dextract                 package:emu                 R Documentation

_E_x_t_r_a_c_t _a _s_u_b_s_e_t _o_f _d_a_t_a _f_r_o_m _a _t_r_a_c_k_d_a_t_a _o_b_j_e_c_t

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

     A function that cuts up trackdata either at a proportional time or
     proportionally between two times. It is a subsidiary function of
     dplot()

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

     dextract(dataset, start, end)

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

 dataset: A trackdata object

   start: A single valued numeric vector corresponding to a
          proportional time between zero (the onset of the trackdata)
          and one (the offset of the trackdata).

     end: As start, but optional

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

     If both start and end are specified, a trackdata object is
     returned, otherwise a vector if the original trackdata is
     one-dimensional and the end argument is not used, or a matrix if
     the original trackdata has more than one dimension and the end
     argument is not used

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

     Jonathan Harrington

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

     'dcut'

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

     data(demo.vowels.f0)
     data(demo.vowels.fm)

     form = demo.vowels.fm
     # get the formants at the midpoint: f50 is a matrix
     # same as dcut(form, .5, prop=TRUE)
     f50 = dextract(form, 0.5)
     # get the formants between the 25
     # fcut is a trackdata object
     # same as dcut(form, .25, .75, prop=TRUE)
     fcut = dextract(form, 0.25, 0.75)
     # get  F0 at the midpoint. fzero50 is a vector
     # same as dcut(fzero, .5, prop=TRUE)
     fzero = demo.vowels.f0
     fzero50 = dextract(fzero, 0.5)

