Fourier MultiLab, Руководство пользователя

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72 Chapter 2 MultiLab Software
Derivative
rate sampling
t
t
y y
y
n n
n
1
,
2
1 1 = Δ
Δ
−
=
− +
Draws a line of the slopes of every three consecutive points of a data
set. For high recording rates and small
Δ
t, this line may be very noisy,
which is why smoothing the data set is recommended before applying
the derivative function.
Divide
2
1
BG
AG
y
=
Draws a line of the division of two data sets
Envelope
(lower)
Lower envelope of G
1
with tolerance of A points
Draws a line that connects the minimum values of a data set. The
tolerance defines the minimum distance (in sampling points) between
two minima, so that the envelope function is able to ignore random
noises.
Envelope
(upper)
Upper envelope of G
1
with tolerance of A points
Draws a line that connects the maximum values of a data set. The
tolerance defines the minimum distance (in sampling points) between
two maxima, so that the envelope function will be able to ignore
random noises.
Exp.
C Ae y
BG
+ =
1
Draws a line of
e
raised to the power of a data set.
Fourier
transform
Discrete Fourier transform of G
1
.
Draws a line of the amplitudes of the harmonics of Fourier transform
vs. frequency.
Frequency
The frequency of G1 (minimum of A points in one cycle).
Draws a line of the frequency of a periodic data set vs. time. The
constant A defines the minimum data points in one cycle.
Integral t G B A y
Δ ∑ + =
1
Draws a line in which each point is the discrete integral of all the
preceding points in a data set.