Fighting game Updated 2025-07-16
graphviz/node.dot Updated 2025-07-16
graphviz/quotes.dot Updated 2025-07-16
js/matterjs/hello.html Updated 2025-07-16
Hello world adapted from: github.com/liabru/matter-js/wiki/Getting-started/1d138998f05766dc4de0e44ae2e35d03121bb7f2
Also asked at: stackoverflow.com/questions/28079138/how-to-make-minimal-example-of-matter-js-work/76203103#76203103
Renderer questions:
- follow object on viewport: codepen.io/csims314/pen/goZQvG
- draw text: github.com/liabru/matter-js/issues/321
File manager Updated 2025-07-16
Ciro Santilli used to use file managers in the past.
But he finally converted to a shell
cd aliases that auto-ls: github.com/cirosantilli/dotfiles/blob/a51bcc324f0cff0eddd4c3bb8654ec223a0adb7b/home/.bashrc#L1058 Omics Updated 2025-07-16
Each of the omics studies a subset of molecular biology with a data intensive and broad point of view that tries to understand global function or organisms, trying to understand what every biologically relevant molecule does as part of the hole metabolism.
The main omics are:
Omics might be stamp collecting, but maybe it is a bit more like Trading card game/Magic: The Gathering collecting, in which the cards that you are collecting actually have specific uses and interactions, especially considering that most metabolic pathways are analogous across many species.
Once upon a time in the west (1968) Updated 2025-07-16
Open boundary condition Updated 2025-07-16
In the context of wave-like equations, an open-boundary condition is one that "lets the wave go through without reflection".
This condition is very useful when we want to simulate infinite domains with a numerical method. Ciro Santilli wants to do this all the time when trying to come up with demos for his physics writings.
Here are some resources that cover such boundary conditions:
- www.asc.tuwien.ac.at/~arnold/pdf/graz/graz.pdf lots of slides
- hplgit.github.io/wavebc/doc/pub/._wavebc_cyborg002.html mentions them and gives a 1D formula. It mentions that things get complicated in 2D and 3D TODO why.The other page: hplgit.github.io/wavebc/doc/pub/._wavebc_cyborg003.html shows solution demos.
nodejs/sequelize/raw/trigger_count.js Updated 2025-07-16
numpy/fft.py Updated 2025-07-16
Output:With our understanding of the discrete Fourier transform we see clearly that:
sin(t)
fft
real 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
imag 0 -10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 10
rfft
real 0 0 0 0 0 0 0 0 0 0 0
imag 0 -10 0 0 0 0 0 0 0 0 0
sin(t) + sin(4t)
fft
real 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
imag 0 -10 0 0 -10 0 0 0 0 0 0 0 0 0 0 0 10 0 0 10
rfft
real 0 0 0 0 0 0 0 0 0 0 0
imag 0 -10 0 0 -10 0 0 0 0 0 0- the signal is being decomposed into sinusoidal components
- because we are doing the Discrete Fourier transform of a real signal, for the
fft, so there is redundancy in the. We also understand thatrfftsimply cuts off and only keeps half of the coefficients
python/getitem_complex.py Updated 2025-07-16
python/pytorch/matmul.py Updated 2025-07-16
Matrix multiplication example.
Fundamental since deep learning is mostly matrix multiplication.
OpenShot Updated 2025-07-16
Ubuntu 20.10 crash...:
exceptions:ERROR Unhandled Exception
Traceback (most recent call last):
File "/usr/bin/openshot-qt", line 11, in <module>
load_entry_point('openshot-qt==2.5.1', 'gui_scripts', 'openshot-qt')()
File "/usr/lib/python3/dist-packages/openshot_qt/launch.py", line 97, in main
app = OpenShotApp(argv)
File "/usr/lib/python3/dist-packages/openshot_qt/classes/app.py", line 218, in __init__
from windows.main_window import MainWindow
File "/usr/lib/python3/dist-packages/openshot_qt/windows/main_window.py", line 45, in <module>
from windows.views.timeline_webview import TimelineWebView
File "/usr/lib/python3/dist-packages/openshot_qt/windows/views/timeline_webview.py", line 42, in <module>
from PyQt5.QtWebKitWidgets import QWebView
ImportError: /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5: undefined symbol: _ZN4QRhi10newSamplerEN11QRhiSampler6FilterES1_S1_NS0_11AddressModeES2_, version Qt_5_PRIVATE_API python/sphinx/class Updated 2025-07-16
Basic class example.
Optical fiber Updated 2025-07-16
Fiber optics fundamentals by Shaoul Ezekiel
. Source. 2008 at MIT. Theory and demonstration.- youtu.be/0DCrIAxEv_Y?t=560:Terefore, the 1.5 micrometer window truly is the minimum.
- on smaller wavelengths, loss is due to Rayleigh scattering
- on longer wavelengths, loss is due to material absorption
Optical tweezers Updated 2025-07-16
Sample usages:
- quantum computing startup Atom Computing uses them to hold dozens of individual atoms midair separately, to later entangle their nuclei
Optics Updated 2025-07-16
Oracle Corporation Updated 2025-07-16
Evil company that desecrated the beauty created by Sun Microsystems, and was trying to bury Java once and or all in the 2010's.
Their database is already matched by open source e.g. PostgreSQL, and ERP and CRM specific systems are boring.
Oracle basically grew out of selling one of the first SQL implementations in the late 70's, and notably to the United States Government and particularly the CIA. They did deliver a lot of value in those early pre-internet days, but now open source is and will supplant them entirely.
Ordered pair Updated 2025-07-16
Sets are unordered, but we can use them to create ordered objects, which are of fundamental importance. Notably, they are used in the definition of functions.
Order of an element of a group Updated 2025-07-16
There are unlisted articles, also show them or only show them.