realfft | Real-to-complex and complex-to-real FFT for Rust | Video Utils library

by HEnquist Rust Version: v2.0.1 License: No License

X-Ray Key Features Code Snippets Community Discussions(3)Vulnerabilities Install Support

kandi X-RAY | realfft Summary

realfft is a Rust library typically used in Video, Video Utils applications. realfft has no bugs, it has no vulnerabilities and it has low support. You can download it from GitHub.

This library is a wrapper for RustFFT that enables performing FFT of real-valued data. The API is designed to be as similar as possible to RustFFT. Using this library instead of RustFFT directly avoids the need of converting real-valued data to complex before performing a FFT. If the length is even, it also enables faster computations by using a complex FFT of half the length. It then packs a 2N long real vector into an N long complex vector, which is transformed using a standard FFT. The FFT result is then post-processed to give only the first half of the complex spectrum, as an N+1 long complex vector. The iFFT goes through the same steps backwards, to transform an N+1 long complex spectrum to a 2N long real result. The speed increase compared to just converting the input to a 2N long complex vector and using a 2N long FFT depends on the length f the input data. The largest improvements are for long FFTs and for lengths over around 1000 elements there is an improvement of about a factor 2. The difference shrinks for shorter lengths, and around 30 elements there is no longer any difference.

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Support

realfft has a low active ecosystem.

It has 17 star(s) with 3 fork(s). There are 1 watchers for this library.

It had no major release in the last 12 months.

There are 1 open issues and 3 have been closed. On average issues are closed in 12 days. There are no pull requests.

It has a neutral sentiment in the developer community.

The latest version of realfft is v2.0.1

Quality

realfft has no bugs reported.

Security

realfft has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.

License

realfft does not have a standard license declared.

Check the repository for any license declaration and review the terms closely.

Without a license, all rights are reserved, and you cannot use the library in your applications.

Reuse

realfft releases are available to install and integrate.

Installation instructions are not available. Examples and code snippets are available.

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realfft Key Features

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realfft Examples and Code Snippets

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Community Discussions

Trending Discussions on realfft

Apply FFT to each chunk of 1024 samples

Wrong or no simulation results of FFT when StopTime ist too high in OpenModelica

How can I access multiphase connectors in modelica? (FFT model)

QUESTION

Apply FFT to each chunk of 1024 samples

Asked 2021-May-25 at 01:15

I have 1024 samples and I want to cut them into 32 chunks of 32 and run FFT on each one of them and plot it via a Frequency-Amplitude spectrum, I have most of the code working just the part of applying FFT to each chunk is not working, however I am able to apply FFT to the whole samples array.

I tried doing something like that:

...

ANSWER

Answered 2021-May-25 at 01:15

You have the syntax slightly wrong

Source https://stackoverflow.com/questions/67680233

QUESTION

Wrong or no simulation results of FFT when StopTime ist too high in OpenModelica

Asked 2019-Jul-30 at 10:05

I'm using the realFFT library with OpenModelica to analyze the frequencies in a PWM signal. When I analyze frequencies below 10 kHz everything works fine. But as soon as I set my maximum frequency to more than 10 kHz my simulation either calculates wrong results, crashes or says that it simulated but doesn't show the results.

What I found out so far: I have a the samplePeriod=8.3us and the number of samples ns=6000 for a max frequency of f_max=12kHz and a resolution of f_res=20Hz which results in a stopTime>=(6000-1)*8.3us --> stopTime>=0.05s (according to the library). So I simulated with this stopTime and it worked but when I set stopTime=0.1s it doesn't show any results but says that it simulated fine. When I further increased the stopTime to 0.2s it calculated wrong results.

This doesn't make sense to me, why should it fail with an increased stopTime? Might this be another OpenModelica issue and works fine with Dymola?

Here are my models:

...

ANSWER

Answered 2019-Jul-30 at 10:05

Looks like a bug in OpenModelica. Please open a ticket about it on trac.openmodelica.org.

Problem 1 Huge result files are breaking
When simulating with OpenModelica (v1.14.0-dev-26633-gd9901afc5b) for 0.05 sec simulation time the result mat-file is already 1.06 GB. For 0.1 sec you get around 2.1 GB and a corrupt header.

Problem 2 Wrong results
When you simulate interval [0, 0.2] the solution is completely wrong. Values of y are somewhere around 1.4e+31 and time goes up to 5e+218. Could be because of the broken result file.
But even if you reduce tolerance and interval it won't simulate correctly, maybe because of the huge amount of events.

Works in Dymola 2019, but needs a lot of time to open the result files.

Source https://stackoverflow.com/questions/57185334

QUESTION

How can I access multiphase connectors in modelica? (FFT model)

Asked 2019-Jul-15 at 06:54

I managed to make a FFT model to analyze the frequency of a single phase sine wave voltage source. Now I'm trying to apply my FFT model to the 3-phase domain to analyze the frequencies of a 3-phase voltage source. This looks like the following:

...

ANSWER

Answered 2019-Jul-15 at 06:54

Some things I observed (using Dymola) that could cause some troubles:

The block FFTmultiphase has a Multiphase Interface, which is usually not done in Modelica. Blocks only have causal in-/outputs. I've changed the class from a block to a model. You could as well use a Real input to the model using a sensor to measure the voltage.
Your initial set of equations seem to be over-determined due to the fixed=true in Real y[3](start = fill(0, 3), each fixed = true, each unit = "V");. I would try to remove each fixed = true.

The second seems likelier to cause the problems you describe.

The result seems reasonable then giving A_i = {0,0,4.87,0,0,0} (although I guess it should be 5 for the 3rd entry).

Source https://stackoverflow.com/questions/57006638

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Vulnerabilities

No vulnerabilities reported

Install realfft

You can download it from GitHub.
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