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Diffstat (limited to 'macros/freqz.sci')
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diff --git a/macros/freqz.sci b/macros/freqz.sci new file mode 100644 index 0000000..dc71b75 --- /dev/null +++ b/macros/freqz.sci @@ -0,0 +1,71 @@ +function [H, W] = freqz(B, varargin) +//This function returns the complex frequency response H of the rational IIR filter whose numerator and denominator coefficients are B and A, respectively. +//Calling Sequence +//[H, W] = freqz(B, A, N, "whole") +//[H, W] = freqz(B) +//[H, W] = freqz(B, A) +//[H, W] = freqz(B, A, N) +//H = freqz(B, A, W) +//[H, W] = freqz(..., FS) +//freqz(...) +//Parameters +//B, A, N: Integer or Vector +//Description +// Return the complex frequency response H of the rational IIR filter whose numerator and denominator coefficients are B and A, respectively. +// +//The response is evaluated at N angular frequencies between 0 and 2*pi. +// +//The output value W is a vector of the frequencies. +// +//If A is omitted, the denominator is assumed to be 1 (this corresponds to a simple FIR filter). +// +//If N is omitted, a value of 512 is assumed. For fastest computation, N should factor into a small number of small primes. +// +//If the fourth argument, "whole", is omitted the response is evaluated at frequencies between 0 and pi. +// +// 'freqz (B, A, W)' +// +//Evaluate the response at the specific frequencies in the vector W. The values for W are measured in radians. +// +// '[...] = freqz (..., FS)' +// +//Return frequencies in Hz instead of radians assuming a sampling rate FS. If you are evaluating the response at specific frequencies W, those frequencies should be requested in Hz rather than radians. +// +// 'freqz (...)' +// +//Plot the magnitude and phase response of H rather than returning them. +//Examples +//H = freqz([1,2,3], [4,3], [1,2,5]) +//ans = +// 0.4164716 - 0.5976772i - 0.4107690 - 0.2430335i 0.1761948 + 0.6273032i +funcprot(0); +rhs=argn(2); +lhs=argn(1); +if(rhs<2 | rhs>4) then + error("Wrong number of input arguments."); +end +if (lhs<1 | lhs>2) + error("Wrong number of output arguments."); +end +if (lhs==1) then +select(rhs) +case 1 then + H = callOctave("freqz",B); +case 2 then + H = callOctave("freqz",B, varargin(1)); +case 3 then + H = callOctave("freqz",B, varargin(1), varargin(2)); +end +elseif (lhs==2) then + select(rhs) +case 1 then + [H, W] = callOctave("freqz",B); +case 2 then + [H, W] = callOctave("freqz",B, varargin(1)); +case 3 then + [H, W] = callOctave("freqz",B, varargin(1), varargin(2)); +case 4 then + [H, W] = callOctave("freqz", B, varargin(1), varargin(2), varargin(3)); +end +end +endfunction |