求翻译：为了确定一片叶子的叶脉形状，我们定义了以下三个变量，叶脉长度Li，叶脉广度Wi以及叶肉面积Si，叶脉长度Li是主叶脉的长度，叶脉广度Wi是指叶子的宽度，叶肉面积Si是指单片叶子的面积。通过前期的准备以及分析，我们发现年降水量、年蒸发量、年光照、土壤有机质百分比四个指标对叶脉的形状是有影响。我们设叶脉长度与年降水量、年蒸发量、年光照及土壤有机质百分比之间的函数关系为：是什么意思？

In order to determine the shape of a leaf veins, we define the following three variables, the vein length li, the veins breadth wi and mesophyll area si vein length li is the length of the main veins vein breadth wi, refers to the width of the leaf mesophyll area si refers to the area of ​​monolithi

In order to determine the leaf leaves pulse shape, we have defined the following three variables, Yip, Yip Li pulse length pulse width Wi mesophyll area as well as pulse length Li Si, China is China's main IP veins in the length, breadth Wi pulse width refers to the leaves Si mesophyll area is a sin

In order to determine the veins of a leaf shape, we have defined the following three variables, Li vein length, breadth Wi veins and leaves an area Si, Li vein length is the length of the main vein, breadth Wi vein refers to the width of the leaf, mesophyll Si area refers to the area of a single lea