diff options
Diffstat (limited to 'macros/fir2.sci')
| -rw-r--r-- | macros/fir2.sci | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/macros/fir2.sci b/macros/fir2.sci index 418a9e4..990fb3e 100644 --- a/macros/fir2.sci +++ b/macros/fir2.sci @@ -1,7 +1,29 @@ function B = fir2(N, F, M, varargin) - +//Produce an order N FIR filter with arbitrary frequency response M over frequency bands F, returning the N+1 filter coefficients in B. +//Calling Sequence +//B = fir2(N, F, M) +//B = fir2(N, F, M, GRID_N) +//B = fir1(N, F, M, GRID_N, RAMP_N) +//B = fir1(N, F, M, GRID_N, RAMP_N, WINDOW) +//Parameters +//N: Integer +//F, M: Vector +//Description +//Produce an order N FIR filter with arbitrary frequency response M over frequency bands F, returning the N+1 filter coefficients in B. The vector F specifies the frequency band edges of the filter response and M specifies the magnitude response at each frequency. +// +//The vector F must be nondecreasing over the range [0,1], and the first and last elements must be 0 and 1, respectively. A discontinuous jump in the frequency response can be specified by duplicating a band edge in F with different values in M. +// +//The resolution over which the frequency response is evaluated can be controlled with the GRID_N argument. The default is 512 or the next larger power of 2 greater than the filter length. +// +//The band transition width for discontinuities can be controlled with the RAMP_N argument. The default is GRID_N/25. Larger values will result in wider band transitions but better stopband rejection. +// +//An optional shaping WINDOW can be given as a vector with length N+1. If not specified, a Hamming window of length N+1 is used. +//Examples +// fir2 (10, [0, 0.5, 1], [1, 2, 3]) +//ans = +// -0.00130 0.00000 -0.01792 0.00000 -0.36968 2.00000 -0.36968 0.00000 -0.01792 0.00000 -0.00130 funcprot(0); -rhs = argn(2) +rhs = argn(2); if(rhs<3 | rhs>6) error("Wrong number of input arguments."); end @@ -9,11 +31,11 @@ end select(rhs) case 3 then B = callOctave("fir2", N, F, M); - case 4 then - B = callOctave("fir2", N, F, M, varargin(1)); - case 5 then - B = callOctave("fir2", N, F, M, varargin(1), varargin(2)); - case 6 then - B = callOctave("fir2", N, F, M, varargin(1), varargin(2), varargin(3)); + case 4 then + B = callOctave("fir2", N, F, M, varargin(1)); + case 5 then + B = callOctave("fir2", N, F, M, varargin(1), varargin(2)); + case 6 then + B = callOctave("fir2", N, F, M, varargin(1), varargin(2), varargin(3)); end endfunction |