stf-methods             package:FLAssess             R Documentation

_P_r_o_j_e_c_t_i_o_n _p_r_e_p_a_r_a_t_i_o_n _f_o_r _F_L_R

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

     Extends an FLStock object along the year dimensin and prepares
     some of the slots for forward stock projection, using a similar
     method to FLSTF.  Can be used in conjunction with fwd() for
     validating assessments.

_G_e_n_e_r_i_c _F_u_n_c_t_i_o_n:


     _U_s_a_g_e 
          stf(object,nyears=3,wts.nyears=3,fbar.nyears=NA,arith.mn=TRUE,
          na.rm=TRUE)

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

            'object': 'FLStock' object the forecast is to be perfomed
               on.

            'nyears': Number of years to extend the stock object by,
               i.e. number of forecast years.

            'wts.nyrs': Number of years over which to calculate mean
               for *.wt, *.spwn, mat and m slots.

            'fbar.nyrs': Number of years over which to calculate mean
               for harvest slot.

          _d_i_s_c._n_y_r_s Number of years over which to calculate mean for
               discards.n and landings.n slots, If unspecified,
               wts.nyrs is used.

          _a_r_i_t_h._m_n Boolean - if TRUE use arithmetic mean, if FALSE use
               geometric mean.

            'na.rm': Boolean - whether to ignore NA values when
               calculating means.

     _V_a_l_u_e 'FLStock' object

_M_e_t_h_o_d_s:


     _o_b_j_e_c_t="_F_L_S_t_o_c_k" : Extends the stock object by a number of years
          and estimates the values in the future years of the slots.

          The future values of the mat, m, harvest.spwn, m.spwn,
          harvest and all *.wt slots are set to the mean (geometric or
          arithmetic) value of the last user defined number of years.

          The future values of the discards.n and landings.n slots are
          returned only as estimated proportions, not actual numbers. 
          The proportions are calculated as the mean proportion of the
          sum of the landings and discard numbers over wts.years.

          The remaining slots (stock.n, catch.n, stock, catch,
          discards, landings) are set to NA.

          Not yet implemented for multiple seasons or areas.

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

     FLR Team

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

     'FLAssess-class', 'FLStock-class'

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

     # load ple4
     data(ple4)
     # stf with default settings
     ple4.stf <- stf(ple4, nyears=3, wts.nyears=4, fbar.nyears=3)

