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use fenris::space::FixedInterpolator;
use nalgebra::{DVector, Vector2};
use proptest::prelude::*;
use matrixcompare::assert_scalar_eq;
#[test]
fn interpolate_into() {
let node_values = vec![1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0];
let node_indices = vec![
0, 1, // Interpolation point 1
0, 3, 4, // Interpolation point 2
1, 2, 4, // Interpolation point 3
]; // Interpolation point 4
let supported_node_offsets = vec![0, 2, 5, 8, 8];
// TODO: Test gradients... (They're implicitly tested in other proptests though)
let interpolator =
FixedInterpolator::from_compressed_values(Some(node_values), None, node_indices, supported_node_offsets);
let u = DVector::from_column_slice(&[1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0]);
let mut interpolated_values = vec![Vector2::zeros(); 4];
interpolator.interpolate_into(&mut interpolated_values, &u);
let v = interpolated_values;
assert_scalar_eq!(v[0].x, 7.0);
assert_scalar_eq!(v[0].y, 10.0);
assert_scalar_eq!(v[1].x, 76.0);
assert_scalar_eq!(v[1].y, 88.0);
assert_scalar_eq!(v[2].x, 125.0);
assert_scalar_eq!(v[2].y, 146.0);
assert_scalar_eq!(v[3].x, 0.0);
assert_scalar_eq!(v[3].y, 0.0);
}
// TODO: Use this in rewritten tests?
// fn find_interior_point<T>(polygon: &ConvexPolygon<T>) -> Point2<T>
// where
// T: Real,
// {
// // Find an interior point by averaging all vertices (note: this is not in general the centroid)
// let num_vertices = polygon.vertices().len();
// let vertex_sum = polygon
// .vertices()
// .iter()
// .map(|p| p.coords)
// .fold(Vector2::zeros(), |a, b| a + b);
// Point2::from(vertex_sum / T::from_usize(num_vertices).unwrap())
// }
proptest! {
// TODO: Rewrite this test without NodalModel/Quad4Model
// #[test]
// fn finite_element_interpolator_is_identity_for_node_vertices(
// mesh in rectangular_uniform_mesh_strategy(1.0, 8))
// {
// prop_assume!(mesh.connectivity().len() > 0);
//
// let quadrature = quad_quadrature_strength_5_f64();
// let model = Quad4Model::from_mesh_and_quadrature(mesh.clone(), quadrature);
// let interpolation_vertices = mesh.vertices();
// let interpolator = model.make_interpolator(interpolation_vertices).unwrap();
//
// // Assume that the solution variable is x, with x corresponding to the position
// // of vertices. So x_h(X) = sum_i N_i(X) x_i, where x_h(X) is the deformed
// // position at reference position X. Then, clearly, if x_i == X_i, with X_i
// // being a node in the Lagrange finite element basis, then
// // x_h(X_i) == X_i.
// let vertices: Vec<_> = mesh.vertices()
// .iter()
// .map(|x| x.coords)
// .collect();
//
// let solution_variables = flatten_vertically(&vertices).unwrap();
// let mut result = vec![Vector2::zeros(); interpolation_vertices.len()];
//
// interpolator.interpolate_into(&mut result, &solution_variables);
//
// assert_eq!(result.len(), interpolation_vertices.len());
// for (v_result, v_expected) in result.iter().zip(interpolation_vertices) {
// // TODO: Use matrixcompare
// let diff = v_result - v_expected.coords;
// prop_assert!(diff.norm() <= 1e-6);
// }
// }
// TODO: Rewrite this test without NodalModel/Quad4Model
// #[test]
// fn finite_element_interpolation_at_interior_points_is_bounded_by_nodal_values(
// (mesh, u) in rectangular_uniform_mesh_strategy(1.0, 8).prop_flat_map(|mesh| {
// let ndof = mesh.vertices().len();
// let u_strategy = vec(-10.0..10.0, ndof).prop_map(move |v| DVector::from_iterator(ndof, v));
// (Just(mesh), u_strategy)
// }))
// {
// assert_eq!(mesh.vertices().len(), u.len());
// prop_assume!(mesh.connectivity().len() > 0);
//
// // It is easy to show that |u_h(x)| = |sum_i N_i(x) u_i| <= max_i |u_i|,
// // where u_i are the nodal values of the nodes for which x is in the support of the
// // nodal basis function.
//
// let quadrature = quad_quadrature_strength_5_f64();
// let model = Quad4Model::from_mesh_and_quadrature(mesh.clone(), quadrature);
//
// let interpolation_vertices: Vec<_> = mesh.connectivity().iter()
// .map(|connectivity| connectivity.cell(mesh.vertices()).unwrap())
// .map(|cell| ConvexPolygon::try_from(cell).expect("Meshes should only have convex cells"))
// .map(|polygon| find_interior_point(&polygon))
// .collect();
//
// let interpolator = model.make_interpolator(&interpolation_vertices).unwrap();
// let mut result = vec![OVector::<f64, U1>::zeros(); interpolation_vertices.len()];
//
// interpolator.interpolate_into(&mut result, &u);
//
// prop_assert_eq!(result.len(), interpolation_vertices.len());
//
// for (i, u_result) in result.iter().map(|p| p[0]).enumerate() {
// let cell_connectivity = mesh.connectivity()[i];
// let smaller_than_neighbor_nodes = cell_connectivity.vertex_indices()
// .iter()
// .map(|idx| u[*idx])
// .any(|u_j| u_result.abs() <= u_j.abs());
// prop_assert!(smaller_than_neighbor_nodes);
// }
// }
}