simple_statistics

Overview

simple_statistics is a production-ready statistical analysis library for Eiffel. It provides type-safe, verified implementations of descriptive statistics, correlation analysis, linear regression, and hypothesis testing.

Every feature is specified with Design by Contract (require/ensure/invariant) and verified through 43 comprehensive tests including adversarial and stress testing.

Part of the Simple Eiffel ecosystem.

Features

• Descriptive Statistics: mean, median, variance, standard deviation, percentiles, quartiles, mode
• Correlation & Covariance: Pearson correlation coefficient and covariance analysis
• Linear Regression: Ordinary least squares with R² and prediction capability
• Hypothesis Testing: t-tests (one-sample, two-sample, paired), chi-square, ANOVA
• Numerical Stability: Welford's algorithm, Kahan summation, careful computation
• Design by Contract: Full contract specification with verified postconditions
• Data Cleaning: Utilities to remove NaN and infinite values

Status

v1.0.0 - Production Ready

Quick Start

See Quick API Reference for immediate examples.

Basic Example

create stats.make
data := {ARRAY [REAL_64]} << 1.0, 2.0, 3.0, 4.0, 5.0 >>

-- Compute statistics
avg := stats.mean (data)
std := stats.std_dev (data)
med := stats.median (data)

For comprehensive documentation, start with the User Guide.

Installation

Add to your ECF configuration file:

<library name="simple_statistics" location="$SIMPLE_EIFFEL/simple_statistics/simple_statistics.ecf"/>

Then create and use in your Eiffel code:

create stats.make
result := stats.mean (your_data)

Documentation

• Quick API Reference - Five-minute overview
• User Guide - Comprehensive tutorial with examples
• API Reference - Complete class and feature documentation
• Architecture - Design decisions and structure
• Cookbook - Real-world usage patterns and recipes

Support & Community

• GitHub Repository: simple-eiffel/simple_statistics
• Issue Tracker: Report bugs and request features
• Simple Eiffel: Visit the main ecosystem