Wrong results with symbolic derivative using sympy
I am trying to realize the covariance matrix using the non-stationary kernel (Gibbs kernel). The kernel function is defined as(sorry I don’t know how to type in LaTex here)
Covariance matrix not positive definite with symbolic derivative involved
I am trying to realize the covariance matrix using the non-stationary kernel (Gibbs kernel). The kernel function is defined as(sorry I don’t know how to type in LaTex here)