Documentation

This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English verison of the page.

Note: This page has been translated by MathWorks. Please click here
To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.

sigwin.nuttallwin class

Package: sigwin

Construct Nuttall defined 4–term Blackman-Harris window object

Description

    Note:   The use of sigwin.nuttallwin is not recommended. Use nuttallwin instead.

sigwin.nuttallwin creates a handle to a Nuttall defined 4–term Blackman-Harris 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.

Construction

H = sigwin.nuttallwin returns a Nuttall defined 4–term Blackman-Harris window object window object H of length 64.

H = sigwin.nuttallwin(Length) returns a Nuttall defined 4–term Blackman-Harris window object H of length Length. Entering a positive noninteger value for Length rounds the length to the nearest integer. Entering a 1 for Length results in a window with a single value of 1. The SamplingFlag property defaults to 'symmetric'.

Properties

Length

Nuttall defined 4–term Blackman-Harris window length. The window length must be a positive integer. Entering a positive noninteger value for Length rounds the length to the nearest integer. Entering a 1 for Length results in a window with a single value of 1.

SamplingFlag

The type of window returned as one of 'symmetric' or 'periodic'. The default is 'symmetric'. A symmetric window exhibits perfect symmetry between halves of the window. Setting the SamplingFlag property to 'periodic' results in a N-periodic window. The equations for the Nuttall defined 4–term Blackman-Harris window differ slightly based on the value of the SamplingFlag property. See Definitions for details.

Methods

generateGenerates Nuttall defined 4–term Blackman-Harris window
infoDisplay information about Nuttall defined 4–term Blackman-Harris window object
winwriteSave Nuttall defined 4-term Blackman-Harris window object values in ASCII file

Definitions

The following equation defines the symmetric Nuttall defined 4–term Blackman-Harris window of length N.

w(n)=a0a1cos(2πnN1)+a2cos(4πnN1)a3cos(6πnN1),0nN1

The following equation defines the periodic Nuttall defined 4–term Blackman-Harris window of length N.

w(n)=a0a1cos2πnN+a2cos4πnNa3cos6πnN,0nN1

The following table lists the coefficients:

CoefficientValue
a00.3635819
a10.4891775
a20.1365995
a30.0106411

Copy Semantics

Handle. To learn how copy semantics affect your use of the class, see Copying Objects in the MATLAB® Programming Fundamentals documentation.

Examples

Construct a length N = 64 symmetric Nuttall defined 4–term Blackman-Harris window:

H = sigwin.nuttallwin;
wvtool(H)

Generate a length N = 128 periodic Nuttall defined 4-term Blackman-Harris window, return values, and write ASCII file:

H = sigwin.nuttallwin(128);
H.SamplingFlag = 'periodic';
% Return window with generate
win = generate(H);
% Write ASCII file in current directory
% with window values
winwrite(H,'nuttallwin_128')

Related Examples

References

Nuttall, A. H. "Some Windows with Very Good Sidelobe Behavior." IEEE® Transactions on Acoustics, Speech, and Signal Processing. Vol. 29, 1981, pp. 84–91.

Was this topic helpful?