confuseling
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pifs, the data free file system

Wed Sep 25, 2013 5:42 pm

https://github.com/philipl/pifs

Thought you guys and gals might appreciate this :D
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ghans
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Re: pifs, the data free file system

Thu Sep 26, 2013 8:40 am

...
You should get this patented immediately !

ghans
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morphy_richards
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Re: pifs, the data free file system

Thu Sep 26, 2013 10:36 am

So ... getting my head around this ....

Because Pi is an infinite, non repeating (sic) decimal - meaning that every possible number combination exists somewhere in pi....

Every conceivable combination of data that you could ever make, ever existed or that could ever be created in the future exists somewhere within it ...

<edit> And they've made a program that can find it ... ?

:shock:

!
Last edited by morphy_richards on Thu Sep 26, 2013 11:23 am, edited 1 time in total.

confuseling
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Re: pifs, the data free file system

Thu Sep 26, 2013 10:46 am

Sorry, to clarify, I didn't write it - just found it and thought it was funny.
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AndrewS
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Re: pifs, the data free file system

Thu Sep 26, 2013 11:33 am

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.
LOL

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morphy_richards
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Re: pifs, the data free file system

Thu Sep 26, 2013 11:41 am

AndrewS wrote: LOL
Fair dues though, they say
"Why is this thing so slow? It took me five minutes to store a 400 line text file!" ... "Well, this is just an initial prototype"
I wonder how much space the "metadata" uses but it's still impressive given that 400 lines of text takes up no space whatsoever.
I'm going to have a play with this at lunch time and report back :)

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Re: pifs, the data free file system

Thu Sep 26, 2013 11:45 am

Reminds me of the program source code encoded into a prime number:

http://en.wikipedia.org/wiki/Illegal_prime

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morphy_richards
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Re: pifs, the data free file system

Thu Sep 26, 2013 2:18 pm

Havent been able to make it :(
I installed autoconf and tried their instructions but no good so tried

Code: Select all

autoconf configure.ac > configure
But only got
configure.ac:4: error: possibly undefined macro: AM_CONFIG_HEADER
If this token and others are legitimate, please use m4_pattern_allow.
See the Autoconf documentation.
configure.ac:5: error: possibly undefined macro: AM_INIT_AUTOMAKE

Which seems a shame. Would very much like to see it work nevertheless.

wimble
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Re: pifs, the data free file system

Thu Sep 26, 2013 2:43 pm

Somewhere, deep, deep in the base-256 (ie. ASCII) expansion of pi, there exists the entire text of Carl Sagan's "Contact"...

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Burngate
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Re: pifs, the data free file system

Thu Sep 26, 2013 3:40 pm

Why Pi?
Why not e?

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RaTTuS
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Re: pifs, the data free file system

Thu Sep 26, 2013 3:49 pm

Pi/e ;)
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drgeoff
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Re: pifs, the data free file system

Thu Sep 26, 2013 5:14 pm

Seems to overlook the fact that although the infinitely long representation of pi can contain every possible file, the index number (ie the position of the start of that file within the representation) must also be infinitely large (ie require an infinite number of bits to represent it). Therefore there is no compression - quite the opposite.

(Yes I know it isn't supposed to be taken 100% seriously. Or even 1%!)

Sadly, over the years I've had to deal with more than one deluded person who tried to get my employer interested in his algorithm which he claimed could perform lossless compression on any data.

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AndrewS
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Re: pifs, the data free file system

Fri Sep 27, 2013 12:56 am

drgeoff wrote:Sadly, over the years I've had to deal with more than one deluded person who tried to get my employer interested in his algorithm which he claimed could perform lossless compression on any data.
That's easy! Just strip out all the binary zeroes - there's no point storing zero because zero means nothing! Should give 50% compression, on average :lol:

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morphy_richards
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Re: pifs, the data free file system

Fri Sep 27, 2013 8:35 am

I'm going to stick my head over the parapet a bit here because I love the idea and I'm a hopeless romantic. Given that I frequently embarrass myself by getting stuff wrong in this community, the way I see it there is no danger of damaging my reputation as my reputation is already hopeless :D
So, apparently the program uses the Bailey–Borwein–Plouffe formula which :
can directly calculate the value of any given digit of π without the need to calculate the preceding digits
Image
(There's also a C++ implementation of this formula in stack overflow here so I'm satisfied it's real)
So, it seems it is mathematically proven that you can now calculate any digit(s) of Pi irrespective of where they lie between 0 and infinity. So, it sounds promising.

This bit makes sense to me. However what doesn't make sense to me is their method for encoding (embedding?) your data into Pi. They say:
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.
OKay ... So every byte of the program needs an index - where the data for that byte begins and ends in Pi. Surely the index for each byte that's saved in metadata on your local machine would need to be at least one byte? :? (perhaps they are waiting for Snowden to pass blueprints of the NSA/GCHQ quantum computer into the public domain so that would we e able to find a long string of digits in Pi near instantaneously? (in which case any data of any size could be represented by two numbers, a start and stop position) ;) )

I really wish I could run their program myself, irrespective of whether it actually really saves space or not it's a suitably fascinating topic. I t would generate a really good discussion with my GCSE Computer Science class this afternoon so even if it is no practical use it has the potential to be a great cognitive / computational thinking exercise.
Sadly my skills are not up to it, their instructions ...
./configure
make
make install
... don't work on a standard Debian/Ubuntu installation. Not sure if it's my own ineptitude or a problem on their part. :?

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morphy_richards
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Re: pifs, the data free file system

Mon Sep 30, 2013 9:15 am

Just need to remove -Werror from the Makefile and it will work. GCC has too many warnings turned on by default.
It definitely is a joke by the way ;) But I still maintain that it could be a fabulous little thinking exercise.
Now that I can make it work I'm looking forward to 'wasting' (well not exactly wasting but it's certainly not on the curriculum) an hour with my class on this.

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RaTTuS
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Re: pifs, the data free file system

Mon Sep 30, 2013 9:23 am

push the updates back via git ;--p
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confuseling
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Re: pifs, the data free file system

Mon Sep 30, 2013 11:07 am

Or just tell them where the diff is in Pi, of course... ;)

ETA: also, while we're just being silly:

http://turner.faculty.swau.edu/mathemat ... stery.html

:D
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