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
/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
tests/**
tests/test_util.hpp tests/test_smoke.cpp tests/CMakeLists.txt
/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/tests/CMakeLists.txt
1 # The shipped project ships only a tiny, non-leaky smoke test using the
2 # header-only harness in test_util.hpp. The authoritative grading is a separate
3 # HIDDEN suite injected by the verifier (tests/test.sh) at grade time, so do
4 # not rely on this smoke test to characterize correctness.
5
6 add_executable(test_smoke test_smoke.cpp)
7 target_link_libraries(test_smoke PRIVATE beamfd)
8 target_include_directories(test_smoke PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
9 add_test(NAME smoke COMMAND test_smoke)
10
List project tree excluding build
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/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 {
// Discretize d2/dx2( EI(x) w''(x) ) + k(x) w(x) = q(x) on the uniform grid
// x_i = i*dx, i = 0..N, with n = N+1 nodal unknowns w_i.
//
// Interior operator (second-order). The fourth-order term is the second
// central difference of the nodal moment M_j = EI_j * w''_j:
//
// (EI w'')''_i ~= ( M_{i-1} - 2 M_i + M_{i+1} ) / dx^2 ,
// M_j ~= EI_j ( w_{j-1} - 2 w_j + w_{j+1} ) / dx^2 ,
//
// which expands to the 5-point stencil (coefficients divided by dx^4)
//
// EI_{i-1} w_{i-2}
// - 2(EI_{i-1}+EI_i) w_{i-1}
// + (EI_{i-1}+4 EI_i+EI_{i+1}) w_i
// - 2(EI_i+EI_{i+1}) w_{i+1}
// + EI_{i+1} w_{i+2}
//
// and reduces to the classic EI/dx^4 * [1,-4,6,-4,1] biharmonic stencil for
// constant EI. The PDE is collocated at the interior nodes i = 1..N-1; the
// single ghost each such near-boundary row reaches (w_{-1} at row 1, w_{N+1}
// at row N-1) is removed using the end's secondary boundary condition, all
// second-order accurate. Rows 0 and N hold the end's primary condition.
const std::size_t n = beam_.num_nodes();
const std::size_t N = beam_.num_intervals();
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;
// Add to A(r, c), silently ignoring out-of-range columns. Out-of-range only
// happens for under-resolved meshes (N < 4) where the 4th-order stencil
// cannot fit; for any adequately refined grid every term lands in range.
auto add = [&](std::size_t r, long c, double v) {
if (c >= 0 && static_cast<std::size_t>(c) < n) {
A(r, static_cast<std::size_t>(c)) += v;
}
};
// ---- Interior PDE rows i = 1 .. N-1 -------------------------------------
for (std::size_t i = 1; i + 1 < n; ++i) {
const double eim = beam_.EI_at(i - 1);
const double eii = beam_.EI_at(i);
const double eip = beam_.EI_at(i + 1);
const long li = static_cast<long>(i);
add(i, li - 2, eim / h4);
add(i, li - 1, -2.0 * (eim + eii) / h4);
add(i, li, (eim + 4.0 * eii + eip) / h4);
add(i, li + 1, -2.0 * (eii + eip) / h4);
add(i, li + 2, eip / h4);
add(i, li, beam_.k_at(i)); // Winkler foundation
sys.b[i] = beam_.q_at(i);
}
// ---- Ghost elimination at the two near-boundary interior rows ----------
// Each end's secondary condition expresses the exterior ghost as a linear
// combination of the two nearest real nodes plus a constant:
// left : w_{-1} = a0 w_0 + a1 w_1 + cL
// right: w_{N+1} = b0 w_N + b1 w_{N-1} + cR
// clamped (w'=0): a0=0, a1= 1, c=0
// pinned (w''=0): a0=2, a1=-1, c=0
// free (EI w''=M): a0=2, a1=-1, c = M_applied * dx^2 / EI_end
if (n >= 3) {
// Left ghost folded into PDE row 1 (coefficient on w_{-1} is EI_0/dx^4).
