NXT :: descendant of Bitcoin - Updated Information

[Etanllah]

I just realized that Nxt is actually CRAP. I will be selling as much as I can today.

sell all while you can!

correct it for you

Oh, guess it wasn't his last post.

[1715122972]

1715122972

[1715122972]

1715122972

[1715122972]

1715122972

[Emule]

600K sell but green candle, satisfied cfb?

2014-04-02 03:29:20   Sell   0.00006004   29754.000   1.78643
2014-04-02 03:29:20   Sell   0.00006060   17400.348   1.05446
2014-04-02 03:29:20   Sell   0.00006160   118389.000   7.29276
2014-04-02 03:29:20   Sell   0.00006201   5075.243   0.31472
2014-04-02 03:29:20   Sell   0.00006000   5345.000   0.32070
2014-04-02 03:29:20   Sell   0.00006006   5000.000   0.30030
2014-04-02 03:29:20   Sell   0.00006108   1146.980   0.07006
2014-04-02 03:29:20   Sell   0.00006166   5113.393   0.31529
2014-04-02 03:29:20   Sell   0.00006003   32736.000   1.96514
2014-04-02 03:29:20   Sell   0.00006008   3473.701   0.20870
2014-04-02 03:29:20   Sell   0.00006120   20.000   0.00122
2014-04-02 03:29:20   Sell   0.00006200   1000.000   0.06200
2014-04-02 03:29:20   Sell   0.00006000   148773.333   8.92640
2014-04-02 03:29:20   Sell   0.00006006   35678.000   2.14282
2014-04-02 03:29:20   Sell   0.00006101   3005.000   0.18334
2014-04-02 03:29:20   Sell   0.00006164   6327.000   0.39000
2014-04-02 03:29:20   Sell   0.00006002   26784.000   1.60758
2014-04-02 03:29:20   Sell   0.00006007   1536.000   0.09227
2014-04-02 03:29:20   Sell   0.00006112   2284.921   0.13965
2014-04-02 03:29:20   Sell   0.00006170   2922.204   0.18030
2014-04-02 03:29:20   Sell   0.00006000   700.000   0.04200
2014-04-02 03:29:20   Sell   0.00006005   30000.000   1.80150
2014-04-02 03:29:20   Sell   0.00006078   809.476   0.04920
2014-04-02 03:29:20   Sell   0.00006161   59782.494   3.68320
2014-04-02 03:29:20   Sell   0.00006001   30543.000   1.83289
2014-04-02 03:29:20   Sell   0.00006007   38456.000   2.31005
2014-04-02 03:29:20   Sell   0.00006110   22.000   0.00134

[salsacz]

"this was the last post of emule in the nxt forum" good, but there were 2 new posts after. This is like pinarello wrote I am in his ignore list and 5 minutes later he was quoting me

[martismartis]

From blockexplorer:

Balance Total   :   36,032 NXT    USD Equivalent [1]   :   8516523520.00    BTC Equivalent   :   18016000.0000
Transfer Total   :   44    Transfer In   :   37    Transfer Out   :   7
Paid Fees Total   :   17    Amounts In   :   66,413    Amounts Out   :   30,398
Aliases      0    First Transfer   :   24.12.2013    Last Transfer   :   31.03.2014

Bye bye guys, going to buy some country

[LiQio]

still april first? nexern, this one was too obvious 

[Come-from-Beyond]

600K sell but green candle, satisfied cfb?

U r David Copperfield! It's miracle!

[LiQio]

600K sell but green candle, satisfied cfb?

U r David Copperfield! It's miracle!

Reverse Copperfield is more accurate.

Copperfield: pretends to stay here but disappears

Emule: pretends to disappear but stays here

[salsacz]

pls send me some nice message to the testnet acc: 9500913153933294022

- for the video

[Come-from-Beyond]

Reverse Copperfield is more accurate.

Copperfield: pretends to stay here but disappears

Emule: pretends to disappear but stays here

Actually he was joking. April 1st.

