modjitter               package:adlift               R Documentation

_m_o_d_j_i_t_t_e_r

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

     This function jitters grid values by a proportion of the regular
     distance between consecutive gridpoints and then alters it to lie
     in [0,1].

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

     modjitter(x, amount)

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

       x: a vector to be jittered (e.g. a gridpoint vector). 

  amount: a value of how much to jitter the vector (expressed as a
          proportion of the regular gridpoint distance, d). 

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

     The function uses dojitter to jitter the gridpoint vector by
     ('amount*d') . The endpoints are fixed to be zero and one, and the
     corresponding 'jx' values to 'x[2]' and 'x[length(x)-1]' are
     randomised again in the intervals '[0,x[2]+amount*d]' and
     '[x[length(x)-1]-amount*d,1]' respectively.

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

      jx: the jittered version of 'x'

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

     Matt Nunes (matt.nunes@bristol.ac.uk), Marina Popa
     (Marina.Popa@bristol.ac.uk)

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

     'dojitter', 'make.signal2'

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

     #create grid vector
     #
     xgrid<-seq(0,1,length=51)
     #
     xgrid
     #
     #a regularly-spaced grid on [0,1]
     #
     modjitter(xgrid,1)
     #
     #jitters xgrid with a maximum change of .02, keeping endpoints of zero and one 

