tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it./opt/beamfd/src/solver.cpp
1 #include "beamfd/solver.hpp"
2
3 #include <cmath>
4 #include <cstddef>
5 #include <stdexcept>
6 #include <vector>
7
8 #include "beamfd/linalg.hpp"
9 #include "beamfd/types.hpp"
10
11 namespace beamfd {
12
13 // ============================================================================
14 // TODO(candidate): Implement the beam-bending finite-difference core.
15 //
16 // Two member functions below are stubs that currently return a zero deflection
17 // field and an empty/zero system, so every analysis is wrong and the grader
18 // fails. Replace the stub bodies of
19 //
20 // BeamSystem BeamSolver::assemble_system() const;
21 // BeamResult BeamSolver::solve() const;
22 //
23 // with correct implementations of the boundary-value problem specified in
24 // instruction.md. Do NOT change the public signatures declared in
25 // include/beamfd/solver.hpp, do NOT modify the recovery helpers below, and
26 // reuse the existing support layer (DenseMatrix, solve_general, and the Beam
27 // accessors EI_at / k_at / q_at / end_moment / applied_end_shear / left /
28 // right / dx / num_intervals / num_nodes / validate).
29 //
30 // The physics, the support and load semantics, the contract, and the I/O
31 // format are described in instruction.md. The required behaviour is enforced
32 // by a hidden grading suite (the shipped tests/ are only a smoke check); design
33 // a discretization that is at least second-order accurate and assemble the
34 // linear system A w = b for the nodal deflection, then solve it with
35 // solve_general. Call Beam::validate() at the start of solve() and let its
36 // exceptions (and any singular-system exception from solve_general) propagate.
37 // ============================================================================
38
39 BeamSystem BeamSolver::assemble_system() const {
40 // TODO(candidate): build and return the finite-difference system A w = b.
41 const std::size_t n = beam_.num_nodes();
42 BeamSystem sys;
43 sys.A = DenseMatrix(n, n); // all zeros -> singular / wrong
44 sys.b.assign(n, 0.0);
45 return sys;
46 }
47
48 BeamResult BeamSolver::solve() const {
49 // TODO(candidate): validate, assemble, solve, return the deflection field.
50 const std::size_t n = beam_.num_nodes();
51 BeamResult result;
52 result.deflection.assign(n, 0.0); // trivially zero -> wrong
53 return result;
54 }
55
56 // ----------------------------------------------------------------------------
57 // Recovery helpers (already implemented; do NOT modify). These differentiate a
58 // given deflection field so callers can recompute physical quantities (bending
59 // moment, shear) directly from a candidate result, honoring a variable EI(x).
60
61 namespace {
62
63 // Second derivative w''(x_i) by central difference (interior) / one-sided
64 // 2nd-order difference (ends).
65 double second_derivative(const std::vector<double>& w, std::size_t i, double h2) {
66 const std::size_t n = w.size();
67 if (i == 0) {
68 return (2.0 * w[0] - 5.0 * w[1] + 4.0 * w[2] - w[3]) / h2;
69 }
70 if (i == n - 1) {
71 return (2.0 * w[n - 1] - 5.0 * w[n - 2] + 4.0 * w[n - 3] - w[n - 4]) / h2;
72 }
73 return (w[i - 1] - 2.0 * w[i] + w[i + 1]) / h2;
74 }
75
76 } // namespace
77
78 std::vector<double> BeamSolver::bending_moment_field(
79 const std::vector<double>& w) const {
80 const std::size_t n = beam_.num_nodes();
81 if (w.size() != n) {
82 throw std::invalid_argument("bending_moment_field: deflection size mismatch");
83 }
84 const double h2 = beam_.dx() * beam_.dx();
85 std::vector<double> M(n, 0.0);
86 for (std::size_t i = 0; i < n; ++i) {
87 M[i] = beam_.EI_at(i) * second_derivative(w, i, h2);
88 }
89 return M;
90 }
91
92 std::vector<double> BeamSolver::shear_field(const std::vector<double>& w) const {
93 const std::size_t n = beam_.num_nodes();
94 if (w.size() != n) {
95 throw std::invalid_argument("shear_field: deflection size mismatch");
96 }
97 if (n < 5) {
98 throw std::invalid_argument("shear_field: need at least 5 nodes");
99 }
100 const double h = beam_.dx();
101 const double h2 = h * h;
102 std::vector<double> m(n, 0.0);
103 for (std::size_t j = 0; j < n; ++j) {
104 m[j] = beam_.EI_at(j) * second_derivative(w, j, h2);
105 }
106 std::vector<double> V(n, 0.0);
107 for (std::size_t i = 0; i < n; ++i) {
108 if (i == 0) {
109 V[i] = (-3.0 * m[0] + 4.0 * m[1] - m[2]) / (2.0 * h);
110 } else if (i == n - 1) {
111 V[i] = (3.0 * m[n - 1] - 4.0 * m[n - 2] + m[n - 3]) / (2.0 * h);
112 } else {
113 V[i] = (m[i + 1] - m[i - 1]) / (2.0 * h);
114 }
115 }
116 return V;
117 }
118
119 } // namespace beamfd
120
/opt/beamfd/include/beamfd/solver.hpp
1 #ifndef BEAMFD_SOLVER_HPP
2 #define BEAMFD_SOLVER_HPP
3
4 #include <cstddef>
5 #include <vector>
6
7 #include "beamfd/beam.hpp"
8 #include "beamfd/linalg.hpp"
9
10 namespace beamfd {
11
12 /// The assembled finite-difference linear system A w = b for a beam.
13 /// `A` has size num_nodes x num_nodes and `b` has length num_nodes; the
14 /// unknown w is the nodal transverse deflection field. Exposed so tests can
15 /// check the discrete equilibrium residual directly.
16 struct BeamSystem {
17 DenseMatrix A;
18 std::vector<double> b;
19 };
20
21 /// Result of a static beam-bending analysis.
22 struct BeamResult {
23 /// Nodal transverse deflection w_i [m], length == beam.num_nodes(),
24 /// ordered from x = 0 (i = 0) to x = L (i = num_intervals).
25 std::vector<double> deflection;
26 };
27
28 /// Static bending solver for an Euler-Bernoulli beam with (possibly) variable
29 /// flexural rigidity and an optional elastic foundation. The continuum
30 /// boundary-value problem and the support/load semantics are specified in
31 /// instruction.md; choosing and assembling a suitable finite-difference
32 /// discretization of it, and solving the resulting linear system, is the work
33 /// of this class.
34 class BeamSolver {
35 public:
36 explicit BeamSolver(const Beam& beam) : beam_(beam) {}
37
38 /// Run the full analysis. Calls Beam::validate() first and propagates any
39 /// exception it throws. Throws std::runtime_error if the assembled system
40 /// is singular.
41 BeamResult solve() const;
42
43 /// Assemble the finite-difference system A w = b. Exposed for testing and
44 /// reuse (the discrete equilibrium-residual invariant checks A w - b ~ 0 at
45 /// the interior nodes).
46 BeamSystem assemble_system() const;
47
48 // ---- Recovery helpers (fully implemented; operate on a deflection field).
49 // These let the caller recompute physical quantities directly from a
50 // candidate deflection vector, independent of how it was produced.
51
52 /// Bending moment M_i = EI(x_i) * w''(x_i) [N*m] via a central second
53 /// difference at interior nodes and a one-sided second difference at the
54 /// ends. `w` must have length num_nodes(). Throws std::invalid_argument
55 /// otherwise.
56 std::vector<double> bending_moment_field(const std::vector<double>& w) const;
57
58 /// Shear force V_i = (EI w'')'(x_i) [N] via finite differences of the
59 /// nodal bending moment. `w` must have length num_nodes(). Throws
60 /// std::invalid_argument otherwise.
61 std::vector<double> shear_field(const std::vector<double>& w) const;
62
63 private:
64 const Beam& beam_;
65 };
66
67 } // namespace beamfd
68
69 #endif // BEAMFD_SOLVER_HPP
70
/opt/beamfd/include/beamfd/beam.hpp
1 #ifndef BEAMFD_BEAM_HPP
2 #define BEAMFD_BEAM_HPP
3
4 #include <cstddef>
5 #include <utility>
6 #include <vector>
7
8 #include "beamfd/types.hpp"
9
10 namespace beamfd {
11
12 /// A 1D Euler-Bernoulli beam discretized on a uniform grid, with a possibly
13 /// non-uniform flexural rigidity EI(x), an optional Winkler elastic foundation
14 /// k(x), a (possibly spatially varying) transverse load q(x), and optional
15 /// applied force/moment at free ends.
16 ///
17 /// This is a plain data container plus light validation. The numerical core
18 /// (assembling and solving the finite-difference system for the deflection
19 /// field) lives in BeamSolver (see solver.hpp).
20 ///
21 /// Geometry / grid:
22 /// - The beam occupies x in [0, L], divided into `num_intervals` equal cells,
23 /// giving num_nodes() = num_intervals + 1 grid points at x_i = i * dx,
24 /// dx = L / num_intervals, for i = 0 .. num_intervals.
25 ///
26 /// Fields are stored per node (length num_nodes()):
27 /// - EI_at(i) flexural rigidity at node i [N*m^2] (> 0)
28 /// - k_at(i) Winkler foundation modulus at node i [N/m^2] (>= 0; 0 = none)
29 /// - q_at(i) distributed transverse load at node i [N/m]
30 /// plus optional applied actions at free ends (force [N] and moment [N*m]).
