iff.m

Interactive Fourier filter written as a single self-contained Matlab function.

Description

function iff(x,y)
Interactive Fourier Filter function for data in arguments x,y, with sliders for interactive control of the center frequency, width, and shape of the filter. There are four operating modes: mode=0 for band-pass filter, linear plot;
mode=1 for band-pass filter, semilogx plot;
mode=2 for band-reject (notch) filter, linear plot;
mode=3 for band-reject (notch) filter, semilogx plot.
Shape determines the sharpness of the cut-off. If shape =1, the filter is Gaussian; as shape increases the filter shape becomes more and more rectangular.

Declares global variables IFFDATA and IFFPARAMETERS. Filtered signal is returned in the global variable IFFDATA(3,:,:), so declare IFFDATA as global before calling iff.m to have access to IFFDATA outside of iff.m

T. C. O'Haver ([e-mail]), version 3, June 2008. Slider function by matthew jones ([e-mail]), 2004

• MATLAB release: MATLAB 6.5 (R13)

[Ian Howat]

??? Index exceeds matrix dimensions.

Error in ==> iff>RedrawFourierFilter at 152
if length(fy)>length(ffilter), ffilter=[ffilter ffilter(1)];end

Error in ==> iff>iffwidth at 103
ry=RedrawFourierFilter(x,y,center,width,shape,mode);

Error in ==> iff>butdownfcn at 478
            feval(params.funhand{l},out,params.h2(l)); % evaluate
            using feval()

??? Error while evaluating figure WindowButtonDownFcn

[Ian Howat]

whoops - sorry - didnt mean to give you one a rating without giving you the chance to fix this first- here's 5 stars to help even it out.

[Andre Guy Tranquille]

 

[Igor]

To Ian H.:
x and y must be row vectors.

[Tom O'Haver]

I've uploaded a new keyboard-operated interactive Fourier filer that works in recent versions of Matlab - tested in 7.8(R2009a). See http://www.mathworks.com/matlabcentral/fileexchange/31646-ifilter-interactive-fourier-filter-function