cross-posted from: https://sh.itjust.works/post/48633930
Normally, we use a place-value system. This uses exponentials and multiplication.
1234 ^^^^ |||| |||└ 4 * 10^0 = 4 ||└ 3 * 10^1 = 30 |└ 2 * 10^2 = 200 1 * 10^3 = 1000 1000 + 200 + 30 + 4 = 1234More generally, let d be the value of the digit, and n be the digit's position. So the value of the digit is d * 10^n^ if you're using base 10; or d * B^n^ where B is the base.
1234 ^^^^ |||| |||└ d = 4, n = 0 ||└ d = 3, n = 1 |└ d = 2, n = 2 d = 1, n = 3
What I came up with was a base system that was polynomial, and a system that was purely exponential, no multiplication.
In the polynomial system, each digit is d^n^. We will start n at 1.
polynomial: 1234 ^^^^ |||| |||└ 4^1 = 4 in Place-Value Decimal (PVD) ||└ 3^2 = 9 PVD |└ 2^3 = 8 PVD 1^4 = 1 PVD 1234 poly = 1 + 8 + 9 + 4 PVD = 22 PVDThis runs into some weird stuff, for example:
- Small digits in high positions can have a lower magnitude than large digits in low positions
- 1 in any place will always equal 1
- Numbers with differing digits being equal!
202 poly = 31 poly PVD: 2^3 + 2^1 = 3^2 + 1^1 8 + 2 = 9 + 1 = 10
In the purely exponential system, each digit is n^d^. This is a bit more similar to place value, and it is kind of like a mixed-base system.
1234 ^^^^ |||| |||└ 1^4 = 1 ||└ 2^3 = 8 |└ 3^2 = 9 4^1 = 4 1234 exp = 4 + 8 + 9 + 1 PVD = 22 PVDHowever it still runs into some of the same problems as the polynomial one.
- Small digits in high positions can have a lower magnitude than large digits in low positions (especially if the digit is 1)
- The digit in the ones place will always equal 1
- Numbers with differing digits can still be equal
200 exp = 31 exp PVD: 3^2 = 2^3 + 1^1 9 = 8 + 1
So there you have it. Is it useful? Probably not. Is it interesting? Of course!
Yes, that's the main problem with this, how numbers with different digits can be equal. It wasn't intended for anything serious though, just a fun thought experiment.
I didn't come up with this entirely on my own. I encountered a number system on Everything2 or Reddit, and it was described as a "prime-factorization based number system" IIRC; but it was much more complicated than this and I can't remember how it works.