Fourier analysis and filtering

Current issues ：

From the state average equation to the transfer function ,syms Signed cannot participate in ss2tf Arithmetic , Because there is no real value .
So it's difficult .

Fourier analysis and filtering

[b,a] = ss2tf(A,B,C,D) The state space representation of the equations is transformed into an equivalent transfer function .ss2tf Returns the Laplace transform transfer function of continuous time equations and the transfer function of discrete time equations Z Transform transfer function .

Transforms and filters are tools for processing and analyzing discrete data , Commonly used in signal processing applications and computational mathematics . When data is expressed as a function of time or space , The Fourier transform decomposes the data into frequency components .fft The function uses the fast Fourier transform algorithm , Compared with other direct implementations , This method can reduce the calculation cost . More details about Fourier analysis , See Fourier transform . When modifying the amplitude or phase of input data using transfer function ,conv and filter Functions are also useful tools .

[b,a] = ss2tf(A,B,C,D,ni) Returns the number of equations with multiple inputs ni The transfer function generated when an input is affected by a unit pulse .

Fs = 5;               % frequency 5Hz
dt = 1/Fs;            % Sampling interval