31 class Beam {
32 public:
33 /// Construct a beam of length `length` [m] with a uniform flexural rigidity
34 /// `EI` [N*m^2], discretized into `num_intervals` equal cells, with the
35 /// given end supports. EI(x) is initialised constant, k(x) = 0, q(x) = 0.
36 /// Throws std::invalid_argument if length or EI is non-positive or
37 /// num_intervals < 2.
38 Beam(double length, double EI, std::size_t num_intervals, Support left,
39 Support right);
40
41 // ---- Field setters -------------------------------------------------------
42
43 /// Set the nodal flexural-rigidity field EI(x_i). Size must equal
44 /// num_nodes(); every value must be > 0. Throws std::invalid_argument.
45 void set_ei_nodal(const std::vector<double>& ei);
46
47 /// Set EI(x) from piecewise-linear control points (x, value), sampled at
48 /// each node. Points are taken in the given order; x outside the range is
49 /// clamped to the nearest endpoint value. Every sampled value must be > 0.
50 void set_ei_profile(const std::vector<std::pair<double, double>>& points);
51
52 /// Set the nodal Winkler foundation field k(x_i) >= 0. Size == num_nodes().
53 void set_foundation_nodal(const std::vector<double>& k);
54
55 /// Set k(x) from piecewise-linear control points (x, value).
56 void set_foundation_profile(
57 const std::vector<std::pair<double, double>>& points);
58
59 /// Set the nodal distributed-load field q(x_i). Size == num_nodes().
60 void set_q_nodal(const std::vector<double>& q);
61
62 /// Set a uniform distributed load q [N/m] over the whole span (overwrites
63 /// the load field).
64 void set_distributed_load(double q);
65
66 /// Add a piecewise-linear distributed-load segment ramping from q0 at x0 to
67 /// q1 at x1 [N/m] to the existing load field. Segments are additive.
68 void add_load_segment(double x0, double x1, double q0, double q1);
69
70 /// Apply a transverse force P [N] at a free end (`at_left_end` -> x = 0,
71 /// else x = L). Throws std::runtime_error if that end is not Free.
72 void set_end_load(double P, bool at_left_end);
73
74 /// Apply a concentrated moment M [N*m] at a free end. Throws
75 /// std::runtime_error if that end is not Free.
76 void set_end_moment(double M, bool at_left_end);
77
78 // ---- Accessors -----------------------------------------------------------
79
80 double length() const { return length_; }
81 std::size_t num_intervals() const { return num_intervals_; }
82 std::size_t num_nodes() const { return num_intervals_ + 1; }
83 double dx() const { return length_ / static_cast<double>(num_intervals_); }
84 double node_x(std::size_t i) const;
85
86 Support left() const { return left_; }
87 Support right() const { return right_; }
88
89 double EI_at(std::size_t i) const; ///< nodal flexural rigidity [N*m^2]
90 double k_at(std::size_t i) const; ///< nodal foundation modulus [N/m^2]
91 double q_at(std::size_t i) const; ///< nodal distributed load [N/m]
92
93 /// A representative (maximum nodal) flexural rigidity [N*m^2], used as a
94 /// scale for residual normalisation. Equals the constant EI for a uniform
95 /// beam.
96 double EI() const;
97
98 /// True if any nodal foundation modulus is strictly positive.
99 bool has_foundation() const;
100
101 /// Applied end shear V at a free end (`left_end` -> x = 0). A transverse
102 /// force P at a free end contributes V = -P; 0 if no force is applied.
103 double applied_end_shear(bool left_end) const;
104
105 /// Applied end moment M [N*m] at a free end (0 if none).
106 double end_moment(bool left_end) const;
107
108 /// True if any end force has been applied.
109 bool has_end_load() const;
110
111 /// Throws std::runtime_error if the support / foundation combination cannot
112 /// suppress rigid-body motion (a free end opposite a non-clamped end, or
113 /// two free ends, is a mechanism UNLESS an elastic foundation is present).
114 void validate() const;
115
116 private:
117 static std::size_t end_index(bool left_end) { return left_end ? 0u : 1u; }
118
119 double length_{0.0};
120 std::size_t num_intervals_{0};
121 Support left_{Support::Clamped};
122 Support right_{Support::Free};
123 std::vector<double> ei_; // nodal EI, length num_nodes()
124 std::vector<double> k_; // nodal foundation, length num_nodes()
125 std::vector<double> q_; // nodal load, length num_nodes()
126 double force_[2]{0.0, 0.0}; // applied transverse force [left, right]
127 double moment_[2]{0.0, 0.0}; // applied moment [left, right]
128 };
129
130 } // namespace beamfd
131
132 #endif // BEAMFD_BEAM_HPP
133
/opt/beamfd/include/beamfd/linalg.hpp
1 #ifndef BEAMFD_LINALG_HPP
2 #define BEAMFD_LINALG_HPP
3
4 #include <cstddef>
5 #include <stdexcept>
6 #include <vector>
7
8 namespace beamfd {
9
10 /// A small, row-major dense matrix of doubles.
11 ///
12 /// Part of the engine's linear-algebra support layer; fully implemented. The
13 /// beam solver uses it to hold the finite-difference system matrix A in
14 /// A w = b. Unlike a structural stiffness matrix, A here is generally NON
15 /// symmetric (boundary-condition rows are one-sided difference stencils), so
16 /// the solve uses a general LU factorization rather than a Cholesky/LDL^T.
17 class DenseMatrix {
18 public:
19 DenseMatrix() = default;
20
21 DenseMatrix(std::size_t rows, std::size_t cols)
22 : rows_(rows), cols_(cols), data_(rows * cols, 0.0) {}
23
24 std::size_t rows() const { return rows_; }
25 std::size_t cols() const { return cols_; }
26
27 double& operator()(std::size_t r, std::size_t c) {
28 return data_[r * cols_ + c];
29 }
30 double operator()(std::size_t r, std::size_t c) const {
31 return data_[r * cols_ + c];
32 }
33
34 void fill(double v) {
35 for (auto& x : data_) x = v;
36 }
37
38 private:
39 std::size_t rows_{0};
40 std::size_t cols_{0};
41 std::vector<double> data_;
42 };
43
44 /// Solve the general (possibly non-symmetric) linear system A x = b by LU
45 /// factorization with partial (row) pivoting.
46 ///
47 /// `A` is the n-by-n system matrix and `b` is the right-hand side of length n.
48 /// Returns the solution vector x of length n.
49 ///
50 /// Throws std::runtime_error if A is not square, if the dimensions are
51 /// inconsistent, or if A is detected to be singular (a pivot column is
52 /// numerically zero), which is how an under-/over-determined boundary-value
53 /// problem surfaces.
54 std::vector<double> solve_general(const DenseMatrix& A,
55 const std::vector<double>& b);
56
57 } // namespace beamfd
58
59 #endif // BEAMFD_LINALG_HPP
60
/opt/beamfd/include/beamfd/types.hpp
1 #ifndef BEAMFD_TYPES_HPP
2 #define BEAMFD_TYPES_HPP
3
4 #include <cstddef>
5
6 namespace beamfd {
7
8 /// Type of support condition applied at one end of the beam.
9 ///
10 /// - Clamped (built-in / fixed): deflection and slope are both zero
11 /// (w = 0, w' = 0).
12 /// - Pinned (simple support): deflection is zero and the bending moment
13 /// is zero (w = 0, M = 0).
14 /// - Free: the bending moment and shear take their
15 /// applied values (M = M_applied, V = V_applied), both zero when no end
16 /// action is applied.
17 ///
18 /// See instruction.md for the continuum boundary-value problem these encode.
19 enum class Support {
20 Clamped,
21 Pinned,
22 Free,
23 };
24
25 } // namespace beamfd
26
27 #endif // BEAMFD_TYPES_HPP
28
ls -R /opt/beamfd --ignore=build 2>/dev/null | head -60
/opt/beamfd: CMakeLists.txt examples include src tests /opt/beamfd/examples: cantilever_tip.beam /opt/beamfd/include: beamfd /opt/beamfd/include/beamfd: beam.hpp io.hpp linalg.hpp solver.hpp types.hpp /opt/beamfd/src: beam.cpp io.cpp linalg.cpp main.cpp solver.cpp /opt/beamfd/tests: CMakeLists.txt test_smoke.cpp test_util.hpp [stdout] /opt/beamfd: CMakeLists.txt examples include src tests /opt/beamfd/examples: cantilever_tip.beam /opt/beamfd/include: beamfd /opt/beamfd/include/beamfd: beam.hpp io.hpp linalg.hpp solver.hpp types.hpp /opt/beamfd/src: beam.cpp io.cpp linalg.cpp main.cpp solver.cpp /opt/beamfd/tests: CMakeLists.txt test_smoke.cpp test_util.hpp
/opt/beamfd/src/beam.cpp
1 #include "beamfd/beam.hpp"
2
3 #include <algorithm>
4 #include <stdexcept>
5
6 namespace beamfd {
7
8 namespace {
9
10 // Piecewise-linear interpolation of control points (x, value) at coordinate x.
11 // Points are used in the given order (assumed nondecreasing in x); x outside
12 // the range is clamped to the nearest endpoint.
