seq.POSIXt               package:base               R Documentation

_G_e_n_e_r_a_t_e _R_e_g_u_l_a_r _S_e_q_u_e_n_c_e_s _o_f _D_a_t_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     The method for `seq' for data-time classes.

_U_s_a_g_e:

     seq(from, to, by, length.out=NULL, along.with=NULL, ...)

_A_r_g_u_m_e_n_t_s:

    from: starting date. Required

      to: end date. Optional. If supplied must be after `from'.

      by: increment of the sequence. Optional. See Details.

length.out: integer, optional. desired length of the sequence.

along.with: take the length from the length of this argument.

     ...: arguments passed to or from other methods.

_D_e_t_a_i_l_s:

     `by' can be specified in several ways.

        *  A number, taken to be in seconds.

        *  A object of class `difftime'

        *  A character string, containing one of `"sec"', `"min"',
           `"hour"', `"day"', `"DSTday"', `"week"', `"month"' or
           `"year"'.  This can optionally be preceded by an integer and
           a space, or followed by `"s"'.

     The difference between `"day"' and `"DSTday"' is that the former
     ignores changes to/from daylight savings time and the latter takes
     the same clock time each day.  (`"week"' ignores DST, but `"7
     DSTdays"') can be used as an alternative.  `"month"' and `"year"'
     allow for DST as from R 1.5.0.)

_V_a_l_u_e:

     A vector of class `"POSIXct"'.

_S_e_e _A_l_s_o:

     `DateTimeClasses'

_E_x_a_m_p_l_e_s:

     ## first days of years
     seq(ISOdate(1910,1,1), ISOdate(1999,1,1), "years")
     ## by month
     seq(ISOdate(2000,1,1), by="month", length=12)
     ## quarters
     seq(ISOdate(1990,1,1), ISOdate(2000,1,1), by="3 months")
     ## days vs DSTdays
     seq(ISOdate(2000,3,20), by="day", length = 10)
     seq(ISOdate(2000,3,20), by="DSTday", length = 10)
     seq(ISOdate(2000,3,20), by="7 DSTdays", length = 4)

