test.data              package:cthresh              R Documentation

_T_e_s_t _f_u_n_c_t_i_o_n_s _f_o_r _w_a_v_e_l_e_t _r_e_g_r_e_s_s_i_o_n _a_n_d _t_h_r_e_s_h_o_l_d_i_n_g

_D_e_s_c_r_i_p_t_i_o_n:

     This function evaluates the "blocks", "bumps", "heavisine" and
     "doppler" test functions of Donoho & Johnstone (1994b) and the
     piecewise polynomial test function of Nason & Silverman (1994).
     The function also generates data sets consisting of the specified
     function plus uncorrelated normally distributed errors.

_U_s_a_g_e:

     test.data(type = "ppoly", n = 512, signal = 1, rsnr = 7, plotfn = FALSE)

_A_r_g_u_m_e_n_t_s:

    type: Test function to be computed. Available types are "ppoly"
          (piecewise polynomial), "blocks", "bumps", "heavi"
          (heavisine), and "doppler".

       n: Number of equally spaced data points on which the function is
          evaluated. 

  signal: Scaling parameter; the function will be scaled so that the
          standard deviation of the data points takes this value.

    rsnr: Root signal-to-noise ratio. Specifies the ratio of the
          standard deviation of the function to the standard deviation
          of the simulated errors.

  plotfn: If 'plotfn=TRUE', then the test function and the simulated
          data set are plotted

_V_a_l_u_e:

     A list with the following components:  

       x: The points at which the test function is evaluated.

       y: The values taken by the test function.

  ynoise: The simulated data set.

    type: The type of function generated, identical to the input
          parameter type.

    rsnr: The root signal-to-noise ratio of the simulated data set,
          identical to the input parameter rsnr.

_S_I_D_E _E_F_F_E_C_T_S:

     If 'plotfn=T', the test function and data set are plotted.

_R_E_L_E_A_S_E:

     Part of the CThresh addon to WaveThresh. Copyright Stuart Barber
     and Guy Nason 2004.

