AuroraLantean
commented
4 months ago @uchu @Warchant @akorchyn
After some research, for financial calculation it is recommended to use integers to do all calculation, then we round up to what we want at division: https://www.pullrequest.com/blog/precision-matters-why-using-cents-instead-of-floating-point-for-transaction-amounts-is-crucial/
Define "dp" as decimal precision... E.g. USD has 2 dp for example $ 2.37
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Addition/Subtraction: a tokenA 2dp balance adds or subtracts a tokenB 3dp balance: Convert them into integers using the bigger dp E.g. 0.01+0.001 => (10 + 1)x1000 = 11 and dp of 3 => 0.011, and that is 3 dp Result dp = the max dp between them
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Multiplication: a tokenA 2dp balance multiplies a tokenB 3dp balance: Convert them into integers using each of their dp E.g. 0.01*0.001 => (1x1)/(100 x1000) => 1 and dp of 5 => 0.00001 and that is 5 dp. The result dp = the sum of those dp
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Division: a tokenA 3dp balance is divided by a tokenB 2dp balance: Convert them into integers using the bigger dp 3dp / 2dp => 2dp( top and bottom both are multiplied by the bigger of 10**dp => 0 dp / 0 dp => dp1-dp2 ) E.g. 0.001/0.10 => 1/10 => 0.1 The result dp = 3-2 = 1
2dp / 3dp => 2dp( top and bottom both are multiplied by the bigger of 10**dp => 0 dp / 0 dp => dp1-dp2 ) E.g. 0.01/0.001 => 10/1 = 10 The result dp = 0
E.g. 0.01/100.000 => 10/100000 = 0.0001 The result dp = ?? ... Division in math is always strange... I think we can decide how much dp we want after division
uchu
akorchyn
olenaboosty
We need to format all numbers in DEX, so it is more easy to read long numbers. For example: 1,000,000.00 (with 2 decimals precision by default)
We need to implement an ability to use custom decimal precision. In the simplest way it can be just a harcoded map: token: price precision, amount precision. In that way we can correctly display tokens that have typically low price or quantities.
Examples 0.0000012 BTC 30000.56 some token 150.50 USDT
While amounts can be like 1100.00 Usdt when displayed in the interface, the actual values can be like 1100.000091. we have to display the full exact amount on mouse hover (simple html tooltip is enough for now) and in any input fields of the forms. Also in the sections where we make transactions.
Let's discuss the parts of the UI where full or alternative formats can be needed, unless it is obvious.
DOD:
All numbers, prices and amounts should be rounded and formatted correctly.