Monthly Archives: May 2021

In this article I’m going to explain how to calculate a real-number based FFT using FFTW, providing the source code. First, though, I will introduce some important concepts. Then I will provide code with comments within it. I will also provide a header containing sample data from a single channel sound file whose frames have been converted into double values. The samples are of a 440 Hz sine tone mixed with noise. I exported the raw sound data from Audacity, and used the od program (GNU coreutils), to convert the raw data to double precision floating point numbers, and outputted that into a file that I could reformat into the header, “a_with_noise.h”. Acknowledgements Thanks Jake for pointing me in the right direction, providing sample code for computing a complex number FFT. Assumptions Programming explanations and examples are for the C programming language. You understand what a FFT is used for.…

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Out with the old, in with the new. My old website, that used a Python CMS and ran on Apache on an older version of Debian, is out, and has been replaced with WordPress and Docker containers running on a newer version of Debian 10. Boy, that was a process; deploying Docker containers in production without proper verification can be challenging. Just because something works great locally doesn’t mean it will on a production server, and I learned this the hard way. How I Did It I had to reinstall my OS: Debian 10. I quickly became apparent software for Debian is older than what is available for Arch Linux, where I tested my Docker containers. I did quite a bit of set up on my local machine, before copying it to my server and using docker-compose to launch my containers. After that, there was tweaking to various different configuration…

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