1.strange and unconventional behavior
2.(geometry) a ratio describing the shape of a conic section; the ratio of the distance between the foci to the length of the major axis;
a circle is an ellipse with zero eccentricity
3.a circularity that has a different center or deviates from a circular path
eccentricity 离心率 椭圆(行星的公转轨道)的离心率即是指椭圆上点到焦点的距离与到准线的距离的比值。公式: 离心率=(ra-rp)/(ra+rp),ra指远日点距离,rp指近日点距离。