13 double interp(const std::vector<std::pair<double, double>>& pts, double x) {
14 if (pts.empty()) {
15 throw std::invalid_argument("Beam: empty profile control points");
16 }
17 if (x <= pts.front().first) return pts.front().second;
18 if (x >= pts.back().first) return pts.back().second;
19 for (std::size_t s = 1; s < pts.size(); ++s) {
20 const double x0 = pts[s - 1].first, x1 = pts[s].first;
21 if (x <= x1) {
22 const double t = (x1 > x0) ? (x - x0) / (x1 - x0) : 0.0;
23 return pts[s - 1].second + t * (pts[s].second - pts[s - 1].second);
24 }
25 }
26 return pts.back().second;
27 }
28
29 } // namespace
30
31 Beam::Beam(double length, double EI, std::size_t num_intervals, Support left,
32 Support right)
33 : length_(length),
34 num_intervals_(num_intervals),
35 left_(left),
36 right_(right) {
37 if (length_ <= 0.0) {
38 throw std::invalid_argument("Beam: length must be positive");
39 }
40 if (EI <= 0.0) {
41 throw std::invalid_argument("Beam: EI must be positive");
42 }
43 if (num_intervals_ < 2) {
44 throw std::invalid_argument("Beam: need at least 2 intervals");
45 }
46 const std::size_t n = num_nodes();
47 ei_.assign(n, EI);
48 k_.assign(n, 0.0);
49 q_.assign(n, 0.0);
50 }
51
52 void Beam::set_ei_nodal(const std::vector<double>& ei) {
53 if (ei.size() != num_nodes()) {
54 throw std::invalid_argument("Beam::set_ei_nodal: size mismatch");
55 }
56 for (double v : ei) {
57 if (v <= 0.0) {
58 throw std::invalid_argument("Beam::set_ei_nodal: EI must be positive");
59 }
60 }
61 ei_ = ei;
62 }
63
64 void Beam::set_ei_profile(const std::vector<std::pair<double, double>>& points) {
65 std::vector<double> ei(num_nodes());
66 for (std::size_t i = 0; i < num_nodes(); ++i) ei[i] = interp(points, node_x(i));
67 set_ei_nodal(ei);
68 }
69
70 void Beam::set_foundation_nodal(const std::vector<double>& k) {
71 if (k.size() != num_nodes()) {
72 throw std::invalid_argument("Beam::set_foundation_nodal: size mismatch");
73 }
74 for (double v : k) {
75 if (v < 0.0) {
76 throw std::invalid_argument(
77 "Beam::set_foundation_nodal: k must be non-negative");
78 }
79 }
80 k_ = k;
81 }
82
83 void Beam::set_foundation_profile(
84 const std::vector<std::pair<double, double>>& points) {
85 std::vector<double> k(num_nodes());
86 for (std::size_t i = 0; i < num_nodes(); ++i) k[i] = interp(points, node_x(i));
87 set_foundation_nodal(k);
88 }
89
90 void Beam::set_q_nodal(const std::vector<double>& q) {
91 if (q.size() != num_nodes()) {
92 throw std::invalid_argument("Beam::set_q_nodal: size mismatch");
93 }
94 q_ = q;
95 }
96
97 void Beam::set_distributed_load(double q) { q_.assign(num_nodes(), q); }
98
99 void Beam::add_load_segment(double x0, double x1, double q0, double q1) {
100 if (x1 < x0) {
101 std::swap(x0, x1);
102 std::swap(q0, q1);
103 }
104 for (std::size_t i = 0; i < num_nodes(); ++i) {
105 const double x = node_x(i);
106 if (x < x0 || x > x1) continue;
107 const double t = (x1 > x0) ? (x - x0) / (x1 - x0) : 0.0;
108 q_[i] += q0 + t * (q1 - q0);
109 }
110 }
111
112 void Beam::set_end_load(double P, bool at_left_end) {
113 const Support s = at_left_end ? left_ : right_;
114 if (s != Support::Free) {
115 throw std::runtime_error(
116 "Beam::set_end_load: end load may only be applied at a free end");
117 }
118 force_[end_index(at_left_end)] = P;
119 }
120
121 void Beam::set_end_moment(double M, bool at_left_end) {
122 const Support s = at_left_end ? left_ : right_;
123 if (s != Support::Free) {
124 throw std::runtime_error(
125 "Beam::set_end_moment: end moment may only be applied at a free end");
126 }
127 moment_[end_index(at_left_end)] = M;
128 }
129
130 double Beam::node_x(std::size_t i) const {
131 if (i > num_intervals_) {
132 throw std::out_of_range("Beam::node_x: node index out of range");
133 }
134 return static_cast<double>(i) * dx();
135 }
136
137 double Beam::EI_at(std::size_t i) const {
138 if (i >= ei_.size()) throw std::out_of_range("Beam::EI_at: index out of range");
139 return ei_[i];
140 }
141
142 double Beam::k_at(std::size_t i) const {
143 if (i >= k_.size()) throw std::out_of_range("Beam::k_at: index out of range");
144 return k_[i];
145 }
146
147 double Beam::q_at(std::size_t i) const {
148 if (i >= q_.size()) throw std::out_of_range("Beam::q_at: index out of range");
149 return q_[i];
150 }
151
152 double Beam::EI() const {
153 double m = 0.0;
154 for (double v : ei_) m = std::max(m, v);
155 return m;
156 }
157
158 bool Beam::has_foundation() const {
159 for (double v : k_) {
160 if (v > 0.0) return true;
161 }
162 return false;
163 }
164
165 double Beam::applied_end_shear(bool left_end) const {
166 return -force_[end_index(left_end)];
167 }
168
169 double Beam::end_moment(bool left_end) const { return moment_[end_index(left_end)]; }
170
171 bool Beam::has_end_load() const { return force_[0] != 0.0 || force_[1] != 0.0; }
172
173 void Beam::validate() const {
174 const bool left_free = (left_ == Support::Free);
175 const bool right_free = (right_ == Support::Free);
176
177 // An elastic foundation supplies distributed restraint that removes the
178 // rigid-body modes, so any support combination is well posed when present.
179 if (has_foundation()) return;
180
181 if (left_free && right_free) {
182 throw std::runtime_error("Beam::validate: free-free beam is a mechanism");
183 }
184 if (left_free && right_ != Support::Clamped) {
185 throw std::runtime_error(
186 "Beam::validate: a free end requires a clamped opposite end");
187 }
188 if (right_free && left_ != Support::Clamped) {
189 throw std::runtime_error(
190 "Beam::validate: a free end requires a clamped opposite end");
191 }
192 }
193
194 } // namespace beamfd
195
/opt/beamfd/tests/test_smoke.cpp
1 // Smoke test for the beamfd project: a minimal, non-leaky sanity check so the
2 // project compiles and a solver gets quick feedback. It asserts only generic
3 // properties (finite field, pinned ends fixed, a non-trivial deflection, and a
4 // small interior discrete-equilibrium residual) and contains NO closed-form
5 // answer. The authoritative grading is performed by a separate hidden suite.
6
7 #include <algorithm>
8 #include <cmath>
9
10 #include "beamfd/beam.hpp"
11 #include "beamfd/solver.hpp"
12 #include "test_util.hpp"
13
14 using namespace beamfd;
15
16 BEAMFD_TEST("smoke_pinned_udl_sane") {
17 Beam beam(2.0, 1000.0, 20, Support::Pinned, Support::Pinned);
18 beam.set_distributed_load(5.0);
19 BeamSolver solver(beam);
20 BeamResult r = solver.solve();
21 const std::size_t n = beam.num_nodes();
22
23 beamfd_test::expect(r.deflection.size() == n, "deflection has num_nodes entries");
24 for (double w : r.deflection) {
25 beamfd_test::expect(std::isfinite(w), "deflection is finite");
26 }
27 beamfd_test::expect_near(r.deflection[0], 0.0, 1e-9, "left pin fixed");
28 beamfd_test::expect_near(r.deflection[n - 1], 0.0, 1e-9, "right pin fixed");
29 beamfd_test::expect(r.deflection[n / 2] > 0.0, "mid-span deflects under load");
30
31 // Interior discrete-equilibrium residual A w - b ~ 0 (relative to scale).
32 BeamSystem sys = solver.assemble_system();
33 double scale = 0.0;
34 for (double w : r.deflection) scale = std::max(scale, std::fabs(w));
35 const double c4 = beam.EI() / std::pow(beam.dx(), 4);
36 for (std::size_t i = 2; i + 2 < n; ++i) {
37 double res = -sys.b[i];
38 for (std::size_t j = 0; j < n; ++j) res += sys.A(i, j) * r.deflection[j];
39 beamfd_test::expect(std::fabs(res) <= 1e-6 * (c4 * scale) + 1e-9,
40 "interior equilibrium residual is small");
41 }
42 }
43
44 BEAMFD_TEST_MAIN()
45
/opt/beamfd/tests/test_util.hpp
1 #ifndef BEAMFD_TEST_UTIL_HPP
2 #define BEAMFD_TEST_UTIL_HPP
3
4 // Minimal dependency-free test harness for the beamfd suite.
5 //
6 // Each test executable defines test functions and registers them with
7 // BEAMFD_TEST(name) { ... }. main() (provided by BEAMFD_TEST_MAIN) runs every
8 // registered test and returns non-zero if any assertion fails, which CTest
9 // interprets as a failure.
10
11 #include <cmath>
12 #include <cstddef>
13 #include <functional>
14 #include <iostream>
15 #include <string>
16 #include <vector>
17
18 namespace beamfd_test {
19
20 struct Case {
21 std::string name;
22 std::function<void()> fn;
23 };
24
25 inline std::vector<Case>& registry() {
26 static std::vector<Case> cases;
27 return cases;
28 }
29
30 struct Registrar {
31 Registrar(const std::string& name, std::function<void()> fn) {
32 registry().push_back(Case{name, std::move(fn)});
33 }
34 };
35
36 // Thrown by an assertion failure to abort the current test case.
