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πFS

github.com

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101–110 of 224 posts

Re: πFS

#101

Post by oofbey »

windward wrote: post #96

>One of the properties that π is conjectured to have is that it is normal conjectured Glad to see one of my pet points of pedantry come up. No non-constructed irrational number has never been proven to be normal or disjunctive.

That’s a lot of negatives!

Re: πFS

#102

Post by bilsbie »

I’d guess even the index in pi for my phone number would be more digits than the phone number.

So not really a compression scheme.

Re: πFS

#103

Post by jamwise »

quirino wrote: post #100
jamwise wrote: post #31

Reminds me of when I tried to use the library of babel as a data compression tool. It led me down a fun rabbit hole and was my first introduction to information theory. The conclusion being that you basically need the same amount of data to represent the address of your data as the data itself, so it's not really effective at compression, just a fun thought experiment. The cool part of this in modern times is that LL…

3Blue1Brown just released a viduo about this Intelligence-Compression connection. https://youtu.be/l6DKRf-fAAM

The idea was fresh in my mind because I watched this yesterday. Great video, the illustrations and intuition-building of the compressability of information was so good! I'm so grateful for 3Blue1Brown.

Re: πFS

#104

Post by dekhn »

emptyroads wrote: post #79

Reminds me of nsafs, the National Security Agency Filesystem ("free" because the government pays for it) - https://github.com/freedomtools/nsafs

I once interviewed for a company and the interviewer was telling me how he (a vc) funded a project to generate large streams of random numbers; you would select an index at random, share that private key with somebody, and then the subsequent text could be used as a one-time-pad. NSA would be forced to buffer/save the entire stream, which could be generated at GB/sec, if they wanted to decrypt.

It didn't seem very practical.

Re: πFS

#105

Post by russfink »

mondrian wrote: post #55
adzm wrote: post #12

It is worth noting that as the length of data increases it becomes extremely unlikely that the index and length of the sequence within pi would actually be smaller than the data.

The index of your 20 line file is

Unless, in turn, you locate the index itself in pi at a much smaller index. And so on...

Find k candidate indices for your data, then locate each of them. If the smallest one is a significantly smaller index space, repeat.

Re: πFS

#106

Post by ndiddy »

MisterTea wrote: post #8

Reminds me of: https://www.spronck.net/sloot.html Further reading: https://en.wikipedia.org/wiki/Sloot_Digital_Coding_System

I looked into this a bit a while ago, what Sloot did was at least a little novel. Basically the way his encoding scheme actually worked was that it would store each line of video into a database, encode each video frame as a series of line lookups, and then store that encoded frame into another database. Then each video is a series of frame lookups. When you hear accounts of him being able to demo smooth playback of 16 videos at once on late 90s hardware, this is how he did it. Because each frame is a series of line lookups, splitting the screen horizontally 16 times and playing 16 videos at once is not any more taxing than playing a single video fullscreen. Similarly, he was able to fast-forward and rewind smoothly because each frame is individually decoded, it's not like traditional video compression where you have to calculate differences from each keyframe. Playing at 2x speed was not any more taxing than 1x speed. Of course he never would have been able to store a video file in 8KB or whatever, but this meant that (for example) if you had a whole season of a TV show in your database, the opening and ending credits would only be stored once.

Re: πFS

#107

Post by mikestew »

oofbey wrote: post #101
windward wrote: post #96

>One of the properties that π is conjectured to have is that it is normal conjectured Glad to see one of my pet points of pedantry come up. No non-constructed irrational number has never been proven to be normal or disjunctive.

That’s a lot of negatives!

One of which probably needs to go away.

Re: πFS

#109

Post by dekhn »

actusual wrote: post #67

This is why I got pi tattooed. It's a tattoo of all tattoos.

yes, but can you get a tattoo of all tattoos that do not contain themself?

Re: πFS

#110

Post by hatthew »

adzm wrote: post #12

It is worth noting that as the length of data increases it becomes extremely unlikely that the index and length of the sequence within pi would actually be smaller than the data.

TFA addresses this

> Now, we all know that it can take a while to find a long sequence of digits in π, so for practical reasons, we should break the files up into smaller chunks that can be more readily found.

> In this implementation, to maximise performance, we consider each individual byte of the file separately, and look it up in π.

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