Constrained Hermite TLS for Mesh-free Derivative Estimation Near and On Boundaries

R Upper-triangular matrix from QR decomposition v Direction unit vector: vj ; j ∈ [1, N ] Vinf Freestream velocity W Combined weight matrix Wb Derivative observation weight matrix: Wb i,j ≡ wi δi,j Wf Function observation weight matrix: Wf i,j ≡ wi δi,j x Vector of input quantities to f : xj ; j ∈ [1, N ] θ, φ Spherical polar coordinates {d} Vector of Taylor series derivatives: dk ; k ∈ [1, t] {f} Vector of function difference observations: Δfi ; i ∈ [1, nf ] {H} CHTLS solution coefficient vector (with F and G) {h} Vector of directional derivative observations: hi ; i ∈ [1, nb ] {V0 } Direction derivative v0 rearranged to order corresponding to {d} a Index of differentiation variable