proc.time                package:base                R Documentation

_R_u_n_n_i_n_g _T_i_m_e _o_f _R

_D_e_s_c_r_i_p_t_i_o_n:

     'proc.time' determines how much time (in seconds) the currently
     running R process already consumed.

_U_s_a_g_e:

     proc.time()

_V_a_l_u_e:

     A numeric vector of length 5, containing the user, system, and
     total elapsed times for the currently running R process, and the
     cumulative sum of user and system times of any child processes
     spawned by it.

     The resolution of the times will be system-specific; and times are
     rounded to the nearest 1ms.  On modern systems they will be that
     accurate, but on older systems they might be accurate to 1/100 or
     1/60 sec.

     It is most useful for "timing" the evaluation of R expressions,
     which can be done conveniently with 'system.time'.

_N_o_t_e:

     It is possible to compile R without support for 'proc.time', when
     the function will throw an error.

_R_e_f_e_r_e_n_c_e_s:

     Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) _The New S
     Language_. Wadsworth & Brooks/Cole.

_S_e_e _A_l_s_o:

     'system.time' for timing a valid R expression, 'gc.time' for how
     much of the time was spent in garbage collection.

_E_x_a_m_p_l_e_s:

     ## Not run: 
     ## a way to time an R expression: system.time is preferred
     ptm <- proc.time()
     for (i in 1:50) mad(runif(500))
     proc.time() - ptm
     ## End(Not run)

