seq.Date                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 objects of class class '"Date"'
     representing calendar dates.

_U_s_a_g_e:

     ## S3 method for class 'Date':
     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.

      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 days.

        *  A object of class 'difftime'

        *  A character string, containing one of '"day"', '"week"',
           '"month"' or '"year"'.  This can optionally be preceded by a
           (positive or negative) integer and a space, or followed by
           '"s"'.

           See 'seq.POSIXt' for the details of '"month"'.

_V_a_l_u_e:

     A vector of class '"Date"'.

_S_e_e _A_l_s_o:

     'Date'

_E_x_a_m_p_l_e_s:

     ## first days of years
     seq(as.Date("1910/1/1"), as.Date("1999/1/1"), "years")
     ## by month
     seq(as.Date("2000/1/1"), by="month", length.out=12)
     ## quarters
     seq(as.Date("2000/1/1"), as.Date("2003/1/1"), by="3 months")

     ## find all 7th of the month between two dates, the last being a 7th.
     st <- as.Date("1998-12-17")
     en <- as.Date("2000-1-7")
     ll <- seq(en, st, by="-1 month")
     rev(ll[ll > st & ll < en])