37 struct AssertionError {
38 std::string message;
39 };
40
41 inline void expect(bool cond, const std::string& what) {
42 if (!cond) {
43 throw AssertionError{what};
44 }
45 }
46
47 inline void expect_near(double got, double want, double tol, const std::string& what) {
48 if (std::fabs(got - want) > tol) {
49 throw AssertionError{what + " (got " + std::to_string(got) +
50 ", want " + std::to_string(want) +
51 ", tol " + std::to_string(tol) + ")"};
52 }
53 }
54
55 // Relative-error check (with an absolute floor) for quantities whose scale
56 // varies widely across cases.
57 inline void expect_rel(double got, double want, double rel_tol,
58 const std::string& what) {
59 const double denom = std::fabs(want) > 1e-300 ? std::fabs(want) : 1.0;
60 if (std::fabs(got - want) / denom > rel_tol) {
61 throw AssertionError{what + " (got " + std::to_string(got) +
62 ", want " + std::to_string(want) +
63 ", rel_tol " + std::to_string(rel_tol) + ")"};
64 }
65 }
66
67 inline int run_all() {
68 int failures = 0;
69 for (const auto& c : registry()) {
70 try {
71 c.fn();
72 std::cout << "[ PASS ] " << c.name << "\n";
73 } catch (const AssertionError& e) {
74 std::cout << "[ FAIL ] " << c.name << ": " << e.message << "\n";
75 ++failures;
76 } catch (const std::exception& e) {
77 std::cout << "[ FAIL ] " << c.name
78 << ": unexpected exception: " << e.what() << "\n";
79 ++failures;
80 } catch (...) {
81 std::cout << "[ FAIL ] " << c.name << ": unknown exception\n";
82 ++failures;
83 }
84 }
85 std::cout << "----\n"
86 << (registry().size() - failures) << "/" << registry().size()
87 << " tests passed\n";
88 return failures == 0 ? 0 : 1;
89 }
90
91 } // namespace beamfd_test
92
93 #define BEAMFD_CONCAT_INNER(a, b) a##b
94 #define BEAMFD_CONCAT(a, b) BEAMFD_CONCAT_INNER(a, b)
95
96 #define BEAMFD_TEST(NAME) \
97 static void BEAMFD_CONCAT(beamfd_test_fn_, __LINE__)(); \
98 static ::beamfd_test::Registrar BEAMFD_CONCAT(beamfd_test_reg_, \
99 __LINE__){ \
100 NAME, &BEAMFD_CONCAT(beamfd_test_fn_, __LINE__)}; \
101 static void BEAMFD_CONCAT(beamfd_test_fn_, __LINE__)()
102
103 #define BEAMFD_TEST_MAIN() \
104 int main() { return ::beamfd_test::run_all(); }
105
106 #endif // BEAMFD_TEST_UTIL_HPP
107
/opt/beamfd/src/linalg.cpp
1 #include "beamfd/linalg.hpp"
2
3 #include <cmath>
4
5 namespace beamfd {
6
7 std::vector<double> solve_general(const DenseMatrix& A,
8 const std::vector<double>& b) {
9 const std::size_t n = A.rows();
10 if (A.cols() != n) {
11 throw std::runtime_error("solve_general: matrix is not square");
12 }
13 if (b.size() != n) {
14 throw std::runtime_error("solve_general: right-hand side size mismatch");
15 }
16
17 // Work on mutable copies (Gaussian elimination with partial pivoting).
18 DenseMatrix M = A;
19 std::vector<double> x = b;
20
21 for (std::size_t col = 0; col < n; ++col) {
22 // Find the pivot row (largest magnitude in this column at/below the
23 // diagonal) for numerical stability.
24 std::size_t pivot = col;
25 double best = std::fabs(M(col, col));
26 for (std::size_t r = col + 1; r < n; ++r) {
27 const double v = std::fabs(M(r, col));
28 if (v > best) {
29 best = v;
30 pivot = r;
31 }
32 }
33 if (best <= 1e-300) {
34 throw std::runtime_error("solve_general: matrix is singular");
35 }
36
37 // Swap pivot row into place (in both M and the RHS).
38 if (pivot != col) {
39 for (std::size_t c = 0; c < n; ++c) {
40 std::swap(M(col, c), M(pivot, c));
41 }
42 std::swap(x[col], x[pivot]);
43 }
44
45 // Eliminate entries below the pivot.
46 const double diag = M(col, col);
47 for (std::size_t r = col + 1; r < n; ++r) {
48 const double factor = M(r, col) / diag;
49 if (factor == 0.0) continue;
50 M(r, col) = 0.0;
51 for (std::size_t c = col + 1; c < n; ++c) {
52 M(r, c) -= factor * M(col, c);
53 }
54 x[r] -= factor * x[col];
55 }
56 }
57
58 // Back substitution.
59 for (std::size_t ii = 0; ii < n; ++ii) {
60 const std::size_t i = n - 1 - ii;
61 double s = x[i];
62 for (std::size_t c = i + 1; c < n; ++c) {
63 s -= M(i, c) * x[c];
64 }
65 x[i] = s / M(i, i);
66 }
67
68 return x;
69 }
70
71 } // namespace beamfd
72
/opt/beamfd/examples/cantilever_tip.beam
1 # Cantilever beam with a downward point load at the free tip. 2 # Clamped (built-in) at x = 0, free at x = L. 3 length 3.0 # span [m] 4 ei 2.0e6 # flexural rigidity EI [N*m^2] 5 cells 200 # number of equal finite-difference intervals 6 7 # Left end clamped, right end free. 8 support clamped free 9 10 # Downward point load of 1 kN at the free right tip. 11 endload right 1000.0 12
/opt/beamfd/src/solver.cpp
BeamSystem BeamSolver::assemble_system() const {
// TODO(candidate): build and return the finite-difference system A w = b.
const std::size_t n = beam_.num_nodes();
BeamSystem sys;
sys.A = DenseMatrix(n, n); // all zeros -> singular / wrong
sys.b.assign(n, 0.0);
return sys;
}
BeamResult BeamSolver::solve() const {
// TODO(candidate): validate, assemble, solve, return the deflection field.
const std::size_t n = beam_.num_nodes();
BeamResult result;
result.deflection.assign(n, 0.0); // trivially zero -> wrong
return result;
}BeamSystem BeamSolver::assemble_system() const {
// Uniform grid x_i = i*dx, i = 0..N, with n = N+1 nodal unknowns w_i.
// We discretize the conservative Euler-Bernoulli equation
//
// d^2/dx^2 ( EI(x) w''(x) ) + k(x) w(x) = q(x)
//
// at the interior nodes i = 2..N-2 with a second-order, conservative
// five-point stencil (a central second difference of the nodal bending
// moment M_j = EI_j w''_j), and close the system with two boundary rows at
// each end. Essential conditions (w, w') use direct/one-sided differences;
// natural conditions (M = EI w'', V = (EI w'')') use one-sided differences
// of the nodal moment. Every stencil is second-order accurate in dx.
const std::size_t n = beam_.num_nodes();
const std::size_t N = beam_.num_intervals(); // n == N + 1
const double h = beam_.dx();
const double h2 = h * h;
const double h4 = h2 * h2;
BeamSystem sys;
sys.A = DenseMatrix(n, n);
sys.b.assign(n, 0.0);
DenseMatrix& A = sys.A;
std::vector<double>& b = sys.b;
// Add c * w''(x_j) into row r: a second-order central second difference at
// interior nodes, and a second-order one-sided second difference at the
// two ends (the same stencils the recovery helpers use).
auto add_d2 = [&](std::size_t r, std::size_t j, double c) {
const double f = c / h2;
if (j == 0) {
A(r, 0) += 2.0 * f;
A(r, 1) += -5.0 * f;
A(r, 2) += 4.0 * f;
A(r, 3) += -1.0 * f;
} else if (j == N) {
A(r, N) += 2.0 * f;
A(r, N - 1) += -5.0 * f;
A(r, N - 2) += 4.0 * f;
A(r, N - 3) += -1.0 * f;
} else {
A(r, j - 1) += f;
A(r, j) += -2.0 * f;
A(r, j + 1) += f;
}
};
// Add c * w'(x_j) into row r at an end node: a second-order one-sided first
// difference (forward at j = 0, backward at j = N).
auto add_d1_end = [&](std::size_t r, std::size_t j, double c) {
const double f = c / (2.0 * h);
if (j == 0) {
A(r, 0) += -3.0 * f;
A(r, 1) += 4.0 * f;
A(r, 2) += -1.0 * f;
} else { // j == N
A(r, N) += 3.0 * f;
A(r, N - 1) += -4.0 * f;
A(r, N - 2) += f;
}
};
// ---- Interior governing equation: (EI w'')'' + k w = q at i = 2..N-2 -----
// M''_i = [ M_{i-1} - 2 M_i + M_{i+1} ] / h^2 with M_j = EI_j w''_j and
// w''_j the central second difference, expanded into nodal w coefficients.
for (std::size_t i = 2; i + 2 <= N; ++i) {
const double eim = beam_.EI_at(i - 1);
const double ei0 = beam_.EI_at(i);
const double eip = beam_.EI_at(i + 1);
A(i, i - 2) += eim / h4;
A(i, i - 1) += -2.0 * (eim + ei0) / h4;
A(i, i) += (eim + 4.0 * ei0 + eip) / h4 + beam_.k_at(i);
A(i, i + 1) += -2.0 * (ei0 + eip) / h4;
A(i, i + 2) += eip / h4;
b[i] = beam_.q_at(i);
}
// ---- Left end: boundary rows 0 and 1 ------------------------------------
switch (beam_.left()) {
case Support::Clamped:
A(0, 0) += 1.0; // w = 0
add_d1_end(1, 0, 1.0); // w' = 0
break;
case Support::Pinned:
A(0, 0) += 1.0; // w = 0
add_d2(1, 0, 1.0); // EI w'' = 0 -> w'' = 0
break;
case Support::Free: {
// V_0 = (EI w'')'(0) = (-3 M_0 + 4 M_1 - M_2) / (2h) = V_applied.
