All Questions
Tagged with fourier-transform frequency
9 questions
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475
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How to calculate harmonic equations from a complex wave
I’m working through an online example that explains spectral analysis in R. Let’s say you have a complex wave:
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- 77
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Relation between Fourier transforms and coherence of signals
My overall aim is to compare the edges of two images by comparing their Fourier Transforms (FFT) and to calculate one number as a key performance indicator that describes how much they are similar to ...
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3
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4k
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Spectral Analysis in R - the periodogram
I am doing a spectral analysis in R using the spec.pgram() function. Suppose I have observations for $y_1$ to $y_n$ which are a time series with annual observations....
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How to measure a mean frequence of fft transform
I have this time series (utilization of app by day of an user)
And this fourier transform of the above time series
How can I extract one number that express the mean frequency of this time series?
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- 111
1
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detecting change point in the time series on a 2 dimensional space
I have a 2 dimensional geographic space. There are crime events occuring at different regions in the space over time. I am looking particularly at property crimes like burglary. If I look at the time ...
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Can I Use DFT To Find The Most Common Frequency?
I have a collection of data which measures the change in state of a device which records information. I basically record the time a new observation is made on the device. I want to collect the data ...
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0
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206
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Suggested algorithms for time series analysis of sporadic events
I have a series of sporadic, discrete time series events that appear to occur in shorter interval clusters and I am looking for a way to determine the frequencies at which the events occur. None of ...
- 175
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How to measure the period of an oscillation with least error?
I have a question about analyzing the data from a coupled pendulum.
I have measured the amplitude $\psi(t)$ which is expected to be a beat and I want to measure the period. The ideal plot would be ...
- 150
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Discrete Fourier Transform and uneven sampling
In this blog article
an example is given of one can use the DFT to detect frequencies much higher than the sample rate.
In the comments sections I asked how it was done, since DFT normally requires ...
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