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Determines what can or cannot happen when multiple queries are running in parallel.
See Section "SQL transaction isolation level" for the most common context under which this is discussed: SQL.
Owned/developed by Google as of 2020.
Early on jumpstarted from several acquisitions, notably Keyhole Inc. and Where 2 Technologies.
Filter graphs are a thing of great beauty. What an amazingly obscure domain-specific language, but which can produce striking results with very little!!!
A quick example from stackoverflow.com/questions/59551013/how-to-generate-stereo-sine-wave-using-ffmpeg-with-different-frequencies-for-eac/77730492#77730492 illustrates some of the fundamentals:
ffplay -autoexit -nodisp -f lavfi -i '
sine=frequency=500[a];
sine=frequency=1000[b];
[a][b]amerge, atrim=end=2
' +--------+
[sine=frequency=500]--->[a]-->| |
| amerge |-->[atrim]-->[output]
[sine=frequency=1000]-->[b]-->| |
+--------+So we see the following syntax patterns:
sine,amergeandatrimare filterssine=frequency=500: the first=says "araguments follow"frequency=500sets thefrequencyargument of thesinefilter- for multiple arguments the syntax is to separate arguments with colons e.g.
sine=frequency=500:duration=2
;: separates statements[a],[b]: sets the name of an edge,: creates unnamed edge between filters that have one input and one output
A list of all filters can be obtained ith:and parameters for a single filter can be obtained with:Related question: stackoverflow.com/questions/69251087/in-ffmpeg-command-line-how-to-show-all-filter-settings-and-their-parameters-bef
ffmpeg -filtersffmpeg --help filter=sineTODO dump graph to ASCII art? trac.ffmpeg.org/wiki/FilteringGuide#Visualizingfilters mentions a
-dumpgraph option, but haven't managed to use it yet.Bibliography:
- ffmpeg.org/ffmpeg-filters.html official documentation
- trac.ffmpeg.org/wiki/FilteringGuide some handy tips from the FFMpeg Wiki
Data that is inscribed in a blockchain as a way to perpetuate the data, rather than to follow the main intended purpose of the given blockchain, e.g. ASCII art instead of financial transactions on the Bitcoin blockchain.
A catalogue for Bitcoin can be found at: Section "Cool data embedded in the Bitcoin blockchain".
Myoglobin structure resolution (1958) by 
Ciro Santilli 35 Updated 2025-01-10 +Created 1970-01-01
Ciro Santilli 35 Updated 2025-01-10 +Created 1970-01-01Published at: a Three-Dimensional Model of the Myoglobin Molecule Obtained by X-Ray Analysis (1958). The work was done at the Cavendish Laboratory.
Simple sines and variants:
- unix.stackexchange.com/questions/82112/stereo-tone-generator-for-linux/536860#536860
- stackoverflow.com/questions/5109038/linux-sine-wave-audio-generator/57610684#57610684
- superuser.com/questions/724391/how-to-generate-a-sine-wave-with-ffmpeg
- stackoverflow.com/questions/59551013/how-to-generate-stereo-sine-wave-using-ffmpeg-with-different-frequencies-for-eac/77730492#77730492
2 second 1000 Hz:
ffmpeg -f lavfi -i "sine=f=1000:d=2" out.wavAhh, Ciro Santilli was certain this was some slang neologism, but it is actually Greek! So funny. Introduced into English in the 19th century according to: www.merriam-webster.com/dictionary/kudo.
Before we get a decent open source integrated development environment, what else can you do?
But also perfect for small one-off files when you don't have the patience to setup said IDE.
vim's defaults are atrocious for the 21st century! Vundle is reasonable as an ad-hoc package manager, but it can't set fixed versions of packages:
The matrix ring of degree n is the set of all n-by-n square matrices together with the usual vector space and matrix multiplication operations.
This set forms a ring.
Main article: DNS Census 2013.
This data source was very valuable, and led to many hits, and to finding the first non Reuters ranges with Section "secure subdomain search on 2013 DNS Census".
Hit overlap:Domain hit count when we were at 279 hits: 142 hits, so about half of the hits were present.
jq -r '.[].host' ../media/cia-2010-covert-communication-websites/hits.json ) | xargs -I{} sqlite3 aiddcu.sqlite "select * from t where d = '{}'"The timing of the database is perfect for this project, it is as if the CIA had planted it themselves!
Attempt at nodejs/sequelize/raw/upsert.js:
- stackoverflow.com/questions/48816629/on-conflict-do-nothing-in-postgres-with-a-not-null-constraint OP unable to provide a minimal exampe, but it is likely the problem
- dba.stackexchange.com/questions/292428/postgresql-upsert-issue-with-not-null-columns
Pinned article: ourbigbook/introduction-to-the-ourbigbook-project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivative - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 4. Visual Studio Code extension tree navigation.
Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.Video 4. OurBigBook Visual Studio Code extension editing and navigation demo. Source. - Internal cross file references done right:
- Infinitely deep tables of contents:
Figure 6. Dynamic article tree with infinitely deep table of contents.Live URL: ourbigbook.com/cirosantilli/chordateDescendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact