GR_PLOT_FFT(1)

📦
version 3.10.12.0 · 14 versions
, in fedora 43

💖 GR_PLOT_FFT 💖

okay bestie, welcome to gr_plot_fft — it's a User Command, it lives in section 1 of the manual, and it is literally the frequency-domain plotting glow-up for GNU Radio. yes we're doing FFTs today. no cap. ✨

🌸 NAME 🌸

gr_plot_fft — Frequency domain GNU Radio plotting 🦋

🎀 SYNOPSIS 🎀

gr_plot_fft: [options] input_filename

like… that's it. that's the whole vibe. give it a file, it gives you plots. 💅

✨ DESCRIPTION ✨

So here's the tea ☕ — this script takes a GNU Radio complex binary file and shows you the I&Q data versus time and the frequency domain (FFT) plot. Two plots. One icon. 👑

About those y-axis values, because this part matters: they're plotted assuming volts as the amplitude of the I&Q streams, and then converted into dBm in the frequency domain — and yes, the 1/N power adjustment out of the FFT is performed internally, so you don't gotta do it yourself. the script handled it. main character energy fr fr. 🔥

It plots a certain block of data at a time, and you specify that block on the command line with -B or --block. That value defaults to 1000.

Where does it start in the file? That's -s or --start, and it defaults to 0 — aka the start of the file, the very beginning, the origin story. 🌱

And lowkey the most important part: by default, the system assumes a sample rate of 1, so in time, each sample is just plotted versus the sample number. If you want a true time and frequency axis (and you do, bestie, you do), set the sample rate with -R or --sample-rate to the sample rate that was used when capturing the samples. then your axes will actually mean something. slay. 📈

💅 OPTIONS 💅

  • -h, --help — show this help message and exit 🫶 (the classic. the icon. the moment.)
  • -d DATA_TYPE, --data-type=DATA_TYPE — Specify the data type (complex64, float32, (u)int32, (u)int16, (u)int8) [default=complex64] 🧚
  • -B BLOCK, --block=BLOCK — Specify the block size [default=1000] 🎀
  • -s START, --start=START — Specify where to start in the file [default=0] 🌸
  • -R SAMPLE_RATE, --sample-rate=SAMPLE_RATE — Set the sampler rate of the data [default=1.0] ⭐
ngl, the default sample rate of 1.0 is giving "just vibes" — if you want your frequency axis to be real, pass -R. 🙈

🌈 SEE ALSO 🌈

  • gr_plot_fft_c(1)
  • gr_plot_fft_f(1)

and that's the whole page, bestie!! 🦋 you ate. go plot something gorgeous. 💜

this masterpiece is brought to you by gr_plot_fft version 3.10.12.0, dated 2026-01-03 — periodt. 👑✨

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