statrs/
prec.rs

1//! Provides utility functions for working with floating point precision
2
3/// Standard epsilon, maximum relative precision of IEEE 754 double-precision
4/// floating point numbers (64 bit) e.g. `2^-53`
5pub const F64_PREC: f64 = 0.00000000000000011102230246251565;
6
7/// Default accuracy for `f64`, equivalent to `0.0 * F64_PREC`
8pub const DEFAULT_F64_ACC: f64 = 0.0000000000000011102230246251565;
9
10/// Returns true if `a` and `b `are within `acc` of each other.
11/// If `a` or `b` are infinite, returns `true` only if both are
12/// infinite and similarly signed. Always returns `false` if
13/// either number is a `NAN`.
14pub fn almost_eq(a: f64, b: f64, acc: f64) -> bool {
15    // only true if a and b are infinite with same
16    // sign
17    if a.is_infinite() || b.is_infinite() {
18        return a == b;
19    }
20
21    // NANs are never equal
22    if a.is_nan() && b.is_nan() {
23        return false;
24    }
25
26    (a - b).abs() < acc
27}
statrs/prec.rs

statrs/
prec.rs
