Function russell_lab::check::deriv1_backward7

source · 
pub fn deriv1_backward7<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 first derivative using backward difference with 7 points

Given f(x), approximate:

df │   
—— │   
dx │x=at_x