clausen 1.0.1

Rust implementation of Clausen functions.
Documentation 
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/// reduce ranges of x to [0,pi] for an odd function
pub fn range_reduce_odd(mut x: f64) -> f64 {
    if x < 0.0 {
        x = -x;
    }

    if x >= 2.0*std::f64::consts::PI {
        x = x.rem_euclid(2.0*std::f64::consts::PI);
    }

    if x > std::f64::consts::PI {
        let p0 = 6.28125;
        let p1 = 0.0019353071795864769253;
        x = (p0 - x) + p1;
    }

    x
}


/// reduces range of x to [0,pi] for an even function
pub fn range_reduce_even(mut x: f64) -> (f64, f64) {
    let mut sgn = 1.0;

    if x < 0.0 {
        x = -x;
        sgn = -1.0;
    }

    if x >= 2.0*std::f64::consts::PI {
        x = x.rem_euclid(2.0*std::f64::consts::PI);
    }

    if x > std::f64::consts::PI {
        let p0 = 6.28125;
        let p1 = 0.0019353071795864769253;
        x = (p0 - x) + p1;
        sgn = -sgn;
    }

    (x, sgn)
}