101–110 of 233 posts
“Nothing brings fear to my heart more than a floating point number.” - Gerald Jay Sussman Is there any IEEE standards committee working on FP alternative for examples Unum and Posit [1],[2]. [1] Unum & Posit: https://posithub.org/about [2] The End of Error: https://www.oreilly.com/library/view/the-end-of/978148223986...
Earlier quoted context omitted.
On Forth, there's the philosophy of the fixed point: https://www.forth.com/starting-forth/5-fixed-point-arithmeti... With 32 and 64 bit numbers, you can just scale decimals up. So, Torvalds was right. On dangerous contexts (uper-precise medical doses, FP has good reasons to exist, and I am not completely sure). Also, both Forth and Lisp internally suggest to use represented rationals before floating point numbers. Ev…
Those rational numbers fly out the window as soon as your math involves any kind of more complicated trigonometry, or even a square root…
The worst thing that strikes fear into me is seeing floating points used for real world currency. Dear god. So many things can go wrong. I always use unsigned integers counting number of cents. And if I gotta handle multiple currencies, then I'll use or make a wrapper class.
I inherited systems that trade real world money using f64. They work surprisingly well, and the errors and bugs are almost never due to rounding. Those that are also have easy fixes. So I'm always baffled by this "expert opinion" of using integers for cents. It is pretty much up there with "never use python pickle it is unsafe" and "never use http, even if the program will never leave the subnet".
The worst thing that strikes fear into me is seeing floating points used for real world currency. Dear god. So many things can go wrong. I always use unsigned integers counting number of cents. And if I gotta handle multiple currencies, then I'll use or make a wrapper class.
Wouldn't it be better to use a decimal type?
Earlier quoted context omitted.
I inherited systems that trade real world money using f64. They work surprisingly well, and the errors and bugs are almost never due to rounding. Those that are also have easy fixes. So I'm always baffled by this "expert opinion" of using integers for cents. It is pretty much up there with "never use python pickle it is unsafe" and "never use http, even if the program will never leave the subnet".
You can make money modeling buy/sell decisions in floats and then having the bank execute them, but if the bank models your account as a float and loses a cent here and there, it will be sued into bankruptcy.
The worst thing that strikes fear into me is seeing floating points used for real world currency. Dear god. So many things can go wrong. I always use unsigned integers counting number of cents. And if I gotta handle multiple currencies, then I'll use or make a wrapper class.
I've been having an interesting challenge relating to this recently. I'm trying to calculate costs for LLM usage, but the amounts of money involved are so tiny . Gemini 1.5 Flash 8B is $0.0375 per million tokens! Should I be running my accounting system on units of 10 billionths of a dollar?
https://ethereum.stackexchange.com/questions/158517/does-sol...
The worst thing that strikes fear into me is seeing floating points used for real world currency. Dear god. So many things can go wrong. I always use unsigned integers counting number of cents. And if I gotta handle multiple currencies, then I'll use or make a wrapper class.
How do you store negative numbers?
You can think of fixed point as equivalent to ieee754 floats with a fixed exponent and a two’s complement mantissa instead of a sign bit.
Make it work. Make it right. Make it fast.
Earlier quoted context omitted.
I inherited systems that trade real world money using f64. They work surprisingly well, and the errors and bugs are almost never due to rounding. Those that are also have easy fixes. So I'm always baffled by this "expert opinion" of using integers for cents. It is pretty much up there with "never use python pickle it is unsafe" and "never use http, even if the program will never leave the subnet".
you can't accurately represent 10 cents with floats, 0.1 is not directly representable. same with 1 cent, 0.01. Seems like if you do and significant math on prices you should run into rounding issues pretty quickly?