add_d2(0, 0, -3.0 * beam_.EI_at(0) / (2.0 * h));
add_d2(0, 1, 4.0 * beam_.EI_at(1) / (2.0 * h));
add_d2(0, 2, -1.0 * beam_.EI_at(2) / (2.0 * h));
b[0] = beam_.applied_end_shear(true);
// M_0 = EI_0 w''_0 = M_applied.
add_d2(1, 0, beam_.EI_at(0));
b[1] = beam_.end_moment(true);
break;
}
}
// ---- Right end: boundary rows N-1 and N ---------------------------------
switch (beam_.right()) {
case Support::Clamped:
A(N, N) += 1.0; // w = 0
add_d1_end(N - 1, N, 1.0); // w' = 0
break;
case Support::Pinned:
A(N, N) += 1.0; // w = 0
add_d2(N - 1, N, 1.0); // EI w'' = 0 -> w'' = 0
break;
case Support::Free: {
// V_N = (EI w'')'(L) = (3 M_N - 4 M_{N-1} + M_{N-2}) / (2h) = V_app.
add_d2(N, N, 3.0 * beam_.EI_at(N) / (2.0 * h));
add_d2(N, N - 1, -4.0 * beam_.EI_at(N - 1) / (2.0 * h));
add_d2(N, N - 2, beam_.EI_at(N - 2) / (2.0 * h));
b[N] = beam_.applied_end_shear(false);
// M_N = EI_N w''_N = M_applied.
add_d2(N - 1, N, beam_.EI_at(N));
b[N - 1] = beam_.end_moment(false);
break;
}
}
return sys;
}
BeamResult BeamSolver::solve() const {
beam_.validate(); // propagate mechanism / configuration errors
BeamSystem sys = assemble_system();
BeamResult result;
result.deflection = solve_general(sys.A, sys.b); // propagates if singular
return result;
}cmake -S . -B build -DCMAKE_BUILD_TYPE=Release >/dev/null 2>&1 && cmake --build build --parallel 2>&1 | tail -5 && cd build && ctest --output-on-failure 2>&1 | tail -20
[ 77%] Building CXX object CMakeFiles/beamfd_cli.dir/src/main.cpp.o
[ 88%] Linking CXX executable beamfd_cli
[ 88%] Built target beamfd_cli
[100%] Linking CXX executable test_smoke
[100%] Built target test_smoke
Test project /opt/beamfd/build
Start 1: smoke
1/1 Test #1: smoke ............................ Passed 0.00 sec
100% tests passed, 0 tests failed out of 1
Total Test time (real) = 0.00 sec
[stdout]
[ 77%] Building CXX object CMakeFiles/beamfd_cli.dir/src/main.cpp.o
[ 88%] Linking CXX executable beamfd_cli
[ 88%] Built target beamfd_cli
[100%] Linking CXX executable test_smoke
[100%] Built target test_smoke
Test project /opt/beamfd/build
Start 1: smoke
1/1 Test #1: smoke ............................ Passed 0.00 sec
100% tests passed, 0 tests failed out of 1
Total Test time (real) = 0.00 secls /opt/beamfd/build/*.a /opt/beamfd/build/**/*.a 2>/dev/null; echo "---"; cat /opt/beamfd/CMakeLists.txt | head -40
/opt/beamfd/build/libbeamfd.a
---
cmake_minimum_required(VERSION 3.16)
project(beamfd LANGUAGES CXX)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
if(NOT CMAKE_BUILD_TYPE)
set(CMAKE_BUILD_TYPE Release)
endif()
add_compile_options(-Wall -Wextra)
# --- Core library -----------------------------------------------------------
add_library(beamfd
src/linalg.cpp
src/beam.cpp
src/solver.cpp
src/io.cpp
)
target_include_directories(beamfd PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
# --- Demo CLI ---------------------------------------------------------------
add_executable(beamfd_cli src/main.cpp)
target_link_libraries(beamfd_cli PRIVATE beamfd)
# --- Tests ------------------------------------------------------------------
enable_testing()
add_subdirectory(tests)
[stdout]
/opt/beamfd/build/libbeamfd.a
---
cmake_minimum_required(VERSION 3.16)
project(beamfd LANGUAGES CXX)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
if(NOT CMAKE_BUILD_TYPE)
set(CMAKE_BUILD_TYPE Release)
endif()
add_compile_options(-Wall -Wextra)
# --- Core library -----------------------------------------------------------
add_library(beamfd
src/linalg.cpp
src/beam.cpp
src/solver.cpp
src/io.cpp
)
target_include_directories(beamfd PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
# --- Demo CLI ---------------------------------------------------------------
add_executable(beamfd_cli src/main.cpp)
target_link_libraries(beamfd_cli PRIVATE beamfd)
# --- Tests ------------------------------------------------------------------
enable_testing()
add_subdirectory(tests)#include <cmath>
#include <cstdio>
#include <vector>
#include <functional>
#include "beamfd/beam.hpp"
#include "beamfd/solver.hpp"
using namespace beamfd;
static double max_err(const std::vector<double>& w, std::function<double(double)> exact,
double L, std::size_t N) {
double e = 0.0;
for (std::size_t i = 0; i <= N; ++i) {
double x = (double)i * L / (double)N;
e = std::max(e, std::fabs(w[i] - exact(x)));
}
return e;
}
// Report convergence order between two meshes.
static void order(const char* name, double e1, std::size_t N1, double e2, std::size_t N2) {
double p = std::log(e1 / e2) / std::log((double)N2 / (double)N1);
printf(" %-28s N=%-4zu err=%.3e N=%-4zu err=%.3e order=%.2f\n",
name, N1, e1, N2, e2, p);
}
// ---- Case 1: clamped-clamped, variable EI(x)=a+bx, foundation k(x)=c+dx,
// manufactured w(x)=x^2 (L-x)^2. q = (EI w'')'' + k w (analytic). --------
static void case_cc_varEI_found(std::size_t N, double& err) {
const double L = 2.0;
const double a = 1000.0, b = 300.0; // EI(x)=a+bx
const double c = 50.0, d = 20.0; // k(x)=c+dx
auto w_exact = [&](double x){ double t=x*(L-x); return t*t; };
auto q = [&](double x){
double g2 = 24.0*a - 24.0*b*L + 72.0*b*x; // (EI w'')''
double t=x*(L-x); double w=t*t;
return g2 + (c + d*x)*w;
};
Beam beam(L, a, N, Support::Clamped, Support::Clamped);
beam.set_ei_profile({{0.0,a},{L,a+b*L}});
beam.set_foundation_profile({{0.0,c},{L,c+d*L}});
std::vector<double> qn(N+1);
for (std::size_t i=0;i<=N;++i) qn[i]=q((double)i*L/(double)N);
beam.set_q_nodal(qn);
BeamSolver s(beam);
err = max_err(s.solve().deflection, w_exact, L, N);
}
// ---- Case 2: clamped(left)-free(right), variable EI, manufactured w=x^4 ------
static void case_cf_varEI(std::size_t N, double& err) {
const double L = 2.0;
const double a = 1000.0, b = 300.0;
auto w_exact = [&](double x){ return x*x*x*x; };
auto q = [&](double x){ return 24.0*a + 72.0*b*x; }; // (EI w'')'' , k=0
Beam beam(L, a, N, Support::Clamped, Support::Free);
beam.set_ei_profile({{0.0,a},{L,a+b*L}});
std::vector<double> qn(N+1);
for (std::size_t i=0;i<=N;++i) qn[i]=q((double)i*L/(double)N);
beam.set_q_nodal(qn);
// free-end natural BCs at x=L: M(L)=g(L), V(L)=g'(L)
// g=EI w''=(a+bx)*12x^2; g'=24a x+36 b x^2
double gL = (a+b*L)*12.0*L*L;
double gpL = 24.0*a*L + 36.0*b*L*L;
beam.set_end_moment(gL, /*left=*/false);
beam.set_end_load(-gpL, /*left=*/false); // applied_end_shear = -P = gpL
BeamSolver s(beam);
err = max_err(s.solve().deflection, w_exact, L, N);
}
// ---- Case 3: pinned-pinned uniform UDL, closed form -------------------------
static void case_pp_udl(std::size_t N, double& err) {
const double L = 3.0, EI = 2000.0, q0 = 7.0;
auto w_exact = [&](double x){ return q0/(24.0*EI)*(x*x*x*x - 2.0*L*x*x*x + L*L*L*x); };
Beam beam(L, EI, N, Support::Pinned, Support::Pinned);
beam.set_distributed_load(q0);
BeamSolver s(beam);
err = max_err(s.solve().deflection, w_exact, L, N);
}
// ---- Case 4: free-free on foundation, manufactured w=cos-ish polynomial ------
// Use w(x)=x^4-2Lx^3+... actually use generic poly; foundation makes it well posed.
