features                package:qualV                R Documentation

_Q_u_a_l_i_t_a_t_i_v_e _F_e_a_t_u_r_e_s _o_f _T_i_m_e _S_e_r_i_e_s

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

     A time series is characterised by a sequence of characters,
     indicating features of the time series itself, of its first or
     second derivative, steepness or level of values.

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

     f.slope(x, y, f = 0.1)
     f.curve(x, y, f = 0.1)
     f.steep(x, y, f1 = 1, f2 = 0.1)
     f.level(y, high = 0.8, low = 0.2)

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

       x: vector of time

       y: input y values

       f: factor defining the limit for constant ('f.slope') or linear
          ('f.curve') sequences

      f1: factor for the upper bound of steepness

      f2: factor for the lower bound of steepness

    high: lower limit of high values

     low: upper limit of low values

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

     For the first derivative the segment between two values is
     characterised by increasing ('A'), decreasing ('B') or constant
     ('C') and for the second by convex ('K'), concave ('I') or linear
     ('J'). For the property of the first derivative the segment
     between two values is characterised by very steep ('S'), steep
     ('T') or not steep ('U') or the values are divided into high
     ('H'), low ('L') or values in between ('M'). For the last two
     cases the values will be standardised to ignore quantitative
     deviations.

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

       v: interval sequence

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

     'LCS', 'qvalLCS'

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

     data(phyto)
     bbobs    <- dpill(obs$t, obs$y)
     n        <- tail(obs$t, n = 1) - obs$t[1] + 1
     obsdpill <- ksmooth(obs$t, obs$y, kernel = "normal", bandwidth = bbobs,
                 n.points = n)
     obss     <- data.frame(t = obsdpill$x, y = obsdpill$y)
     obss     <- obss[match(sim$t, obss$t), ]
     f.slope(obss$t, obss$y)
     f.curve(obss$t, obss$y)
     f.steep(obss$t, obss$y, f1 = 30, f2 = 10)
     f.level(obss$y)

