天顶投影

Based on the ISC earthquake catalogue data, according to the orbit equations of two-body-problem and the perturbation theory of celestial mechanics, we could determine the projection pole of the sun, and thus calculate the zenith distance from the sun to the epicenter. After calculating all the earthquakes on their zenith distances, we could get the distribution of the solar zenith distance versus the occurring probability of earthquakes.

基于ISC地震记录，利用天体动力学中二体问题的轨道方程和摄动理论，确定发震时刻太阳在地面的投影点位置，并进一步计算出太阳相对震中的地心天顶距，将地震按天顶距的大小进行统计，得到地震的太阳天顶距地震频度分布。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。