rmget               package:wavethresh               R Documentation

_S_e_a_r_c_h _f_o_r _e_x_i_s_t_i_n_g _i_p_n_d_a_c_w _m_a_t_r_i_c_e_s.

_D_e_s_c_r_i_p_t_i_o_n:

     Returns the integer corresponding to the smallest order 'ipndacw'
     matrix of greater than or equal to order than the order, J
     requested. 

     Not really intended for user use.

_U_s_a_g_e:

     rmget(requestJ, filter.number, family)

_A_r_g_u_m_e_n_t_s:

requestJ: A positive integer representing the order of the 'ipndacw'
          matrix that is _required_.

filter.number: The index number of the wavelet used to build the
          'ipndacw' matrix that is required.

  family: The wavelet family used to build the 'ipndacw' matrix that is
          required.

_D_e_t_a_i_l_s:

     Some of the matrices computed by 'ipndacw' take a long time to
     compute. Hence it is a good idea to store them and reuse them. 

     This function is asked to find an 'ipndacw' matrix of a particular
     order, _filter.number_ and _family_. The function steps through
     all of the directories in the 'search()' list collecting names of
     all 'ipndacw' matrices having the same _filter.number_ and
     _family_ characteristics. It then keeps any names where the
     _order_ is larger than, or equal to, the requested order. This
     means that a suitable 'ipndacw' matrix of the same or larger order
     is visible in one of the 'search()' directories. The matrix name
     with the smallest 'order' is selected and the _order_ of the
     matrix is returned. The routine that called this function can then
     'get()' the matrix and either use it "as is" or extract the
     top-left hand corner of it if 'requestJ' is less than the order
     returned by this function. 

     If no such matrix, as described by the previous paragraph, exists
     then this function returns 'NULL'. 

     This function calls the subsidiary routine 'firstdot'.

_V_a_l_u_e:

     If a matrix of order larger than or equal to the requested order
     exists somewhere on the search path _and_ the 'filter.number' and
     'family' is as specified then its order is returned. If more than
     one such matrix exists then the order of the smallest one larger
     than or equal to the requested one is returned.

     If no such matrix exists the function returns NULL.

_R_E_L_E_A_S_E:

     Version 3.9 Copyright Guy Nason 1998

_R_e_f_e_r_e_n_c_e_s:

     Nason, G.P., von Sachs, R. and Kroisandt, G. (1998). Wavelet
     processes and adaptive estimation of the evolutionary wavelet
     spectrum. _Technical Report_, Department of Mathematics University
     of Bristol/ Fachbereich Mathematik, Kaiserslautern.

_S_e_e _A_l_s_o:

     'firstdot', 'ipndacw', 'rmname'.

_E_x_a_m_p_l_e_s:

     #
     # Suppose there are no matrices in the search path.
     #
     # Let's look for the matrix rm.4.1.DaubExPhase (Haar wavelet matrix of
     # order 4)
     #
     #rmget(requestJ=4, filter.number=1, family="DaubExPhase")
     #NULL
     #
     # I.e. a NULL return code. So there were no suitable matrices.
     #
     # If we create two Haar ipndacw matrix of order 7 and 8
     #
     #ipndacw(-7, filter.number=1, family="DaubExPhase")
     #ipndacw(-8, filter.number=1, family="DaubExPhase")
     #
     # Now let's repeat the earlier search
     #
     #rmget(requestJ=4, filter.number=1, family="DaubExPhase")
     #[1] 7
     #
     # So, as we the smallest Haar ipndacw matrix available larger than
     # the requested order of 4 is "7".
     #

