php如何用最小二乘法拟合二元一次方程 计算方程的X和Y值

如果是扩展，没有。

如果是composer包，那和自己写个func没啥区别。

function linearRegression($x, $y) {
    $n = count($x);
    $sum_x = array_sum($x);
    $sum_y = array_sum($y);
    $sum_xy = dotProduct($x, $y);
    $sum_xx = dotProduct($x, $x);

    $slope = ($sum_xy - ($sum_x * $sum_y) / $n) / ($sum_xx - ($sum_x * $sum_x) / $n);
    $intercept = $sum_y / $n - $slope * $sum_x / $n;

    return [$slope, $intercept];
}

function dotProduct($x, $y) {
    $result = 0;
    $n = count($x);
    for ($i = 0; $i < $n; $i++) {
        $result += $x[$i] * $y[$i];
    }
    return $result;
}

$x = array(20,40,60,80,100);
$y = array(3,6.5,9.1,12.1,15.3);

list($slope, $intercept) = linearRegression($x, $y);

echo "Slope: $slope\n";
echo "Intercept: $intercept\n";