How to submit a buy offer that gets incorporated to a bid entry with the same price

Question

An order book shows a bid entry, for example:

12:
amount: "758.2907668"
price: "11.1111111"
price_r: {n: 100, d: 9}

I submit a manageBuyOffer with buyAmount ".01" and price at "11.1111111". I expected the bid entry to increase by .01, and thus to 758.3007668. But instead, the order book returns a new entry at the same price:

13:
amount: "0.3333312"
price: "11.1111111"
price_r: {n: 111111111, d: 10000000}

with the prior entry remaining the same. The order book thus ends up with two bid entries with the same 11.1111111 price.

I would like to know how do I manipulate the buyAmount and price parameters so that the new offer gets consolidated with the first one.

I do not encounter this issue when submitting sell offers.

I reckon it has to do with the price_r, as indeed I do not encounter the problem when I submit the price parameter as a ratio with the same values as those of the first offer, i.e., price: {n: 100, d: 9}. This issue could thus be stated otherwise as: given only the buyAmount and the price parameter in a string format, how does one arrive at the numerator and the denominator of the price so that the new offer gets incorporated with the old offer that has the same price string.

Answer 1

I think the underlying problem is that the number 100/9 has infinite decimal digits and cannot be represented as string. The price you see, 11.1111111 is a truncation of 11.11111111.... = 100/9. When you enter the number 11.1111111 the SDK correctly converts it to its fractional representation 111111111/10000000.

The only way to get around this is to always use fractional prices.