是学习PCA特征提取的很好的学习资料，包括面积、周长、矩形度、伸长度，多元数据分析的主分量分析投影。- Is a good learning materials to learn PCA feature extraction, Including the area, perimeter, rectangular, elongation, Principal component analysis of multivariate data analysis projection.

根据经度纬度，计算卯酉圈半径、子午圈半径、纬圈半径、子午圈弧长、平行圈弧长和梯形图幅面积。