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