在 R system.time(exp) 输出中测量的用户和系统时间是多少

发布于04月17日

我用system.time(expression)来测量R函数的执行时间.

我得到的通话输出

system.time(myfunction())

是:

    user  system elapsed   
  117.36    5.65  127.86

"用户"和"系统"衡量什么？

推荐答案

这在?proc.time中讨论(system.time()返回"proc.time"类的对象):

Details:

     ‘proc.time’ returns five elements for backwards compatibility, but
     its ‘print’ method prints a named vector of length 3.  The first
     two entries are the total user and system CPU times of the current
     R process and any child processes on which it has waited, and the
     third entry is the ‘real’ elapsed time since the process was
     started.

....和

Value:

....

     The definition of ‘user’ and ‘system’ times is from your OS.
     Typically it is something like

     _The ‘user time’ is the CPU time charged for the execution of user
     instructions of the calling process. The ‘system time’ is the CPU
     time charged for execution by the system on behalf of the calling
     process._