fir1                 package:signal                 R Documentation

_F_I_R _f_i_l_t_e_r _g_e_n_e_r_a_t_i_o_n

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

     FIR filter coefficients for a filter with the given order and
     frequency cutoff.

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

     fir1(n, w, type = c("low", "high", "stop", "pass", "DC-0", "DC-1"), window = hamming(n + 1), scale = TRUE)

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

       n: order of the filter (1 less than the length of the filter) 

       w: band edges, strictly increasing vector in the range [0, 1],
          where 1 is the Nyquist frequency. A scalar for highpass or
          lowpass filters, a vector pair for bandpass or bandstop, or a
          vector for an alternating pass/stop filter. 

    type: character specifying filter type, one of '"low"' for a
          low-pass filter, '"high"' for a high-pass filter, '"stop"'
          for a stop-band (band-reject) filter, '"pass"' for a
          pass-band filter, '"DC-0"' for a bandpass as the first band
          of a multiband filter, or '"DC-1"' for a bandstop as the
          first band of a multiband filter. 

  window: smoothing window. The returned filter is the same shape as
          the smoothing window. 

   scale: whether to normalize or not. Use 'TRUE' or ''scale'' to set
          the magnitude of the center of the first passband to 1, and
          'FALSE' or ''noscale'' to not normalize.

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

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

     The FIR filter coefficients, an array of length(n+1), of class
     'Ma'.

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

     Original Octave version by Paul Kienzle, pkienzle@user.sf.net.
     Conversion to R by Tom Short.

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

     <URL: http://en.wikipedia.org/wiki/Fir_filter> 

     Octave Forge <URL: http://octave.sf.net>

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

     'filter', 'Ma', 'fftfilt', 'fir2'

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

     freqz(fir1(40,0.3))
     freqz(fir1(10,c(0.3, .5), "stop"))
     freqz(fir1(10,c(0.3, .5), "pass"))

