mirror of
https://github.com/JuliaFEM/JuliaFEM.jl.git
synced 2026-09-17 17:22:10 +00:00
Jukka Aho
53 lines
1.5 KiB
Julia
53 lines
1.5 KiB
Julia
# This file is a part of JuliaFEM.
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# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
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"""
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Calculate field values to nodal points from Gauss points using least-squares fitting.
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"""
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function calc_nodal_values!(elements, field_name, field_dim, time)
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A = SparseMatrixCOO()
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b = SparseMatrixCOO()
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for element in elements
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gdofs = get_connectivity(element)
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for ip in get_integration_points(element)
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detJ = element(ip, time, Val{:detJ})
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w = ip.weight*detJ
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f = ip(field_name, time)
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N = element(ip, time)
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add!(A, gdofs, gdofs, w*kron(N', N))
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for dim=1:field_dim
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add!(b, gdofs, w*f[dim]*N, dim)
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end
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end
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end
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A = sparse(A)
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b = sparse(b)
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nz = get_nonzero_rows(A)
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x = zeros(size(b)...)
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x[nz, :] = A[nz,nz] \ b[nz, :]
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nodal_values = Dict()
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for i=1:size(x,1)
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nodal_values[i] = vec(x[i,:])
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end
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update!(elements, field_name, nodal_values)
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end
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"""
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Return node ids + vector of values
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"""
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function get_nodal_vector(elements, field_name, time)
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f = Dict{Int64, Vector{Float64}}()
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for element in elements
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for (c, v) in zip(get_connectivity(element), element[field_name](time))
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if haskey(f, c)
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@assert isapprox(f[c], v)
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end
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f[c] = v
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end
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end
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node_ids = sort(collect(keys(f)))
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field = [f[nid] for nid in node_ids]
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return node_ids, field
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end
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