目前已有若干版本的子程序库公开发表，它们各有特色。本程序库中的开平方算法为快速逼近算法，它能达到牛顿迭代法同样的精度，而速度加快二十倍左右，超过双字节定点除法的速度。 -there are several versions of the subroutine library published their own characteristics. The library opened in the square approximation algorithm for rapid algorith

Since objects stored in a spatial can be rather complex they are often approximated by simpler objects, and spatial indexes are then built on these approximations. The most commonly used approximation is the minimal bounding box: the smallest