java nth root calculator

BigInteger & BigDecimal nth Root Calculator

This algorithm was tested with numbers up to 20000 digits but it can work with bigger numbers.

The result can be a BigInteger if the result is an exact integer or a BigDecimal.

Example: integer: 12345678901234567890 ^ 1000

number of digits:19091

root result : 12345678901234567890

nth_root:1000

calculation time: 284ms on my i7 6500U (laptop).

Algorithm:

1. I make a fast root approximation using logarithms: root = antilog(log(number)/n)

2. I use the approximation in numerical methods to figure out the real root:

   -Example numerical methods: Nth root order 3 --> Xk+1=Xk*[((n+1)*r + (n-1)Xk^n)/(n-1)*r + (n+1)*xk^n]

How to use it

In the test package you can see one example about how to use this al algorithm

Enjoy it!!

If you think that my work deserves a donation, you can do it: https://sbesada.github.io/