| lib.rs |
A collection of numeric types and traits for Rust.
This includes new types for big integers, rationals, and complex numbers,
new traits for generic programming on numeric properties like `Integer`,
and generic range iterators.
## Example
This example uses the BigRational type and [Newton's method][newt] to
approximate a square root to arbitrary precision:
```
# #[cfg(any(feature = "alloc", feature = "std"))]
# mod test {
use num::FromPrimitive;
use num::bigint::BigInt;
use num::rational::{Ratio, BigRational};
# pub
fn approx_sqrt(number: u64, iterations: usize) -> BigRational {
let start: Ratio<BigInt> = Ratio::from_integer(FromPrimitive::from_u64(number).unwrap());
let mut approx = start.clone();
for _ in 0..iterations {
approx = (&approx + (&start / &approx)) /
Ratio::from_integer(FromPrimitive::from_u64(2).unwrap());
}
approx
}
# }
# #[cfg(not(any(feature = "alloc", feature = "std")))]
# mod test { pub fn approx_sqrt(n: u64, _: usize) -> u64 { n } }
# use crate::test::approx_sqrt;
fn main() {
println!("{}", approx_sqrt(10, 4)); // prints 4057691201/1283082416
}
```
[newt]: https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method
## Compatibility
The `num` crate is tested for rustc 1.60 and greater. |
3086 |