Draws the Kaplan-Meier plot and calculates the log-rank test (log rank test is only for two group).
It is okay to leave empty cells, empty cells or non numeric cells won't be counted
|k||number of groups|
|χ²||Chi square test statistic|
Event: Maintenance failure, recovery, disease occurrence, death, etc.
Censored event: the main event didn't happen since the subject left the experiment before the ending time, or due to the termination of the experiment.
The following R code should produce the same results as the alternative log-rank test