hist.POSIXt               package:base               R Documentation

_H_i_s_t_o_g_r_a_m _o_f _a _D_a_t_e-_T_i_m_e _O_b_j_e_c_t

_D_e_s_c_r_i_p_t_i_o_n:

     Method for `hist' applied to date-time objects.

_U_s_a_g_e:

     hist(x, breaks, ..., plot = TRUE, freq = FALSE,
          start.on.monday = TRUE, format)

_A_r_g_u_m_e_n_t_s:

       x: an object inheriting from class `"POSIXt"'.

  breaks: a vector of cut points or number giving the number of
          intervals which `x' is to be cut into or an interval
          specification, one of `"secs"', `"mins"', `"hours"',
          `"days"', `"weeks"', `"months"' or `"years"'. 

     ...: graphical parameters.

    plot: logical.  If `TRUE' (default), a histogram is plotted,
          otherwise a list of breaks and counts is returned.

    freq: logical; if `TRUE', the histogram graphic is a representation
          of frequencies, i.e, the `counts' component of the result; if
          `FALSE', relative frequencies (``probabilities'') are
          plotted.

start.on.monday: logical. If `breaks = "weeks"', should the week start
          on Mondays or Sundays?

  format: for the x-axis labels. See `strptime'.

_V_a_l_u_e:

     An object of class `"histogram"': see `hist'.

_S_e_e _A_l_s_o:

     `seq.POSIXt', `axis.POSIXct', `hist'

_E_x_a_m_p_l_e_s:

     hist(.leap.seconds, "years", freq = TRUE)
     hist(.leap.seconds,
          seq(ISOdate(1970, 1, 10), ISOdate(2002, 1, 1), "5 years"))

     ## 100 random dates in a 10-week period
     random.dates <- ISOdate(2001, 1, 1) + 70*86400*runif(100)
     hist(random.dates, "weeks", format = "%d %b")

