#### Matlab for Parabolic Peak Interpolation

Section §F.2 lists Matlab/Octave code for finding
quadratically interpolated peaks in the magnitude spectrum as
discussed above. At the heart is the `qint` function, which
contains the following:

function [p,y,a] = qint(ym1,y0,yp1) %QINT - quadratic interpolation of three adjacent samples % % [p,y,a] = qint(ym1,y0,yp1) % % returns the extremum location p, height y, and half-curvature a % of a parabolic fit through three points. % Parabola is given by y(x) = a*(x-p)^2+b, % where y(-1)=ym1, y(0)=y0, y(1)=yp1. p = (yp1 - ym1)/(2*(2*y0 - yp1 - ym1)); y = y0 - 0.25*(ym1-yp1)*p; a = 0.5*(ym1 - 2*y0 + yp1);

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Minimum Zero-Padding for High-Frequency Peaks

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Phase Interpolation at a Peak