code refactoring

src/postprocess_utils.jl

@@ -1,42 +1,77 @@
 # This file is a part of JuliaFEM.
 # License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
 
+using JuliaFEM
+
 """
 Calculate field values to nodal points from Gauss points using least-squares fitting.
 """
-function calc_nodal_values!(elements, field_name, field_dim, time)
-    A = SparseMatrixCOO()
-    b = SparseMatrixCOO()
-    for element in elements
-        gdofs = get_connectivity(element)
-        for ip in get_integration_points(element)
-            detJ = element(ip, time, Val{:detJ})
-            w = ip.weight*detJ
-            f = ip(field_name, time)
-            N = element(ip, time)
-            add!(A, gdofs, gdofs, w*kron(N', N))
-            for dim=1:field_dim
-                add!(b, gdofs, w*f[dim]*N, dim)
+function calc_nodal_values!(elements::Vector, field_name, field_dim, time;
+                            F=nothing, nz=nothing, b=nothing, return_F_and_nz=false)
+
+    if F == nothing
+        A = SparseMatrixCOO()
+        for element in elements
+            gdofs = get_connectivity(element)
+            for ip in get_integration_points(element)
+                detJ = element(ip, time, Val{:detJ})
+                w = ip.weight*detJ
+                N = element(ip, time)
+                add!(A, gdofs, gdofs, w*kron(N', N))
             end
         end
+        nz = get_nonzero_rows(A)
+        A = sparse(A)
+        A = 1/2*(A + A')
+        F = ldltfact(A[nz,nz])
     end
-    A = sparse(A)
-    b = sparse(b)
-    nz = get_nonzero_rows(A)
+
+    if b == nothing
+        b = SparseMatrixCOO()
+        for element in elements
+            gdofs = get_connectivity(element)
+            for ip in get_integration_points(element)
+                if !haskey(ip, field_name)
+                    info("warning: integration point does not have field $field_name")
+                    continue
+                end
+                detJ = element(ip, time, Val{:detJ})
+                w = ip.weight*detJ
+                f = ip(field_name, time)
+                N = element(ip, time)
+                for dim=1:field_dim
+                    add!(b, gdofs, w*f[dim]*N, dim)
+                end
+            end
+        end
+        b = sparse(b)
+    end
+
     x = zeros(size(b)...)
-    x[nz, :] = A[nz,nz] \ b[nz, :]
+    x[nz, :] = F \ b[nz, :]
     nodal_values = Dict()
     for i=1:size(x,1)
         nodal_values[i] = vec(x[i,:])
     end
-    update!(elements, field_name, nodal_values)
+    update!(elements, field_name, time => nodal_values)
+    if return_F_and_nz
+        return F, nz
+    end
+end
+
+function calc_nodal_values!(problem::Problem, field_name, field_dim, time)
+    # after all, it's just a mass matrix ...
+#   isempty(problem.assembly.M) && assemble!(problem, time, Val{:mass_matrix}; density=1.0, dual_basis=false, dim=1)
+#   M = sparse(problem.assembly.M)
+    # TODO: make test before implementation
+    calc_nodal_values!(problem.elements, field_name, field_dim, time)
 end
 
 """
 Return node ids + vector of values 
 """
 function get_nodal_vector(elements, field_name, time)
-    f = Dict{Int64, Vector{Float64}}()
+    f = Dict()
     for element in elements
         for (c, v) in zip(get_connectivity(element), element[field_name](time))
             if haskey(f, c)
@@ -50,3 +85,32 @@ function get_nodal_vector(elements, field_name, time)
     return node_ids, field
 end
 
+""" Update nodal field values from set of elements to another. Can be used to
+transform e.g. reaction force from boundary element set to surface of
+volume elements for easier postprocess.
+"""
+function copy_field!(src_elements::Vector, dst_elements::Vector, field_name, time)
+    dst_nodes = Set{Int64}()
+    for element in dst_elements
+        push!(dst_nodes, get_connectivity(element)...)
+    end
+    node_ids, field = get_nodal_vector(src_elements, field_name, time)
+    z = 0.0*first(field)
+    d = Dict()
+    for j in dst_nodes
+        d[j] = z
+    end
+    for (j, f) in zip(node_ids, field)
+        d[j] = f
+    end
+    for element in dst_elements
+        c = get_connectivity(element)
+        f = [d[j] for j in c]
+        update!(element, field_name, time => f)
+    end
+end
+
+function copy_field!(src_problem::Problem, dst_problem::Problem, field_name, time)
+    copy_field!(src_problem.elements, dst_problem.elements, field_name, time)
+end
+