比较生存曲线可以用统计假设测试日志秩检验。它是用来测试的零假设，没有任何区别的人口的生存曲线（即概率事件发生在任何时间点是相同的每个人口）.这个函数使用卡普兰曲线的程序来估计生存函数.-Comparison of two survival curves can be done using a statistical hypothesis test called the log rank test. It is used to test the null hypothesis that there is no difference between the population survival curves (i.e. the probability of an event occurring at any time point is the same for each population). This function use the Kaplan-Meier procedure to estimate the survival function, so it is mandatory to download