Approximates an original function by sines. If the function is "well behaved enough", the approximation is to arbitrary precision.
Fourier's original motivation, and a key application, is solving partial differential equations with the Fourier series.
Can only be used to approximate for periodic functions (obviously from its definition!). The Fourier transform however overcomes that restriction:
The Fourier series behaves really nicely in , where it always exists and converges pointwise to the function: Carleson's theorem.
Some remarks on the language at: cirosantilli.com/china-dictatorship/does-ciro-santilli-speak-chinese
pytorch.org/vision/0.13/models.html has a minimal runnable example adapted to python/pytorch/resnet_demo.py.
That example uses a ResNet pre-trained on the COCO dataset to do some inference, tested on Ubuntu 22.10:This first downloads the model, which is currently 167 MB.
cd python/pytorch
wget -O resnet_demo_in.jpg https://upload.wikimedia.org/wikipedia/commons/thumb/6/60/Rooster_portrait2.jpg/400px-Rooster_portrait2.jpg
./resnet_demo.py resnet_demo_in.jpg resnet_demo_out.jpgWe know it is COCO because of the docs: pytorch.org/vision/0.13/models/generated/torchvision.models.detection.fasterrcnn_resnet50_fpn_v2.html which explains that is an alias for:
FasterRCNN_ResNet50_FPN_V2_Weights.DEFAULTFasterRCNN_ResNet50_FPN_V2_Weights.COCO_V1After it finishes, the program prints the recognized classes:so we get the expected
['bird', 'banana']bird, but also the more intriguing banana.
So far, no new domains have been found with Common Crawl, nor have any existing known domains been found to be present in Common Crawl. Our working theory is that Common Crawl never reached the domains How did Alexa find the domains?
Let's try and do something with Common Crawl.
Unfortunately there's no IP data apparently: github.com/commoncrawl/cc-index-table/issues/30, so let's focus on the URLs.
Using their Common Crawl Athena method: commoncrawl.org/2018/03/index-to-warc-files-and-urls-in-columnar-format/
Sample first output line:So
# 2
url_surtkey org,whwheelers)/robots.txt
url https://whwheelers.org/robots.txt
url_host_name whwheelers.org
url_host_tld org
url_host_2nd_last_part whwheelers
url_host_3rd_last_part
url_host_4th_last_part
url_host_5th_last_part
url_host_registry_suffix org
url_host_registered_domain whwheelers.org
url_host_private_suffix org
url_host_private_domain whwheelers.org
url_host_name_reversed
url_protocol https
url_port
url_path /robots.txt
url_query
fetch_time 2021-06-22 16:36:50.000
fetch_status 301
fetch_redirect https://www.whwheelers.org/robots.txt
content_digest 3I42H3S6NNFQ2MSVX7XZKYAYSCX5QBYJ
content_mime_type text/html
content_mime_detected text/html
content_charset
content_languages
content_truncated
warc_filename crawl-data/CC-MAIN-2021-25/segments/1623488519183.85/robotstxt/CC-MAIN-20210622155328-20210622185328-00312.warc.gz
warc_record_offset 1854030
warc_record_length 639
warc_segment 1623488519183.85
crawl CC-MAIN-2021-25
subset robotstxturl_host_3rd_last_part might be a winner for CGI comms fingerprinting!Naive one for one index:have no results... data scanned: 5.73 GB
select * from "ccindex"."ccindex" where url_host_registered_domain = 'conquermstoday.com' limit 100;Let's see if they have any of the domain hits. Let's also restrict by date to try and reduce the data scanned:Humm, data scanned: 60.59 GB and no hits... weird.
select * from "ccindex"."ccindex" where
fetch_time < TIMESTAMP '2014-01-01 00:00:00' AND
url_host_registered_domain IN (
'activegaminginfo.com',
'altworldnews.com',
...
'topbillingsite.com',
'worldwildlifeadventure.com'
)Sanity check:has a bunch of hits of course. Data scanned: 212.88 MB,
select * from "ccindex"."ccindex" WHERE
crawl = 'CC-MAIN-2013-20' AND
subset = 'warc' AND
url_host_registered_domain IN (
'google.com',
'amazon.com'
)WHERE crawl and subset are a must! Should have read the article first.Let's widen a bit more:Still nothing found... they don't seem to have any of the URLs of interest?
select * from "ccindex"."ccindex" WHERE
crawl IN (
'CC-MAIN-2013-20',
'CC-MAIN-2013-48',
'CC-MAIN-2014-10'
) AND
subset = 'warc' AND
url_host_registered_domain IN (
'activegaminginfo.com',
'altworldnews.com',
...
'worldnewsandent.com',
'worldwildlifeadventure.com'
)One of the most flashy chinese musical instrument!
Wang Jin beats Gao Qiu theme music from The Water Margin
. Source. Design software for synthetic biological circuit.
The input is in Verilog! Overkill?
Pinned article: 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!
Intro to OurBigBook
. Source. 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/derivativeVideo 2. OurBigBook Web topics demo. Source. - 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 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. 
- Infinitely deep tables of contents:
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