
1-Dimensional Data Sets 105
ψ
i
and Y
k
because the Y
k
can grow with n, a number that can be arbitrarily
large. Keep in mind that the units of the Y
k
are different than the units of
the continuous Fourier transform, w hich are those of the continuous function
ψ multiplied by a factor of the units of the independent variable.
The far right-hand s ide of Equation 5.24 explicitly connects a Y
k
compo-
nent and a wave that completes k oscillations over the length of the data set.
Euler’s formula, given by e
iωτ
= cos ωτ + i sin ωτ , makes clear the connection
between the exponent and sinusoidal waves with angula r frequency ω. The
k = 0 component, as you would exp ...