pub trait ValueDifferentiable<T>: PositiveDefiniteKernel<T> where
T: Value, {
fn ln_diff_value(
&self,
params: &[f64],
x: &T,
xprime: &T
) -> Result<(Vec<f64>, f64), KernelError>;
}
pub trait ValueDifferentiable<T>: PositiveDefiniteKernel<T> where
T: Value, {
fn ln_diff_value(
&self,
params: &[f64],
x: &T,
xprime: &T
) -> Result<(Vec<f64>, f64), KernelError>;
}