covarian matrix

例句：

1. 1. The covariance matrix of the data is calculated to determine the relationships between variables.
   计算数据的协方差矩阵以确定变量之间的关系。
2. 2. In statistics, the covariance matrix is used to describe the relationship between variables.
   在统计学中，协方差矩阵用于描述变量之间的关系。
3. 3.The covariance matrix is important for understanding the structure of a dataset.
   协方差矩阵对于理解数据集的结构非常重要。