calculate stress, interpolate stress to nodes using lsq fitting

src/utils.jl

@@ -1,57 +1,6 @@
 # This file is a part of JuliaFEM.
 # License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
 
-""" Calculate nodal vector from set of elements.
-
-For example element 1 with dofs [1, 2, 3, 4] has [1, 1, 1, 1] and
-element 2 with dofs [3, 4, 5, 6] has [2, 2, 2, 2] the result will
-be sparse matrix with values [1, 1, 3, 3, 2, 2].
-
-Parameters
-----------
-field_name
-    name of field, e.g. "geometry"
-field_dim
-    degrees of freedom / node
-elements
-    elements used to calculate vector
-vec_dim
-    used to resize solution vector if given
-time
-"""
-function calculate_nodal_vector(field_name, field_dim, elements::Vector{Element},
-                                time, vec_dim=0)
-    A = SparseMatrixCOO()
-    b = SparseMatrixCOO()
-    for element in elements
-        haskey(element, field_name) || continue
-        gdofs = get_gdofs(element, 1)
-        for ip in get_integration_points(element, Val{3})
-            J = get_jacobian(element, ip, time)
-            w = ip.weight*norm(J)
-            f = element(field_name, ip, 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)
-            end
-        end
-    end
-    A = sparse(A)
-    b = sparse(b)
-    nz = sort(unique(rowvals(A)))
-    x = zeros(size(b)...)
-    x[nz, :] = A[nz,nz] \ b[nz, :]
-    x = vec(transpose(x))
-    if vec_dim != 0
-        v = zeros(vec_dim)
-        v[1:length(x)] = x
-        return v
-    else
-        return x
-    end
-end
-
 function calculate_rotated_nodal_vector(field_name, field_dim, elements::Vector{Element},
                                         time, vec_dim=0)
     A = SparseMatrixCOO()