exp, exp2 functions are not working as expected

[felix0888]

Trying the exp, exp2 functions, I noticed that those functions are not working the way I expected.

Actually, I was expecting x.exp to return e^x with some zeros, but not. I send you some test data and the result I'm getting.

uint x = 1; // test input
return x.exp();

x                 x.exp()
1                 1000000000000000000
2                 1000000000000000002
3                 1000000000000000002
10                1000000000000000009
100               1000000000000000099
...

Similar result when trying exp2 function.
Any misunderstanding on my side?

[PaulRBerg]

Any misunderstanding on my side?

Yup. This is a fixed-point math library, which means that numbers are assumed to have 18 decimals. Always.

In your case, when you set x to 1, in normal numbers that's actually 0.000000000000000001. The result you got is correct: taking e to the power of 0.000000000000000001 gives you ~1.

Please refer to the README, this is explained thoroughly there.

[felix0888]

Absolutely, I got what you mean.
Thank you for your quick help.

[PaulRBerg]

Happy to help.