ezfftf, ezfftb

Functions for computing Fourier coefficients of a real periodic sequence (Fourier analysis) and vice versa.

Synopsis

    function ezfftf(
        x[*] : float
    )

    function ezfftb(
        cf[2][*]   : float,
        xbar[1] : float
    )

Arguments

x: periodic sequence to be transformed (1D array of length npts where npts need not be a power of 2)
cf: fourier coefficients (2D array dimensioned 2 x (npts/2)+1)
xbar: constant fourier coefficient

Description

Given periodic sequence x, ezfftf computes its Fourier coefficients and returns it as a 2D float array dimensioned 2 x (npts/2)+1. It also returns the constant Fourier coefficient xbar as an attribute of cf.

Given Fourier coefficients cf and constant Fourier coefficient xbar, ezfftb computes the periodic sequences and returns a 1D float array of length npts.

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$Revision: 1.5 $ $Date: 1998/11/11 23:32:17 $