static void case_ff_found(std::size_t N, double& err) {
const double L = 2.0;
const double EI = 1500.0; // constant
const double k0 = 800.0; // constant foundation
auto w_exact = [&](double x){ return std::cos(M_PI*x/L); }; // w'(0)=0,w'(L)=0
auto q = [&](double x){
double w = std::cos(M_PI*x/L);
double w4 = std::pow(M_PI/L,4.0)*std::cos(M_PI*x/L); // d4/dx4 cos = (pi/L)^4 cos
return EI*w4 + k0*w;
};
Beam beam(L, EI, N, Support::Free, Support::Free);
beam.set_foundation_nodal(std::vector<double>(N+1,k0));
std::vector<double> qn(N+1);
for (std::size_t i=0;i<=N;++i) qn[i]=q((double)i*L/(double)N);
beam.set_q_nodal(qn);
// free ends: M=EI w''; V=EI w''' . w''=-(pi/L)^2 cos ; w'''=(pi/L)^3 sin
auto wpp=[&](double x){ return -std::pow(M_PI/L,2.0)*std::cos(M_PI*x/L); };
auto wppp=[&](double x){ return std::pow(M_PI/L,3.0)*std::sin(M_PI*x/L); };
beam.set_end_moment(EI*wpp(0.0), true);
beam.set_end_load(-(EI*wppp(0.0)), true); // V(0)=EI w'''(0); applied_shear=-P
beam.set_end_moment(EI*wpp(L), false);
beam.set_end_load(-(EI*wppp(L)), false);
BeamSolver s(beam);
err = max_err(s.solve().deflection, w_exact, L, N);
}
int main() {
struct C { const char* name; void(*fn)(std::size_t,double&); };
C cases[] = {
{"clamped-clamped varEI+found", case_cc_varEI_found},
{"clamped-free varEI (w=x^4)", case_cf_varEI},
{"pinned-pinned UDL (exact)", case_pp_udl},
{"free-free on foundation", case_ff_found},
};
for (auto& c : cases) {
printf("%s:\n", c.name);
double e1,e2,e3;
c.fn(40,e1); c.fn(80,e2); c.fn(160,e3);
order("40->80", e1,40, e2,80);
order("80->160", e2,80, e3,160);
}
return 0;
}
cd /opt/beamfd && g++ -std=c++17 -O2 -Iinclude /tmp/verify.cpp build/libbeamfd.a -o /tmp/verify 2>&1 | head && /tmp/verify
clamped-clamped varEI+found: 40->80 N=40 err=9.606e-03 N=80 err=2.448e-03 order=1.97 80->160 N=80 err=2.448e-03 N=160 err=6.179e-04 order=1.99 clamped-free varEI (w=x^4): 40->80 N=40 err=6.438e+00 N=80 err=3.296e+00 order=0.97 80->160 N=80 err=3.296e+00 N=160 err=1.667e+00 order=0.98 pinned-pinned UDL (exact): 40->80 N=40 err=2.030e-05 N=80 err=5.076e-06 order=2.00 80->160 N=80 err=5.076e-06 N=160 err=1.269e-06 order=2.00 free-free on foundation: 40->80 N=40 err=3.136e+00 N=80 err=1.419e+00 order=1.14 80->160 N=80 err=1.419e+00 N=160 err=6.758e-01 order=1.07 [stdout] clamped-clamped varEI+found: 40->80 N=40 err=9.606e-03 N=80 err=2.448e-03 order=1.97 80->160 N=80 err=2.448e-03 N=160 err=6.179e-04 order=1.99 clamped-free varEI (w=x^4): 40->80 N=40 err=6.438e+00 N=80 err=3.296e+00 order=0.97 80->160 N=80 err=3.296e+00 N=160 err=1.667e+00 order=0.98 pinned-pinned UDL (exact): 40->80 N=40 err=2.030e-05 N=80 err=5.076e-06 order=2.00 80->160 N=80 err=5.076e-06 N=160 err=1.269e-06 order=2.00 free-free on foundation: 40->80 N=40 err=3.136e+00 N=80 err=1.419e+00 order=1.14 80->160 N=80 err=1.419e+00 N=160 err=6.758e-01 order=1.07
/opt/beamfd/src/solver.cpp
case Support::Free: {
// V_0 = (EI w'')'(0) = (-3 M_0 + 4 M_1 - M_2) / (2h) = V_applied.
add_d2(0, 0, -3.0 * beam_.EI_at(0) / (2.0 * h));
add_d2(0, 1, 4.0 * beam_.EI_at(1) / (2.0 * h));
add_d2(0, 2, -1.0 * beam_.EI_at(2) / (2.0 * h));
b[0] = beam_.applied_end_shear(true);
// M_0 = EI_0 w''_0 = M_applied.
add_d2(1, 0, beam_.EI_at(0));
b[1] = beam_.end_moment(true);
break;
} case Support::Free: {
// Free end: the bending moment is prescribed, M_0 = M_applied, and
// the shear M'(0) = V_applied. In the conservative form M_0 is the
// applied moment directly, so we enforce the governing equation at
// the two end nodes and close it with these natural conditions
// (second order). M''_j = (M_{j-1} - 2 M_j + M_{j+1}) / h^2 with
// M_1 = EI_1 w''_1, M_2 = EI_2 w''_2 (central).
const double Mapp = beam_.end_moment(true);
const double Vapp = beam_.applied_end_shear(true);
const double ei1 = beam_.EI_at(1);
const double ei2 = beam_.EI_at(2);
// Row 0: PDE at node 0 using M_0 = Mapp and the shear-derived ghost
// M_{-1} = M_1 - 2h Vapp, so M''_0 = (2 M_1 - 2 Mapp - 2h Vapp)/h^2.
A(0, 0) += 2.0 * ei1 / h4 + beam_.k_at(0);
A(0, 1) += -4.0 * ei1 / h4;
A(0, 2) += 2.0 * ei1 / h4;
b[0] = beam_.q_at(0) + 2.0 * Mapp / h2 + 2.0 * Vapp / h;
// Row 1: PDE at node 1 using the prescribed M_0 = Mapp.
A(1, 0) += -2.0 * ei1 / h4;
A(1, 1) += (4.0 * ei1 + ei2) / h4 + beam_.k_at(1);
A(1, 2) += (-2.0 * ei1 - 2.0 * ei2) / h4;
A(1, 3) += ei2 / h4;
b[1] = beam_.q_at(1) - Mapp / h2;
break;
}/opt/beamfd/src/solver.cpp
case Support::Free: {
// V_N = (EI w'')'(L) = (3 M_N - 4 M_{N-1} + M_{N-2}) / (2h) = V_app.
add_d2(N, N, 3.0 * beam_.EI_at(N) / (2.0 * h));
add_d2(N, N - 1, -4.0 * beam_.EI_at(N - 1) / (2.0 * h));
add_d2(N, N - 2, beam_.EI_at(N - 2) / (2.0 * h));
b[N] = beam_.applied_end_shear(false);
// M_N = EI_N w''_N = M_applied.
add_d2(N - 1, N, beam_.EI_at(N));
b[N - 1] = beam_.end_moment(false);
break;
} case Support::Free: {
// Mirror of the left free end. M_N = M_applied, M'(L) = V_applied,
// ghost M_{N+1} = M_{N-1} + 2h Vapp.
const double Mapp = beam_.end_moment(false);
const double Vapp = beam_.applied_end_shear(false);
const double eiN1 = beam_.EI_at(N - 1);
const double eiN2 = beam_.EI_at(N - 2);
// Row N: PDE at node N, M''_N = (2 M_{N-1} - 2 Mapp + 2h Vapp)/h^2.
A(N, N) += 2.0 * eiN1 / h4 + beam_.k_at(N);
A(N, N - 1) += -4.0 * eiN1 / h4;
A(N, N - 2) += 2.0 * eiN1 / h4;
b[N] = beam_.q_at(N) + 2.0 * Mapp / h2 - 2.0 * Vapp / h;
// Row N-1: PDE at node N-1 using the prescribed M_N = Mapp.
A(N - 1, N) += -2.0 * eiN1 / h4;
A(N - 1, N - 1) += (4.0 * eiN1 + eiN2) / h4 + beam_.k_at(N - 1);
A(N - 1, N - 2) += (-2.0 * eiN1 - 2.0 * eiN2) / h4;
A(N - 1, N - 3) += eiN2 / h4;
b[N - 1] = beam_.q_at(N - 1) - Mapp / h2;
break;
}cmake --build build --parallel 2>&1 | grep -E "error|warning|Built target beamfd" | head && g++ -std=c++17 -O2 -Iinclude /tmp/verify.cpp build/libbeamfd.a -o /tmp/verify 2>&1 | head && /tmp/verify
[ 55%] Built target beamfd [ 88%] Built target beamfd_cli clamped-clamped varEI+found: 40->80 N=40 err=9.606e-03 N=80 err=2.448e-03 order=1.97 80->160 N=80 err=2.448e-03 N=160 err=6.179e-04 order=1.99 clamped-free varEI (w=x^4): 40->80 N=40 err=1.254e-02 N=80 err=2.953e-03 order=2.09 80->160 N=80 err=2.953e-03 N=160 err=7.152e-04 order=2.05 pinned-pinned UDL (exact): 40->80 N=40 err=2.030e-05 N=80 err=5.076e-06 order=2.00 80->160 N=80 err=5.076e-06 N=160 err=1.269e-06 order=2.00 free-free on foundation: 40->80 N=40 err=7.015e-03 N=80 err=1.755e-03 order=2.00 80->160 N=80 err=1.755e-03 N=160 err=4.388e-04 order=2.00 [stdout] [ 55%] Built target beamfd [ 88%] Built target beamfd_cli clamped-clamped varEI+found: 40->80 N=40 err=9.606e-03 N=80 err=2.448e-03 order=1.97 80->160 N=80 err=2.448e-03 N=160 err=6.179e-04 order=1.99 clamped-free varEI (w=x^4): 40->80 N=40 err=1.254e-02 N=80 err=2.953e-03 order=2.09 80->160 N=80 err=2.953e-03 N=160 err=7.152e-04 order=2.05 pinned-pinned UDL (exact): 40->80 N=40 err=2.030e-05 N=80 err=5.076e-06 order=2.00 80->160 N=80 err=5.076e-06 N=160 err=1.269e-06 order=2.00 free-free on foundation: 40->80 N=40 err=7.015e-03 N=80 err=1.755e-03 order=2.00 80->160 N=80 err=1.755e-03 N=160 err=4.388e-04 order=2.00
cat > /tmp/verify2.cpp <<'EOF'
#include <cmath>
#include <cstdio>
#include <vector>
#include "beamfd/beam.hpp"
#include "beamfd/solver.hpp"
using namespace beamfd;
int main(){
// Classic cantilever, tip load P (clamped-free): w(L)=P L^3/(3EI).
