<ControlLimits>

Get the MR chart control limits, or None if insufficient data.

pub fn mr_points(&self) -> &[ChartPoint]

Get the MR chart points.

Trait Implementations

impl ControlChart for IndividualMRChart

fn add_sample(&mut self, sample: &[f64])

Add a single observation. The sample slice must contain exactly one element.

fn control_limits(&self) -> Option<ControlLimits>

Get the computed control limits, or None if insufficient data.

fn is_in_control(&self) -> bool

Check if the process is in statistical control.

fn violations(&self) -> Vec<Violation>

Get all violations detected across all chart points.

fn points(&self) -> &[ChartPoint]

Get all chart points.

impl Default for IndividualMRChart

fn default() -> Self

Returns the “default value” for a type.