[LiQio]

Reverse Copperfield is more accurate.

Copperfield: pretends to stay here but disappears

Emule: pretends to disappear but stays here

Actually he was joking. April 1st.

Dammit, that is like the seventh time - glad that this day is over 

[DrearyUrbanite]

Reverse Copperfield is more accurate.

Copperfield: pretends to stay here but disappears

Emule: pretends to disappear but stays here

Actually he was joking. April 1st.

I thought the joke was that he had a team.

[jl777]

wtf he still uses floating point?  

Indeed he has *bragged about it*.

wtf.... the techdev committee should just come out and say that nobody gets any unclaimed coins bounty from code uzilizing any kind of float data type.

I mean, I appreciate james' dedication and his skill in all the work hes doing, allbeit on no-quite-so trustless-systems work, as most likely they will be replaced by fully decentralized and trustless systems, but we just do NOT need any floating points running around

Currently, I use floating in exactly one place. For calculating allocation of nodecoins. My usage has been approved by CfB. mthcl agreed with my math analysis. Others agreed that for my use case, there is nothing wrong with using floating point.

I make engineering decision based on tradeoffs of accuracy, implementation time, code stability. My assessment was to use 64 bit floating point for allocation. This is because floating point is just as accurate, if not more, when approximating fractions.

The reason integer math is more accurate for financial applications is because there is a least common denominator (satoshi, cent) and so all calculations can be done without errors. As long as you dont overflow.

With pool allocations, you end up with fractions without any reasonable least common denominator. That means you get errors representing it with 64 bit ints or 64 bit floats. However, floats are designed to dynamically adapt to the scale of the numbers while with integers you need a fixed multiplier. The fixed multiplier needs to deal with worst case while at the same time avoiding overflow.

So, using integers for this use case would not be any more accurate and instead open to overflow, or if to avoid overflow you get higher error rates.

The other reason that integer math is preferred in crypto is that all computers end up with the same result. This is important in synchronizing blockchain. however, my code is running on controlled servers and there is no need for synchronizing.

This "never use floating point" requirement seems to be dictating usage of inferior solutions in some use cases. I prefer to think about what I am doing and choose the appropriate solution.

If you have any math based feedback, I am eager to hear it. Superstitous, ban all floating point, is not really constructive.

James

P.S. I could get better accuracy if I used 128 bit floats and near perfect accuracy using 128 bits ints, but I do not trust the code libraries for doing 128 bit math as much as floating point silicon in Intel processors. In any case, do people really need their nodecoins allocated more accurately than .0000000000001 nodecoins?

[opticalcarrier]

Currently, I use floating in exactly one place. For calculating allocation of nodecoins...

Ill just hope that CIYAM didnt know this fact before getting us all riled up

[jl777]

IMO the smart money trades off exchange, preferably using the bitcoin-otc web of trust. Using this forum's trust database is a distant second, considering how many people stay logged in all the time, and how many times bitcointalk itself has been hacked.

The exchanges are better suited for weekend warriors that fancy themselves day traders or small retail purchases.

Mt Gox is only the latest in a long line of cryptoexchanges that have lost significant amount of user funds.

Until the crypto economy is bigger, we probably won't see an exchange that does security and oversight correctly because the space just isn't big enough to afford a reliable service. The exchanges just can't come up with the capital needed to do it properly.

Instead we still have a bunch of pikers that take advantage of the low barrier to entry. They open an exchange and only realize they are in over their heads after their users' funds are stolen.

But who knows, when the floating point decentralized asset exchanges start cropping up, maybe centralized exchanges will be rendered obsolete. Decentralized exchange may be here before a well-funded and well-run centralized exchange emerges.

multigateway has no floating point

[msin]

IMO the smart money trades off exchange, preferably using the bitcoin-otc web of trust. Using this forum's trust database is a distant second, considering how many people stay logged in all the time, and how many times bitcointalk itself has been hacked.

