Potential Fourier Analysis Metrics?

In summary, the conversation discusses using a neural network to process input data from sensors and the best types of frequency input for the network to learn from. The idea of using weighted Fourier transforms is introduced, with the exponential terms in the integrand/summand being weighted to give more importance to recent inputs. The possibility of using this as a feature selection method is also mentioned. The conversation also references existing labs and code that have attempted similar approaches.
  • #1
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So, my friend looked at this post and told me it's beyond confusing. So let me clarify.

Suppose I have a neural network connected to various sensors. How best would I process the input data from the sensor such that a neural network could learn from it best. I'm assuming my network has many, many inputs, so perhaps I could input all types of processed input from my sensors. Forget about processing power limitations for now. I'm simply asking, what types of frequency input would be useful for a neural network to learn from?

I thought of one metric. I was considering weighting recent inputs higher in a Fourier integral as below.Continuous:

[itex] {\bf{F}}_c(j\omega,\alpha,t) = \int^t_{t_0} f(\tau)e^{(\tau -t)\alpha}e^{-j\omega\tau}d\tau, \; \alpha >0 [/itex]

and Discrete (which I would use on a comp):

[itex] {\bf{F}}_d(j\omega,\alpha,n) = T\sum^n_{k=k_0} f_ke^{[k-n]\alpha T}e^{-j\omega Tk}, \; \alpha >0 [/itex]

The idea is that they are weighted Fourier Transforms such that the exponential terms in the integrand and summand are such that since [itex] \tau -t \leq 0, k-n \leq 0 [/itex] ,then [itex] e^{(\tau -t)\alpha} \leq 1, e^{(k -n)T\alpha} \leq 1 [/itex] so that most recent terms are weighted exponentially more.

Then, on the network inputs, I could input values of my weighted Fourier transforms from several values of time and several frequency values, so perhaps a whole matrix of inputs from this frequency metric.

I could even do the same thing for the continuous time inputs

Continous:
[itex] {\bf{f}}_c(\alpha,t) = f(t)e^{(\tau -t)\alpha} [/itex]

Discrete:
[itex] {\bf{f}}_d(\alpha,n) = f_ne^{[k-n]\alpha T}[/itex]

and then, I can get a vector of inputs if I input the last so many sample values from this metric

Would this be a good "feature selection"?
 
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  • #3
There are labs out there that are already attempting to do something very similar to what you are writing about. Analyzing a neural signal with the Fourier Transform is nothing new. How I envisioned back in the day is that each different network responds to a different frequency. So after the Fourier Analysis of a neural network, you would build a filter (input and output) specific to that part of the network. Plenty of example code out there for that.
 

1. What is Fourier analysis and how is it used in potential metrics?

Fourier analysis is a mathematical technique used to decompose a complex function into simpler sinusoidal functions. In potential metrics, Fourier analysis is used to analyze the frequency components of a potential field, allowing for the identification of patterns and potential anomalies.

2. What are the advantages of using Fourier analysis in potential metrics?

One advantage of using Fourier analysis in potential metrics is that it allows for the identification of subtle patterns or anomalies that may not be easily detectable with other methods. It also provides a quantitative measure of the frequency components of a potential field, which can aid in understanding the underlying geological or environmental processes.

3. How do you choose the appropriate Fourier analysis metrics for a specific potential field?

The choice of Fourier analysis metrics depends on the specific characteristics of the potential field being analyzed. Some commonly used metrics include power spectral density, Fourier amplitude spectrum, and Fourier phase spectrum. The appropriate metric should be chosen based on the desired level of detail and the type of potential field being analyzed.

4. Can Fourier analysis be used in other fields besides potential metrics?

Yes, Fourier analysis is a versatile mathematical tool that can be applied in many different fields, including signal processing, image analysis, and physics. In each of these fields, Fourier analysis is used to decompose complex signals or functions into simpler components.

5. Are there any limitations to using Fourier analysis in potential metrics?

While Fourier analysis can provide valuable insights into potential fields, it does have some limitations. For example, it assumes that the potential field is stationary, meaning that the underlying processes do not change over time. It also requires a certain level of data quality and can be affected by noise, so careful processing and interpretation are necessary for accurate results.

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