diff options
Diffstat (limited to 'macros/freqz.sci')
| -rw-r--r-- | macros/freqz.sci | 42 |
1 files changed, 14 insertions, 28 deletions
diff --git a/macros/freqz.sci b/macros/freqz.sci index 4579da3..dcd3de7 100644 --- a/macros/freqz.sci +++ b/macros/freqz.sci @@ -10,6 +10,20 @@ // Organization: FOSSEE, IIT Bombay // Email: toolbox@scilab.in +function [h_r, f_r] = freqz (b, a, n, region, Fs) +// 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. // Example usage of freqz in different formats: // [h, w] = freqz (b, a, n, "whole") // [h, w] = freqz (b) @@ -18,36 +32,8 @@ // h = freqz (b, a, w) // [h, w] = freqz (…, Fs) // freqz (...) - -/* -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. -*/ // Dependencies // fft1 unwrap2 postpad -function [h_r, f_r] = freqz (b, a, n, region, Fs) if (nargin < 1) error("Invalid numbers of inputs"); |