{
double L=3.0, EI=2.0e6, P=1000.0;
for(std::size_t N: {50,100,200}){
Beam b(L,EI,N,Support::Clamped,Support::Free);
b.set_end_load(P,false);
auto w=BeamSolver(b).solve().deflection;
double exact=P*L*L*L/(3.0*EI);
printf("cantilever tip N=%zu w(L)=%.6e exact=%.6e relerr=%.2e\n",N,w[N],exact,std::fabs(w[N]-exact)/exact);
}
}
// clamped-pinned UDL closed form: max via standard formula; just check convergence to a reference.
// Use MMS: clamped-pinned, w=x^2(L-x)^2 has w(0)=0,w'(0)=0,w(L)=0 and w''(L)? need M(L)=0 for pinned.
// w''=2L^2-12Lx+12x^2; w''(L)=2L^2-12L^2+12L^2=2L^2 !=0. So not pinned-compatible. Use different MMS.
// clamped-pinned MMS: pick w with w(0)=w'(0)=0, w(L)=0, w''(L)=0.
// w(x)=x^2 (L-x)^2 (L-x) ? messy. Instead just confirm pinned end + clamped via a foundation MMS reference using fine-grid self-convergence.
{
double L=2.0, a=1000.0,b_=300.0; // EI=a+bx
// MMS for clamped(0)-pinned(L): choose w=x^2(L-x)^2*(?), ensure w''(L)=0.
// Let w(x)=x^2 (L-x)^3 / L. w(0)=0,w'(0)=0,w(L)=0. w''(L)=0?
// w= x^2 (L-x)^3 /L. Compute w'' at L: factor (L-x)^3 and lower powers vanish at x=L except term with (L-x)^1?
// derivatives: terms with (L-x)^k, k>=1 vanish at L. w'' will have lowest power (L-x)^1 -> 0. Good => w''(L)=0.
auto W=[&](double x){ return x*x*std::pow(L-x,3)/L; };
// q=(EI w'')''+0. Compute (EI w'')'' numerically-exact via high-order? Instead compute by analytic of g=EI*w''.
// Too messy analytically; verify self-convergence (Richardson) instead: refine and check ratio of successive diffs.
std::vector<double> prev; double preverr=0; std::size_t prevN=0;
for(std::size_t N: {40,80,160,320}){
Beam beam(L,a,N,Support::Clamped,Support::Pinned);
beam.set_ei_profile({{0,a},{L,a+b_*L}});
// set q from finite-diff of exact? We don't have q. Skip: instead drive with q from W using 4th deriv approx?
// Simpler: just impose a UDL and check self-convergence (Richardson order) of midpoint.
beam.set_distributed_load(5.0);
auto w=BeamSolver(beam).solve().deflection;
double mid=w[N/2];
if(prevN){ printf("clamped-pinned varEI UDL: N=%zu mid=%.8e d=%.2e\n",N,mid,std::fabs(mid-preverr)); }
preverr=mid; prevN=N; (void)W;
}
}
// pinned-free on foundation MMS (well posed due to foundation): w=cos(pi x/2L) style
{
double L=2.0, EI=1500.0, k0=800.0;
auto W=[&](double x){ return std::sin(M_PI*x/(2*L)); }; // w(0)=0 (pinned ok), w''(0)=0 (pinned moment ok!)
auto wpp=[&](double x){ return -std::pow(M_PI/(2*L),2)*std::sin(M_PI*x/(2*L)); };
auto wppp=[&](double x){ return -std::pow(M_PI/(2*L),3)*std::cos(M_PI*x/(2*L)); };
auto w4=[&](double x){ return std::pow(M_PI/(2*L),4)*std::sin(M_PI*x/(2*L)); };
double e1=0,e2=0; std::size_t N1=80,N2=160;
for(int it=0;it<2;++it){ std::size_t N= it==0?N1:N2;
Beam b(L,EI,N,Support::Pinned,Support::Free);
b.set_foundation_nodal(std::vector<double>(N+1,k0));
std::vector<double> q(N+1); for(std::size_t i=0;i<=N;++i){double x=(double)i*L/N; q[i]=EI*w4(x)+k0*W(x);} b.set_q_nodal(q);
b.set_end_moment(EI*wpp(L),false); b.set_end_load(-(EI*wppp(L)),false);
auto w=BeamSolver(b).solve().deflection; double e=0; for(std::size_t i=0;i<=N;++i){double x=(double)i*L/N; e=std::max(e,std::fabs(w[i]-W(x)));}
if(it==0)e1=e; else e2=e;
}
printf("pinned-free on foundation: N=%zu err=%.3e N=%zu err=%.3e order=%.2f\n",N1,e1,N2,e2,std::log(e1/e2)/std::log((double)N2/N1));
}
return 0;
}
EOF
g++ -std=c++17 -O2 -Iinclude /tmp/verify2.cpp build/libbeamfd.a -o /tmp/verify2 2>&1 | head && /tmp/verify2cantilever tip N=50 w(L)=4.498200e-03 exact=4.500000e-03 relerr=4.00e-04 cantilever tip N=100 w(L)=4.499550e-03 exact=4.500000e-03 relerr=1.00e-04 cantilever tip N=200 w(L)=4.499888e-03 exact=4.500000e-03 relerr=2.50e-05 clamped-pinned varEI UDL: N=80 mid=3.38491743e-04 d=2.03e-06 clamped-pinned varEI UDL: N=160 mid=3.39006014e-04 d=5.14e-07 clamped-pinned varEI UDL: N=320 mid=3.39135557e-04 d=1.30e-07 pinned-free on foundation: N=80 err=1.657e-05 N=160 err=4.783e-06 order=1.79 [stdout] cantilever tip N=50 w(L)=4.498200e-03 exact=4.500000e-03 relerr=4.00e-04 cantilever tip N=100 w(L)=4.499550e-03 exact=4.500000e-03 relerr=1.00e-04 cantilever tip N=200 w(L)=4.499888e-03 exact=4.500000e-03 relerr=2.50e-05 clamped-pinned varEI UDL: N=80 mid=3.38491743e-04 d=2.03e-06 clamped-pinned varEI UDL: N=160 mid=3.39006014e-04 d=5.14e-07 clamped-pinned varEI UDL: N=320 mid=3.39135557e-04 d=1.30e-07 pinned-free on foundation: N=80 err=1.657e-05 N=160 err=4.783e-06 order=1.79
cat > /tmp/verify3.cpp <<'EOF'
#include <cmath>
#include <cstdio>
#include <vector>
#include "beamfd/beam.hpp"
#include "beamfd/solver.hpp"
using namespace beamfd;
int main(){
double L=2.0, EI=1500.0, k0=800.0;
auto W=[&](double x){ return std::sin(M_PI*x/(2*L)); };
auto wpp=[&](double x){ return -std::pow(M_PI/(2*L),2)*std::sin(M_PI*x/(2*L)); };
auto wppp=[&](double x){ return -std::pow(M_PI/(2*L),3)*std::cos(M_PI*x/(2*L)); };
auto w4=[&](double x){ return std::pow(M_PI/(2*L),4)*std::sin(M_PI*x/(2*L)); };
double prev=0; std::size_t prevN=0;
for(std::size_t N : {40,80,160,320,640,1280}){
Beam b(L,EI,N,Support::Pinned,Support::Free);
b.set_foundation_nodal(std::vector<double>(N+1,k0));
std::vector<double> q(N+1); for(std::size_t i=0;i<=N;++i){double x=(double)i*L/N; q[i]=EI*w4(x)+k0*W(x);} b.set_q_nodal(q);
b.set_end_moment(EI*wpp(L),false); b.set_end_load(-(EI*wppp(L)),false);
auto w=BeamSolver(b).solve().deflection; double e=0; for(std::size_t i=0;i<=N;++i){double x=(double)i*L/N; e=std::max(e,std::fabs(w[i]-W(x)));}
if(prevN) printf("N=%4zu err=%.4e order=%.3f\n",N,e,std::log(prev/e)/std::log((double)N/prevN));
else printf("N=%4zu err=%.4e\n",N,e);
prev=e; prevN=N;
}
// Also pinned-free with constant EI, no foundation? not well posed. Try clamped-free + foundation + variable EI all together.
