README

phit is a PHP extension, written in Rust, for regression and mixed models, probability distributions, and descriptive statistics. Models are written as R formulas over named columns. A fit prints its summary in R's layout and reads like a PHP array.

Documentation · Installation · A first model · API overview · Verification

use Phibble\DataFrame;

use function Phit\{fit_ols, predict};

$cars = DataFrame::fromCsv(
    'https://raw.githubusercontent.com/phpstats/datasets/main/csv/mtcars.csv',
);

$fit = fit_ols('mpg ~ wt + factor(cyl)', $cars);
echo $fit;

$p = predict(
    $fit,
    ['wt' => [2.5], 'cyl' => [4]],
    interval: 'prediction',
);
// $p['fit'], $p['lower'], and $p['upper'] are lists, one value per row.

Linear model fit by least squares
Formula: mpg ~ wt + factor(cyl)

Coefficients:
             Estimate Std. Error t value Pr(>|t|)
(Intercept)   33.9908     1.8878  18.006  < 2e-16
wt            -3.2056     0.7539  -4.252 0.000213
factor(cyl)6  -4.2556     1.3861  -3.070 0.004718
factor(cyl)8  -6.0709     1.6523  -3.674 0.000999

Residual standard error: 2.557 on 28 degrees of freedom
Multiple R-squared: 0.8374, Adjusted R-squared: 0.82
F-statistic: 48.08 on 3 and 28 DF, p-value: 3.594e-11

The example reads mtcars with phibble (composer require phpstats/phibble).

Installation

pie install phpstats/phit

phit supports PHP 8.3, 8.4, and 8.5, non-thread-safe builds, on Linux and macOS. On Linux x86_64 and arm64 with glibc 2.35 or later, PIE downloads a prebuilt binary from the release. Elsewhere, including macOS, it builds from source, which needs Rust, Clang, libclang, and PHP's development files. The installation guide covers both and how to check the install.

phit-polyfill (composer require phpstats/phit-polyfill) provides the same functions in plain PHP, except the CSV reader (read_csv and CsvReader), for hosts where extensions cannot be installed.

Features

All functions are in the Phit namespace. stubs/phit.php declares them for IDEs and static analysis; do not load it at runtime.

Development

Building from a checkout, running the tests, and the release process are described in the development guide. The complete check is:

PHP_CONFIG=/path/to/php-config ./scripts/check

License

MIT. Bundled reference datasets and third-party code keep their original licenses; see licensing. THIRD_PARTY_NOTICES.md lists the third-party software and its licenses.