const double cL = beam_.EI_at(0) / h4;
double a0, a1, constL = 0.0;
switch (beam_.left()) {
case Support::Clamped: a0 = 0.0; a1 = 1.0; break;
case Support::Pinned: a0 = 2.0; a1 = -1.0; break;
case Support::Free:
a0 = 2.0; a1 = -1.0;
constL = beam_.end_moment(true) * h2 / beam_.EI_at(0);
break;
}
add(1, 0, cL * a0);
add(1, 1, cL * a1);
sys.b[1] -= cL * constL;
// Right ghost folded into PDE row N-1 (coefficient on w_{N+1} is
// EI_N/dx^4).
const double cR = beam_.EI_at(N) / h4;
double b0, b1, constR = 0.0;
switch (beam_.right()) {
case Support::Clamped: b0 = 0.0; b1 = 1.0; break;
case Support::Pinned: b0 = 2.0; b1 = -1.0; break;
case Support::Free:
b0 = 2.0; b1 = -1.0;
constR = beam_.end_moment(false) * h2 / beam_.EI_at(N);
break;
}
add(N - 1, static_cast<long>(N), cR * b0);
add(N - 1, static_cast<long>(N) - 1, cR * b1);
sys.b[N - 1] -= cR * constR;
}
// ---- Primary boundary rows 0 and N -------------------------------------
// Clamped / pinned: essential condition w = 0.
// Free: the shear V = (EI w'')' equals the applied end shear. Using a
// second-order one-sided difference of the nodal moment, with M at the end
// node fixed to the applied moment by the ghost relation above:
// V_0 = (-3 M_0 + 4 M_1 - M_2)/(2 dx) = V_app, M_0 = M_app
// => 4 M_1 - M_2 = 2 dx V_app + 3 M_app
// V_N = ( 3 M_N - 4 M_{N-1} + M_{N-2})/(2 dx) = V_app, M_N = M_app
// => -4 M_{N-1} + M_{N-2} = 2 dx V_app - 3 M_app
// with M_j = EI_j (w_{j-1} - 2 w_j + w_{j+1})/dx^2.
if (beam_.left() == Support::Free) {
const double ei1 = beam_.EI_at(1);
const double ei2 = beam_.EI_at(2);
// 4 M_1 - M_2, coefficients divided by dx^2.
add(0, 0, 4.0 * ei1 / h2);
add(0, 1, (-8.0 * ei1 - ei2) / h2);
add(0, 2, (4.0 * ei1 + 2.0 * ei2) / h2);
add(0, 3, -ei2 / h2);
sys.b[0] = 2.0 * h * beam_.applied_end_shear(true) +
3.0 * beam_.end_moment(true);
} else {
A(0, 0) = 1.0;
sys.b[0] = 0.0;
}
if (beam_.right() == Support::Free) {
const double eim1 = beam_.EI_at(N - 1);
const double eim2 = beam_.EI_at(N - 2);
// -4 M_{N-1} + M_{N-2}, coefficients divided by dx^2.
add(N, static_cast<long>(N), -4.0 * eim1 / h2);
add(N, static_cast<long>(N) - 1, (8.0 * eim1 + eim2) / h2);
add(N, static_cast<long>(N) - 2, (-4.0 * eim1 - 2.0 * eim2) / h2);
add(N, static_cast<long>(N) - 3, eim2 / h2);
sys.b[N] = 2.0 * h * beam_.applied_end_shear(false) -
3.0 * beam_.end_moment(false);
} else {
A(N, N) = 1.0;
sys.b[N] = 0.0;
}
return sys;
}
BeamResult BeamSolver::solve() const {
beam_.validate(); // propagates mechanism / configuration errors
const BeamSystem sys = assemble_system();
BeamResult result;
// solve_general throws std::runtime_error on a singular system; let it
// propagate per the contract.
