Bitcoinica - 15169.57 BTC Traded in the last 24 hours

[hmongotaku]

instant millionaire?

[1715361320]

1715361320

[zhoutong]

It has already been fixed. Make sure you don't withdraw your whole balance at once. Because your balanced may be rounded up and you won't have enough for withdrawal.

Thanks!

Floating point numbers are not recommended for storing currency.

For calculations, if your float can not store 123456123456789, you probably are not using enough precision.

I believe he was referring to minimum account balance for withdrawal. i.e. 100 USD, you withdraw 98 USD and the 2 USD is trapped.

-Jonathan

Not exactly. If your balance is $99.999, the system will show $100.00. But you can't withdraw $100.00 because you only have $99.999.

This is what I mean. It's better to withdraw one cent less.

[lemonginger]

So are you storing money as a float or just displaying it rounded to nearest cent?

[zhoutong]

So are you storing money as a float or just displaying it rounded to nearest cent?

We're using Decimal type in our PostgreSQL database. Money are displayed in either 2 d.p. or 4 d.p.

There's no rounding in processing of money. Only the displayed value is rounded.

I will change the withdrawal system to display rounded-down money instead. (Since a $99.999 customer shouldn't be able to withdraw $100.00, the system shouldn't display it as $100.00. We will display it as $99.99 instead.)

Not being able to withdraw $100.00 from a $99.9999999999 account is an indication that we don't use float for money.

[2112]

So are you storing money as a float or just displaying it rounded to nearest cent?

There's nothing wrong with using floats to represent money, so long as the floats used are decimal. Twenty first century brought up the resurgence of decimal floating point. Nowadays pretty much everyone supports them. Check out the following page:

http://speleotrove.com/decimal/

Decimal floating point good! Binary floating point bad!

I think Bitcoinica is implemented mostly in Ruby, so the following will be relevant:

http://ruby-decimal.rubyforge.org/

[quattro]

When will the issue with withdrawals be fixed?

I have been unable to withdraw my funds out of bitcoinica for 12 hours.

Thanks!

It has already been fixed. Make sure you don't withdraw your whole balance at once. Because your balanced may be rounded up and you won't have enough for withdrawal.

Thanks!

That doesn't make sense ... MtGox codes support more than two decimal places.  Why are users unable to withdraw the correct amount?  Why is it being rounded in the first place?

[zhoutong]

When will the issue with withdrawals be fixed?

I have been unable to withdraw my funds out of bitcoinica for 12 hours.

Thanks!

It has already been fixed. Make sure you don't withdraw your whole balance at once. Because your balanced may be rounded up and you won't have enough for withdrawal.

Thanks!

That doesn't make sense ... MtGox codes support more than two decimal places.  Why are users unable to withdraw the correct amount?  Why is it being rounded in the first place?

You may have understood it.

For example a user has $99.99999999 balance, but our site's sidebar can only fit in limited digits, so it's shown as $100.00. If the user assumes that he has $100.00 and wants to take his money out, he won't be able to do so because he doesn't have this amount of money.

So our solution is to show $99.99. If the user explicitly request for the remaining funds, we will be able to check the exact value and fulfill their requests.