regconst               package:pastecs               R Documentation

_R_e_g_u_l_a_t_e _a _s_e_r_i_e_s _u_s_i_n_g _t_h_e _c_o_n_s_t_a_n_t _v_a_l_u_e _m_e_t_h_o_d

_D_e_s_c_r_i_p_t_i_o_n:

     Transform an irregular time series in a regular time series, or
     fill gaps in regular time series using the constant value method

_U_s_a_g_e:

     regconst(x, y=NULL, xmin=min(x), n=length(x),
             deltat=(max(x) - min(x))/(n - 1), rule=1, f=0)

_A_r_g_u_m_e_n_t_s:

       x: a vector with time in the irregular series. Missing values
          are allowed 

       y: a vector of same length as 'x' and holding observations at
          corresponding times 

    xmin: allows to respecify the origin of time in the calculated
          regular time series. By default, the origin is not redefined
          and it is equivalent to the smallest value in 'x' 

       n: the number of observations in the regular time series. By
          default, it is the same number than in the original irregular
          time series (i.e., 'length(x)' 

  deltat: the time interval between two observations in the regulated
          time series 

    rule: the rule to use for extrapolated values (outside of the range
          in the initial irregular time series) in the regular time
          series. With 'rule=1' (by default), these entries are not
          calculated and get 'NA'; with 'rule=2', these entries are
          extrapolated 

       f: coefficient giving more weight to the left value ('f=0', by
          default), to the right value ('f=') or to a combination of
          these two observations (0 < f <1) 

_D_e_t_a_i_l_s:

     This is the simplest, but the less powerful regulation method.
     Interpolated values are calculated according to existing
     observations at left and at right as: x[reg] = x[right]*f +
     x[left]*(f-1), with 0 < f < 1.

_V_a_l_u_e:

     An object of type 'regul' is returned. It has methods 'print()',
     'summary()', 'plot()', 'lines()', 'identify()', 'hist()',
     'extract()' and 'specs()'.

_N_o_t_e:

     This function uses 'approx()' for internal calculations

_A_u_t_h_o_r(_s):

     Frdric Ibanez (ibanez@obs-vlfr.fr), Philippe Grosjean
     (phgrosjean@sciviews.org)

_S_e_e _A_l_s_o:

     'regul', 'regarea', 'reglin', 'regspline', 'regul.screen',
     'regul.adj', 'tseries', 'is.tseries', 'approxfun'

_E_x_a_m_p_l_e_s:

     data(releve)
     reg <- regconst(releve$Day, releve$Melosul)
     plot(releve$Day, releve$Melosul, type="l")
     lines(reg$x, reg$y, col=2)