The exchanges are better suited for weekend warriors that fancy themselves day traders or small retail purchases.

Mt Gox is only the latest in a long line of cryptoexchanges that have lost significant amount of user funds.

Until the crypto economy is bigger, we probably won't see an exchange that does security and oversight correctly because the space just isn't big enough to afford a reliable service. The exchanges just can't come up with the capital needed to do it properly.

Instead we still have a bunch of pikers that take advantage of the low barrier to entry. They open an exchange and only realize they are in over their heads after their users' funds are stolen.

But who knows, when the floating point decentralized asset exchanges start cropping up, maybe centralized exchanges will be rendered obsolete. Decentralized exchange may be here before a well-funded and well-run centralized exchange emerges.

multigateway has no floating point

So can someone help James with a review of the C code for multigateway?

[Evil-Knievel]

where is this code?

[jl777]

If I did *criticize his code* then here is what he would do:

"I quit".

Then the "fan base" will say:

"James, we need you"

and he will come back without changing a line of code.

No way.What he needs now is someone who will bring up every possible mistake he made. If there is something wrong,sooner or later it will appear, we need it to happen now.You are both HUGE for the community.

+1

@ james

no personal attack intended james.. or anything of the sort.. if CIYAM has found a flaw then it should be mended.. even BCNext had flaws in his code that were unintended! dont take it as anything other then progression of a mutual goal! as rdanneskjoldr said you are both a huge part of this community.. also i dont know if it is a flaw or just not the best way to do something so i apologies if iv called your code flawed if it is not.

ciyam has had bad experience in past with floating point
now he hates floating point, he has cool demo that proves floating point is braindead
anytime he sees floating point, he remembers horrible past
sometimes floating point is not so bad
sometimes use cases, the cool demo does not apply
floating point, floats
fixed point, rigid
fractions must be approximated, by both
floating point has error rate
integers also have errors with fractions
need least common denominator to use integers without errors
64 bit integers will overflow if fractions used are small enough
nodecoin allocation fractions can be very small
nodecoin allocation might be very big
overflow cannot be avoided with 64 bit, without larger error rate than floating point
128 bit math is not in silicon
errors are pretty small anyway, why risk using software library when CPU does it in silicon
believe me (and CfB), or believe ciyam who has not even looked at my code that does floating point

[jl777]

CIYAM didnt 'find' a flaw.  The limitations and dangers of using floating point math for financial calculations have been well publicized.

Can you give a brief explanation why?

wikipedia has the laymans version

https://en.wikipedia.org/wiki/Floating_point#Accuracy_problems

While floating-point addition and multiplication are both commutative (a + b = b + a and a×b = b×a), they are not necessarily associative. That is, (a + b) + c is not necessarily equal to a + (b + c). They are also not necessarily distributive. That is, (a + b) ×c may not be the same as a×c + b×c:

Like I said, this is a very well known limitation in the financial programming world.

when there is a least common denominator, like cents or satoshi, integers can do errorless calculations
for allocating coins from a pool, integers have errors representing fractions, especially cumulative sums of fractions
you need to look at the source data to determine which has better accuracy
maybe nodecoin pool calculations are not "financial program"?
maybe anything that doesnt have a least common denominator, is not a "financial program"?

Edit: Never using floating point seems to be like not taking full advantage of the hardware, which to me is not optimal. Just be careful, watch error rate, rounding, comparisons, etc. Yes, more work and possible to make mistakes, but this is programming, every line we write can have a bug! Again, if there is a least common denominator without overflow danger, use integers. Otherwise, need to think it through.

[Come-from-Beyond]

Floating-point math is heavily used for financial calculations on supercomputers. If u say that FP is bad then say this to thousands scientists who use it every day.

[jl777]

where is this code?

I am about a week or so away. It is straight C, almost totally self-contained. The only external libs I use are pthread, curl, and maybe zlib

If you are able to review, I will be happy to send you advanced copy

James