绘制二维密度散点图，根据x，y的最大最小值将坐标分成若干小格，然后统计落在每个小格里的点数，最后形成的就是一个矩阵，然后直接出图-Drawing two-dimensional density scatter plot, according to the x, y minimum and maximum values ​ ​ of the coordinates into a number of small cells, then every little statistic

热力散点图，包含三个参数，横纵坐标和热力棒，能将三个参数详细显示在二维坐标图中。-Thermal scatter plot, including three parameters, horizontal ordinate and thermal rods, three parameters can be shown in detail in the two-dimensional coordinate diagram.