Number of integration points
Hi, I am not exactly sure if this is the approparite place, but I find some doubts with the integration points with Hexahedron 8 element using the latest Gmsh SDK, consider the following MWE in Julia:
julia> include("gmsh.jl")
Main.gmsh
julia> using Printf
julia> gmsh.initialize()
julia> for i in 1: 20
nodes, weights = gmsh.model.mesh.getIntegrationPoints(5, "Gauss" * string(i))
@printf "Order: %d, Number of Points: %d\n" i length(weights)
end
Order: 1, Number of Points: 6
Order: 2, Number of Points: 34
Order: 3, Number of Points: 8
Order: 4, Number of Points: 27
Order: 5, Number of Points: 27
Order: 6, Number of Points: 64
Order: 7, Number of Points: 64
Order: 8, Number of Points: 125
Order: 9, Number of Points: 125
Order: 10, Number of Points: 216
Order: 11, Number of Points: 216
Order: 12, Number of Points: 343
Order: 13, Number of Points: 343
Order: 14, Number of Points: 512
Order: 15, Number of Points: 512
Order: 16, Number of Points: 729
Order: 17, Number of Points: 729
Order: 18, Number of Points: 1000
Order: 19, Number of Points: 1000
Order: 20, Number of Points: 1331
The 2nd order has much more points even than 5th order. I saw it use preexisting solution instead of enumerating the 1D solution (https://gitlab.onelab.info/gmsh/gmsh/-/blob/master/Numeric/GaussQuadratureHex.cpp#L90). Is there anything I am missing? Thank you!