Sommario
What is FFT y = FFT (X)?
Y = fft(X) computes the discrete Fourier transform (DFT) of X using a fast Fourier transform (FFT) algorithm. If X is a vector, then fft(X) returns the Fourier transform of the vector. If X is a matrix, then fft(X) treats the columns of X as vectors and returns the Fourier transform of each column.
What is transform length in FFT?
Transform length, specified as [] or a nonnegative integer scalar. Specifying a positive integer scalar for the transform length can increase the performance of fft. The length is typically specified as a power of 2 or a value that can be factored into a product of small prime numbers.
How does MATLAB coder™ generate code for FFT algorithms?
For MEX output, MATLAB ® Coder™ uses the library that MATLAB uses for FFT algorithms. For standalone C/C++ code, by default, the code generator produces code for FFT algorithms instead of producing FFT library calls. To generate calls to a specific installed FFTW library, provide an FFT library callback class.
How to get the Fourier transform of a vector in MATLAB?
If X is a vector, then fft (X) returns the Fourier transform of the vector. If X is a matrix, then fft (X) treats the columns of X as vectors and returns the Fourier transform of each column.
When n is specified in FFT?
When n is specified, fft (X,n,dim) pads or truncates X to length n along dimension dim. Frequency domain representation returned as a vector, matrix, or multidimensional array. If X is of type single , then fft natively computes in single precision, and Y is also of type single . Otherwise, Y is returned as type double.
How to use Fourier transform in FFT with example?
For example, if X is a matrix, then fft (X,n,2) returns the n-point Fourier transform of each row. Use Fourier transforms to find the frequency components of a signal buried in noise. Specify the parameters of a signal with a sampling frequency of 1 kHz and a signal duration of 1.5 seconds.