Function russell_lab::check::deriv2_forward8

source · 
pub fn deriv2_forward8<F, A>(
    at_x: f64,
    args: &mut A,
    f: F
) -> Result<f64, StrError>
where
    F: FnMut(f64, &mut A) -> Result<f64, StrError>,
Expand description

Approximates the second derivative using forward difference with 8 points

Given f(x), approximate:

d²f │   
——— │   
dx² │x=at_x