MCordingley\LinearAlgebra\Matrix::recursiveSolveInverse PHP Method

    private function recursiveSolveInverse(self $source) : self
    {
        $size = $source->getRowCount();
        if ($size === 1) {
            return new static([[1 / $source->get(0, 0)]]);
        }
        $half = (int) ($size / 2);
        // Partition source matrix.
        $B = $source->sliceRows(0, $half)->sliceColumns(0, $half);
        $CT = $source->sliceRows(0, $half)->sliceColumns($half);
        $D = $source->sliceRows($half)->sliceColumns($half);
        $C = $source->sliceRows($half)->sliceColumns(0, $half);
        // Handle intermediate calculations.
        $Binv = $this->recursiveSolveInverse($B);
        $W = $C->multiplyMatrix($Binv);
        $WT = $W->transpose();
        $X = $W->multiplyMatrix($CT);
        $S = $D->subtractMatrix($X);
        $Sinv = $this->recursiveSolveInverse($S);
        $V = $Sinv;
        $Y = $Sinv->multiplyMatrix($W);
        $YT = $Y->transpose();
        $T = $YT->multiplyScalar(-1);
        $U = $Y->multiplyScalar(-1);
        $Z = $WT->multiplyMatrix($Y);
        $R = $Binv->addMatrix($Z);
        // Stitch together intermediate results into the final result
        return $R->concatenateRight($T)->concatenateBottom($U->concatenateRight($V));
    }