STFT-GPR-method: Short-time Fourier Transform (STFT)
In emanuelhuber/RGPR: Ground-penetrating radar (GPR) data visualisation, processing and
delineation
STFT,GPR-method R Documentation
Short-time Fourier Transform (STFT)
Description
The STFT can be seen as a sliding window that takes at each sample-window
a Fast-Fourier Transform of the windowed signal.
Usage
## S4 method for signature 'GPR'
STFT(x, w)
Details
DFT with N = 128:
The time domain signal is Contained in the array:
x[1] to x[128]. The frequency domain signals are contained in the
two arrays: ReX[1] to ReX[65], and to ImX[1] to ImX[65].
Notice that 128 points in the time domain corresponds to 65 points in each
of the frequency domain signals.
That is, N points in the time domain corresponds to points in the
N/2 + 1 frequency domain (not N/2 points).
Forgetting about this extra point is a common bug in DFT programs.
ReX[1] holds the average value of all the points.
ImX[1] is equal to zero.
In R, the fft returns: c(ReX[1:(N/2 + 1)], ImX[(N/2 + 1):2]) (??)
emanuelhuber/RGPR documentation built on May 13, 2024, 9:31 p.m.
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| STFT,GPR-method | R Documentation |
Short-time Fourier Transform (STFT)
Description
The STFT can be seen as a sliding window that takes at each sample-window a Fast-Fourier Transform of the windowed signal.
Usage
## S4 method for signature 'GPR'
STFT(x, w)
Details
DFT with N = 128: The time domain signal is Contained in the array: x[1] to x[128]. The frequency domain signals are contained in the two arrays: ReX[1] to ReX[65], and to ImX[1] to ImX[65]. Notice that 128 points in the time domain corresponds to 65 points in each of the frequency domain signals. That is, N points in the time domain corresponds to points in the N/2 + 1 frequency domain (not N/2 points). Forgetting about this extra point is a common bug in DFT programs. ReX[1] holds the average value of all the points. ImX[1] is equal to zero. In R, the fft returns: c(ReX[1:(N/2 + 1)], ImX[(N/2 + 1):2]) (??)
R Package Documentation
Browse R Packages
We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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