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Incomplete AMM calculations sample code

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mDuo13
2024-04-10 15:55:05 -07:00
parent 1c205a1c25
commit 43ebddb05a
1 changed files with 26 additions and 11 deletions
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37
_code-samples/amm-calculator/js/amm-calculator.js
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@@ -3,14 +3,24 @@ const BigNumber = require('bignumber.js')
/*
* Convert a trading fee to a value that can be multiplied
* or divided for fee calculations.
* by a total to "subtract" the fee from the total.
* @param tFee int {0, 1000}
* 1 = 1/100,000 or 1000 = 1% fee
* such that 1 = 1/100,000 and 1000 = 1% fee
* @returns BigNumber (1 - fee) as a decimal
*/
function feeMult(tFee) {
return BigNumber(1).minus( feeDecimal(tFee) )
}
/*
* Convert a trading fee to a decimal BigNumber value,
* for example 1000 becomes 0.01
* @param tFee int {0, 1000}
* such that 1 = 1/100,000 and 1000 = 1% fee
* @returns BigNumber(fee) as a decimal
*/
function feeDecimal(tFee) {
const AUCTION_SLOT_FEE_SCALE_FACTOR = 100000
return BigNumber(1).minus( (BigNumber(tFee).dividedBy(AUCTION_SLOT_FEE_SCALE_FACTOR)) )
return BigNumber(tFee).dividedBy(AUCTION_SLOT_FEE_SCALE_FACTOR)
}
/*
@@ -42,19 +52,22 @@ function swapOut(asset_out_bn, pool_in_bn, pool_out_bn, trading_fee) {
/*
* Calculates the necessary bid to win the AMM Auction slot, per the pricing
* algorithm defined in XLS-30 section 4.1.1.
* @returns BigNumber - the minimum amount of LP tokens to win the auction slot
*/
function auctionPrice(old_bid, time_interval) {
const min_bid = 123456 // @@TODO: figure out real min bid
function auctionPrice(old_bid, time_interval, trading_fee, lpt_balance) {
const tfee_decimal = feeDecimal(trading_fee)
const min_bid = BigNumber(lpt_balance).multipliedBy(tfee_decimal).dividedBy(25)
const b = BigNumber(old_bid)
if (time_interval >= 20) {
return min_bid
}
if (time_interval <= 1) {
return (old_bid * 1.05) + min_bid
return b.multipliedBy(BigNumber("1.05")).plus(min_bid)
}
const t60 = BigNumber(0.05).multipliedBy(time_interval).exponentiatedBy(60)
return B * 1.05 * (1 - t60) + min_bid
const t60 = BigNumber("0.05").multipliedBy(time_interval).exponentiatedBy(60)
return b.multipliedBy("1.05").multipliedBy(BigNumber(1).minus(t60)).plus(min_bid)
}
async function main() {
@@ -80,7 +93,7 @@ async function main() {
const amm_info = (await client.request({"command": "amm_info", "asset": from_asset, "asset2": to_asset}))
console.dir(amm_info, {depth: null})
const amm_account = amm_info.result.amm.account
const lpt_code = amm_info.result.amm.lp_token.currency
const lpt = amm_info.result.amm.lp_token
const pool_drops = amm_info.result.amm.amount // XRP is always first if the pool is token←→XRP
const pool_tst = amm_info.result.amm.amount2
const full_trading_fee = amm_info.result.amm.trading_fee
@@ -119,8 +132,10 @@ async function main() {
const potential_savings = from_amount - discounted_from_amount
console.log(`Potential savings: ${xrpl.dropsToXrp(potential_savings)} XRP`)
// Calculate the cost of winning the auction slot, in LP Tokens.
const auction_price = auctionPrice(old_bid, time_interval)
// Calculate the cost of winning the auction slot, then convert it to XRP
const auction_price = auctionPrice(old_bid, time_interval, full_trading_fee, lpt.value)
console.log(`Auction price: ${auction_price} LP Tokens`)
// @@TODO: figure out how to convert auction_price from LPT to input asset.
// Done.