freqs                 package:signal                 R Documentation

_s-_p_l_a_n_e _f_r_e_q_u_e_n_c_y _r_e_s_p_o_n_s_e

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

     Compute the s-plane frequency response of an ARMA model (IIR
     filter).

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

     ## Default S3 method:
     freqs(filt = 1, a = 1, W, ...)

     ## S3 method for class 'Arma':
     freqs(filt, ...)

     ## S3 method for class 'Ma':
     freqs(filt, ...)

     ## S3 method for class 'freqs':
     print(x, ...)

     ## S3 method for class 'freqs':
     plot(x, ...)

     ## Default S3 method:
     freqs_plot(w, h, ...) 

     ## S3 method for class 'freqs':
     freqs_plot(w, ...) 

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

    filt: for the default case, the moving-average coefficients of an
          ARMA model or filter. Generically, 'filt' specifies an
          arbitrary model or filter operation.

       a: the autoregressive (recursive) coefficients of an ARMA
          filter. 

       W: the frequencies at which to evaluate the model. 

       w: for the default case, the array of frequencies. Generically,
          'w' specifies an object from which to plot a frequency
          response. 

       h: a complex array of frequency responses at the given
          frequencies. 

       x: object to be plotted. 

     ...: additional arguments passed through to 'plot'. 

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

     When results of 'freqs' are printed, 'freqs_plot' will be called
     to display frequency plots of magnitude and phase. As with
     'lattice' plots, automatic printing does not work inside loops and
     function calls, so explicit calls to 'print' are needed there.

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

     For 'freqs' list of class 'freqs' with items: 

      H : array of frequencies. 

      W : complex array of frequency responses at those frequencies.

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

     Original Octave version by Julius O. Smith III. Conversion to R by
     Tom Short.

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

     'filter', 'Arma', 'freqz'

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

     b = c(1, 2)
     a = c(1, 1)
     w = linspace(0, 4, 128)
     freqs(b, a, w)

