icm                  package:Rwave                  R Documentation

_R_i_d_g_e _E_s_t_i_m_a_t_i_o_n _b_y _I_C_M _M_e_t_h_o_d

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

     Estimate a (single) ridge from a time-frequency representation,
     using the ICM minimization method.

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

     icm(modulus, guess, tfspec=numeric(dim(modulus)[2]), subrate=1,
     mu=1, lambda=2 * mu, iteration=100)

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

 modulus: Time-Frequency representation (real valued). 

   guess: Initial guess for the algorithm. 

  tfspec: Estimate for the contribution of the noise to modulus. 

 subrate: Subsampling rate for ridge estimation. 

      mu: Coefficient of the ridge's second derivative in cost
          function. 

  lambda: Coefficient of the ridge's derivative in cost function. 

iteration: Maximal number of moves. 

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

     To accelerate convergence, it is useful to preprocess modulus
     before running annealing method. Such a preprocessing (smoothing
     and subsampling of modulus) is implemented in `icm'. The parameter
     subrate specifies the subsampling rate.

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

     Returns the estimated ridge and the cost function. 

   ridge: 1D array (of same length as the signal) containing the ridge. 

    cost: 1D array containing the cost function. 

_R_e_f_e_r_e_n_c_e_s:

     See discussions in the text of ``Practical Time-Frequency
     Analysis''.

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

     `corona', `coronoid', and `snake', `snakoid'.

