To: bitcoin-dev@lists.linuxfoundation.org
References: <358752cc-48f6-eef8-ae9a-e17a0651ed52@murch.one>
From: Daniel Weigl <Daniel.Weigl@mycelium.com>
Message-ID: <1aa41a90-2cc6-36c8-d9c5-67d52befabbe@mycelium.com>
Date: Thu, 22 Sep 2016 11:33:18 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
	Thunderbird/45.2.0
MIME-Version: 1.0
In-Reply-To: <358752cc-48f6-eef8-ae9a-e17a0651ed52@murch.one>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Subject: Re: [bitcoin-dev] On-going work: Coin Selection Simulation
Precedence: list

Hi,

Is your simulation code available somewhere?

I was just wondering why mycelium generates a very big UTXO set for <1000sat, because change outputs will never be smaller than 
5460sat (=TransactionUtils.MINIMUM_OUTPUT_VALUE). If the change would be lower, it simply is skipped and added to the miner fee:
	-> https://github.com/mycelium-com/wallet/blob/master/public/bitlib/src/main/java/com/mrd/bitlib/StandardTransactionBuilder.java#L334

Does your simulation account for that?

It might also be that the small UTXO came from external tx and we never spend them, bec. of pruning/privacy. Not sure how we could optimize that.

Cheers,
Daniel

On 2016-09-21 14:58, Murch via bitcoin-dev wrote:
> Hi,
> 
> I'm currently compiling my Master's thesis about Coin Selection and my
> presentation proposal to Scaling Bitcoin has been accepted.
> 
> For my thesis, I have analyzed the Coin Selection problem, created a
> framework to simulate wallet behavior on basis of a sequence of
> payments, and have re-implemented multiple coin selection strategies of
> prominent Bitcoin wallets (Bitcoin Core, Mycelium, Breadwallet, and
> Android Wallet for Bitcoin).
> 
> As the Scaling Bitcoin site suggests that research should be made
> available to this mailing list, I would like to invite you to have a
> look at:
> 
> http://murch.one/wp-content/uploads/2016/09/CoinSelection.pdf
> 
> The PDF (176 kB) contains a two page description of my on-going work,
> including preliminary simulation results, and three figures showing the
> simulated wallets' UTXO compositions at the end of the simulation.
> 
> I can provide further information as requested, and would welcome any
> feedback.
> 
> →→ If anyone has another sequence of incoming and outgoing payment
> amounts at hand that I could run my simulation on, I'd love to hear
> about it.
> 
> Regards
> 
> Murch
> 
> 
> 
> 
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>