result.deflection = solve_general(sys.A, sys.b);
return result;
}Configure, build, run smoke test
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release >/dev/null 2>&1 && cmake --build build --parallel 2>&1 | tail -15 && cd build && ctest --output-on-failure 2>&1 | tail -20
| ~~~^~~~~~~~~~~~~~~
/opt/beamfd/src/solver.cpp:133:12: warning: 'b0' may be used uninitialized [-Wmaybe-uninitialized]
133 | add(N - 1, static_cast<long>(N), cR * b0);
| ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/opt/beamfd/src/solver.cpp:134:12: warning: 'b1' may be used uninitialized [-Wmaybe-uninitialized]
134 | add(N - 1, static_cast<long>(N) - 1, cR * b1);
| ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[ 55%] Linking CXX static library libbeamfd.a
[ 55%] Built target beamfd
[ 66%] Building CXX object CMakeFiles/beamfd_cli.dir/src/main.cpp.o
[ 77%] Building CXX object tests/CMakeFiles/test_smoke.dir/test_smoke.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) = 0.01 sec
[stdout]
| ~~~^~~~~~~~~~~~~~~
/opt/beamfd/src/solver.cpp:133:12: warning: 'b0' may be used uninitialized [-Wmaybe-uninitialized]
133 | add(N - 1, static_cast<long>(N), cR * b0);
| ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/opt/beamfd/src/solver.cpp:134:12: warning: 'b1' may be used uninitialized [-Wmaybe-uninitialized]
134 | add(N - 1, static_cast<long>(N) - 1, cR * b1);
| ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[ 55%] Linking CXX static library libbeamfd.a
[ 55%] Built target beamfd
[ 66%] Building CXX object CMakeFiles/beamfd_cli.dir/src/main.cpp.o
[ 77%] Building CXX object tests/CMakeFiles/test_smoke.dir/test_smoke.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) = 0.01 sec/opt/beamfd/src/solver.cpp
const double cL = beam_.EI_at(0) / h4;
double a0, a1, constL = 0.0; const double cL = beam_.EI_at(0) / h4;
double a0 = 0.0, a1 = 1.0, constL = 0.0;/opt/beamfd/src/solver.cpp
const double cR = beam_.EI_at(N) / h4;
double b0, b1, constR = 0.0; const double cR = beam_.EI_at(N) / h4;
double b0 = 0.0, b1 = 1.0, constR = 0.0;// Local validation against closed-form solutions + convergence order.
#include <cmath>
#include <cstdio>
#include <vector>
#include "beamfd/beam.hpp"
#include "beamfd/solver.hpp"
using namespace beamfd;
static double max_rel_err(const std::vector<double>& w,
const std::vector<double>& exact) {
double num = 0, den = 0;
for (size_t i = 0; i < w.size(); ++i) {
num = std::max(num, std::fabs(w[i] - exact[i]));
den = std::max(den, std::fabs(exact[i]));
}
return den > 0 ? num / den : num;
}
// returns max-norm absolute error
template <class F>
static double run(Support l, Support r, int N, double L, double EI, F exact,
double q = 0, double Pend = 0, bool Pleft = false,
double Mend = 0, bool Mleft = false) {
Beam beam(L, EI, N, l, r);
if (q != 0) beam.set_distributed_load(q);
if (Pend != 0) beam.set_end_load(Pend, Pleft);
if (Mend != 0) beam.set_end_moment(Mend, Mleft);
BeamSolver s(beam);
auto w = s.solve().deflection;
std::vector<double> ex(w.size());
double e = 0;
for (size_t i = 0; i < w.size(); ++i) {
ex[i] = exact(beam.node_x(i));
e = std::max(e, std::fabs(w[i] - ex[i]));
}
return e;
}
static void order(const char* name, double e1, double e2) {
double p = std::log2(e1 / e2);
printf("%-40s err(N)=%.3e err(2N)=%.3e order~%.2f\n", name, e1, e2, p);
}
int main() {
const double L = 2.0, EI = 1234.0;
// 1. Simply supported (pinned-pinned), UDL q. w = q x(L^3-2Lx^2+x^3)/(24EI)
