中文说明：用于模式识别中的PCA降维输入数据data和option。data是一个矩阵，每一行代表一个样本。option是选择降维到多少维。
English Description：
It is used for PCA dimension reduction input data data and option in pattern recognition. Data is a matrix, and each row represents a sample. Option is to select how many dimensions to reduce.