printf("--- clamped-free varEI + foundation + UDL + end actions, MMS w=x^4 ---\n");
{ double a=1000.0,b_=400.0,c=200.0,d=90.0; double Lc=2.5;
auto W2=[&](double x){return x*x*x*x;};
// EI=a+bx, k=c+dx ; (EI w'')''=24a-24bL? no that's for x^2(L-x)^2. recompute for w=x^4:
// w''=12x^2; g=EI*12x^2=(a+bx)12x^2; g'=24a x+36b x^2; g''=24a+72b x
auto q=[&](double x){return 24.0*a+72.0*b_*x + (c+d*x)*W2(x);};
auto gL=[&](double x){return (a+b_*x)*12.0*x*x;}; auto gpL=[&](double x){return 24.0*a*x+36.0*b_*x*x;};
double pr=0; std::size_t pn=0;
for(std::size_t N:{40,80,160,320}){
Beam beam(Lc,a,N,Support::Clamped,Support::Free);
beam.set_ei_profile({{0,a},{Lc,a+b_*Lc}}); beam.set_foundation_profile({{0,c},{Lc,c+d*Lc}});
std::vector<double> qn(N+1); for(std::size_t i=0;i<=N;++i) qn[i]=q((double)i*Lc/N); beam.set_q_nodal(qn);
beam.set_end_moment(gL(Lc),false); beam.set_end_load(-gpL(Lc),false);
auto w=BeamSolver(beam).solve().deflection; double e=0; for(std::size_t i=0;i<=N;++i){double x=(double)i*Lc/N; e=std::max(e,std::fabs(w[i]-W2(x)));}
if(pn) printf("N=%4zu err=%.4e order=%.3f\n",N,e,std::log(pr/e)/std::log((double)N/pn)); else printf("N=%4zu err=%.4e\n",N,e);
pr=e; pn=N;
}
}
return 0;
}
EOF
g++ -std=c++17 -O2 -Iinclude /tmp/verify3.cpp build/libbeamfd.a -o /tmp/verify3 2>&1|head && /tmp/verify3N= 40 err=4.6504e-05 N= 80 err=1.6570e-05 order=1.489 N= 160 err=4.7828e-06 order=1.793 N= 320 err=1.2594e-06 order=1.925 N= 640 err=1.1057e-07 order=3.510 N=1280 err=8.7822e-06 order=-6.311 --- clamped-free varEI + foundation + UDL + end actions, MMS w=x^4 --- N= 40 err=2.8403e-02 N= 80 err=6.9054e-03 order=2.040 N= 160 err=1.7014e-03 order=2.021 N= 320 err=4.2292e-04 order=2.008 [stdout] N= 40 err=4.6504e-05 N= 80 err=1.6570e-05 order=1.489 N= 160 err=4.7828e-06 order=1.793 N= 320 err=1.2594e-06 order=1.925 N= 640 err=1.1057e-07 order=3.510 N=1280 err=8.7822e-06 order=-6.311 --- clamped-free varEI + foundation + UDL + end actions, MMS w=x^4 --- N= 40 err=2.8403e-02 N= 80 err=6.9054e-03 order=2.040 N= 160 err=1.7014e-03 order=2.021 N= 320 err=4.2292e-04 order=2.008
rm -rf build && cmake -S . -B build -DCMAKE_BUILD_TYPE=Release >/dev/null 2>&1 && cmake --build build --parallel 2>&1 | grep -iE "warning|error|solver" ; echo "=== build done ==="; cd build && ctest --output-on-failure 2>&1 | tail -6 echo "=== CLI sanity (cantilever example) ==="; ./beamfd_cli ../examples/cantilever_tip.beam 2>/dev/null | tail -15 rm -f /tmp/verify*.cpp /tmp/verify /tmp/verify2 /tmp/verify3
[ 33%] Building CXX object CMakeFiles/beamfd.dir/src/solver.cpp.o
=== build done ===
Start 1: smoke
1/1 Test #1: smoke ............................ Passed 0.00 sec
100% tests passed, 0 tests failed out of 1
Total Test time (real) = 0.00 sec
=== CLI sanity (cantilever example) ===
186 2.790000e+00 4.028167e-03 2.100000e+02 -1.000000e+03
187 2.805000e+00 4.061763e-03 1.950000e+02 -1.000000e+03
188 2.820000e+00 4.095380e-03 1.800000e+02 -1.000000e+03
189 2.835000e+00 4.129018e-03 1.650000e+02 -1.000000e+03
190 2.850000e+00 4.162674e-03 1.500000e+02 -1.000000e+03
191 2.865000e+00 4.196348e-03 1.350000e+02 -1.000000e+03
192 2.880000e+00 4.230036e-03 1.200000e+02 -1.000000e+03
193 2.895000e+00 4.263738e-03 1.050000e+02 -1.000000e+03
194 2.910000e+00 4.297452e-03 9.000000e+01 -1.000000e+03
195 2.925000e+00 4.331175e-03 7.500000e+01 -1.000000e+03
196 2.940000e+00 4.364908e-03 6.000000e+01 -1.000000e+03
197 2.955000e+00 4.398647e-03 4.500000e+01 -1.000000e+03
198 2.970000e+00 4.432391e-03 3.000000e+01 -1.000000e+03
199 2.985000e+00 4.466138e-03 1.500000e+01 -1.000000e+03
200 3.000000e+00 4.499888e-03 7.709882e-09 -1.000000e+03
[stdout]
[ 33%] Building CXX object CMakeFiles/beamfd.dir/src/solver.cpp.o
=== build done ===
Start 1: smoke
1/1 Test #1: smoke ............................ Passed 0.00 sec
100% tests passed, 0 tests failed out of 1
Total Test time (real) = 0.00 sec
=== CLI sanity (cantilever example) ===
186 2.790000e+00 4.028167e-03 2.100000e+02 -1.000000e+03
187 2.805000e+00 4.061763e-03 1.950000e+02 -1.000000e+03
188 2.820000e+00 4.095380e-03 1.800000e+02 -1.000000e+03
189 2.835000e+00 4.129018e-03 1.650000e+02 -1.000000e+03
190 2.850000e+00 4.162674e-03 1.500000e+02 -1.000000e+03
191 2.865000e+00 4.196348e-03 1.350000e+02 -1.000000e+03
192 2.880000e+00 4.230036e-03 1.200000e+02 -1.000000e+03
193 2.895000e+00 4.263738e-03 1.050000e+02 -1.000000e+03
194 2.910000e+00 4.297452e-03 9.000000e+01 -1.000000e+03
195 2.925000e+00 4.331175e-03 7.500000e+01 -1.000000e+03
196 2.940000e+00 4.364908e-03 6.000000e+01 -1.000000e+03
197 2.955000e+00 4.398647e-03 4.500000e+01 -1.000000e+03
198 2.970000e+00 4.432391e-03 3.000000e+01 -1.000000e+03
199 2.985000e+00 4.466138e-03 1.500000e+01 -1.000000e+03
200 3.000000e+00 4.499888e-03 7.709882e-09 -1.000000e+03No file changes, the agent left the workspace untouched.
== Configuring (cmake) ==
-- The CXX compiler identification is GNU 11.4.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp/tmp.s7oboO3uQM/beamfd/build_grade
== Building ==
[ 13%] Building CXX object CMakeFiles/beamfd.dir/src/io.cpp.o
[ 13%] Building CXX object CMakeFiles/beamfd.dir/src/linalg.cpp.o
[ 20%] Building CXX object CMakeFiles/beamfd.dir/src/beam.cpp.o
[ 26%] Building CXX object CMakeFiles/beamfd.dir/src/solver.cpp.o
[ 33%] Linking CXX static library libbeamfd.a
[ 33%] Built target beamfd
[ 40%] Building CXX object CMakeFiles/beamfd_cli.dir/src/main.cpp.o
[ 46%] Building CXX object tests/CMakeFiles/test_invariants.dir/test_invariants.cpp.o
[ 53%] Building CXX object tests/CMakeFiles/test_mms.dir/test_mms.cpp.o
[ 60%] Building CXX object tests/CMakeFiles/test_soak.dir/test_soak.cpp.o
[ 66%] Building CXX object tests/CMakeFiles/test_convergence.dir/test_convergence.cpp.o
[ 73%] Linking CXX executable beamfd_cli
[ 73%] Built target beamfd_cli
[ 80%] Linking CXX executable test_convergence
[ 86%] Linking CXX executable test_soak
[ 86%] Built target test_convergence
[ 86%] Built target test_soak
[ 93%] Linking CXX executable test_invariants
[100%] Linking CXX executable test_mms
[100%] Built target test_invariants
[100%] Built target test_mms
== Running hidden test suite (ctest) ==
Test project /tmp/tmp.s7oboO3uQM/beamfd/build_grade
Start 1: test_mms
1/4 Test #1: test_mms ......................... Passed 0.01 sec
Start 2: test_convergence
2/4 Test #2: test_convergence ................. Passed 0.00 sec
Start 3: test_invariants
3/4 Test #3: test_invariants ..................***Failed 0.00 sec
[ PASS ] invariant_equilibrium_residual
[ FAIL ] invariant_symmetry: symmetry at node 0
[ PASS ] invariant_mechanism_rejection
[ PASS ] invariant_input_validation
----
3/4 tests passed
Start 4: test_soak
4/4 Test #4: test_soak ........................ Passed 0.01 sec
75% tests passed, 1 tests failed out of 4
Label Time Summary:
hidden = 0.03 sec*proc (4 tests)
Total Test time (real) = 0.03 sec
The following tests FAILED:
3 - test_invariants (Failed)
Errors while running CTest
FAIL: one or more hidden tests failedReproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_afcb4cb58a014b4f. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.
Trial trial_afcb4cb58a014b4f · verifier authoritative; classifier explanatory.