Construct Hann (Hanning) window object
The use of
sigwin.hann creates a handle to a Hann window
object for use in spectral analysis and FIR filtering by the window
method. Object methods enable workspace import and ASCII file export
of the window values.
The symmetric Hann window of length
where M is N/2 for N even and (N + 1)/2 for N odd.
The second half of the symmetric Hann window is obtained by flipping the first half around the midpoint. The symmetric option is the preferred method when using a Hann window in FIR filter design.
The periodic Hann window is constructed by extending the desired window length by one sample, constructing a symmetric window, and removing the last sample. The periodic version is the preferred method when using a Hann window in spectral analysis because the discrete Fourier transform assumes periodic extension of the input vector.
H = sigwin.hann returns a symmetric Hann
H of length 64.
H = sigwin.hann( returns
a symmetric Hann window object with length
a positive integer. Entering a positive noninteger value for
the length to the nearest integer. Entering a 1 for
in a window with a single value of 1.
H = sigwin.hann( returns
a Hann window object with sampling
SamplingFlag can be either
Hann window length. Must be a positive integer. Entering a positive
noninteger value for
|generate||Generates Hann window|
|info||Display information about Hann window object|
|winwrite||Save Hann window object values in ASCII file|
Handle. To learn how copy semantics affect your use of the class, see Copying Objects (MATLAB) in the MATLAB® Programming Fundamentals documentation.
Generate two Hann windows:
The first window has N = 64 and is symmetric.
The second window has N = 63 and is periodic.
Display the two windows.
Hs = sigwin.hann(64,'symmetric'); Hp = sigwin.hann(63,'periodic')
Hp = Name: 'Hann' SamplingFlag: 'periodic' Length: 63
wvt = wvtool(Hs,Hp); legend(wvt.CurrentAxes,'Symmetric','Periodic')
Generate a symmetric Hann window with N = 16. Return the window values as a column vector. Write the coefficients to an ASCII file in the current directory. Show information about the window object. Display the window.
H = sigwin.hann(16); win = generate(H)
win = 0 0.0432 0.1654 0.3455 0.5523 0.7500 0.9045 0.9891 0.9891 0.9045
winwrite(H,'hann_16'); wininfo = info(H)
wininfo = 4×26 char array 'Hann Window ' '----------- ' 'Length : 16 ' 'Sampling Flag : symmetric'
Oppenheim, Alan V., and Ronald W. Schafer. Discrete-Time Signal Processing. Upper Saddle River, NJ: Prentice Hall, 1989.