{
double q = 7.0;
auto ex = [&](double x){ return q*x*(L*L*L - 2*L*x*x + x*x*x)/(24*EI); };
double e1 = run(Support::Pinned, Support::Pinned, 40, L, EI, ex, q);
double e2 = run(Support::Pinned, Support::Pinned, 80, L, EI, ex, q);
order("pinned-pinned UDL", e1, e2);
}
// 2. Cantilever clamped-left free-right, UDL. w=q x^2(x^2-4Lx+6L^2)/(24EI)
{
double q = 5.0;
auto ex = [&](double x){ return q*x*x*(x*x - 4*L*x + 6*L*L)/(24*EI); };
double e1 = run(Support::Clamped, Support::Free, 40, L, EI, ex, q);
double e2 = run(Support::Clamped, Support::Free, 80, L, EI, ex, q);
order("cantilever UDL", e1, e2);
}
// 3. Cantilever, tip load P (downward, at right). w = P x^2(3L-x)/(6EI)
{
double P = 9.0;
auto ex = [&](double x){ return P*x*x*(3*L - x)/(6*EI); };
double e1 = run(Support::Clamped, Support::Free, 40, L, EI, ex, 0, P, false);
double e2 = run(Support::Clamped, Support::Free, 80, L, EI, ex, 0, P, false);
order("cantilever tip load", e1, e2);
}
// 4. Cantilever, tip moment M at right. w = M x^2/(2EI)
{
double M = 11.0;
auto ex = [&](double x){ return M*x*x/(2*EI); };
double e1 = run(Support::Clamped, Support::Free, 40, L, EI, ex, 0,0,false, M, false);
double e2 = run(Support::Clamped, Support::Free, 80, L, EI, ex, 0,0,false, M, false);
order("cantilever tip moment", e1, e2);
}
// 5. Clamped-clamped UDL. w = q x^2 (L-x)^2 /(24 EI)
{
double q = 4.0;
auto ex = [&](double x){ return q*x*x*(L-x)*(L-x)/(24*EI); };
double e1 = run(Support::Clamped, Support::Clamped, 40, L, EI, ex, q);
double e2 = run(Support::Clamped, Support::Clamped, 80, L, EI, ex, q);
order("clamped-clamped UDL", e1, e2);
}
// 6. Clamped-pinned UDL. w = q x^2 (3L^2 -5Lx +2x^2)/(48 EI)
{
double q = 6.0;
auto ex = [&](double x){ return q*x*x*(3*L*L -5*L*x +2*x*x)/(48*EI); };
double e1 = run(Support::Clamped, Support::Pinned, 40, L, EI, ex, q);
double e2 = run(Support::Clamped, Support::Pinned, 80, L, EI, ex, q);
order("clamped-pinned UDL", e1, e2);
}
// 7. Manufactured variable EI + foundation, free-free with foundation:
// pick w(x), EI(x), k(x), compute q = (EI w'')'' + k w, set end actions.
{
// w = sin(pi x / L); EI = EI0(1+0.5 x/L); k = k0(1+ x/L)
double EI0 = 800.0, k0 = 50.0, kc = M_PI/L;
auto W = [&](double x){ return std::sin(kc*x); };
auto W2 = [&](double x){ return -kc*kc*std::sin(kc*x); };
auto W3 = [&](double x){ return -kc*kc*kc*std::cos(kc*x); };
auto W4 = [&](double x){ return kc*kc*kc*kc*std::sin(kc*x); };
auto E = [&](double x){ return EI0*(1+0.5*x/L); };
auto Ep = [&](double x){ return EI0*0.5/L; };
auto K = [&](double x){ return k0*(1+x/L); };
// (EI w'')'' = EI'' w'' + 2 EI' w''' + EI w''''; EI''=0
auto Q = [&](double x){ return 2*Ep(x)*W3(x) + E(x)*W4(x) + K(x)*W(x); };
// M = EI w''; V = (EI w'')' = EI' w'' + EI w'''
auto Vf = [&](double x){ return Ep(x)*W2(x) + E(x)*W3(x); };
auto Mf = [&](double x){ return E(x)*W2(x); };
auto build = [&](int N){
Beam beam(L, EI0, N, Support::Free, Support::Free);
std::vector<double> ei(N+1), kk(N+1), qq(N+1);
for (int i=0;i<=N;i++){ double x=beam.node_x(i); ei[i]=E(x); kk[i]=K(x); qq[i]=Q(x);}
beam.set_ei_nodal(ei); beam.set_foundation_nodal(kk); beam.set_q_nodal(qq);
// end actions: applied_end_shear = V required; but setter takes force P with V=-P
// left: V(0) = Vf(0) => P_left = -Vf(0)
beam.set_end_load(-Vf(0.0), true);
beam.set_end_load( Vf(L), false);
beam.set_end_moment(Mf(0.0), true);
beam.set_end_moment(Mf(L), false);
BeamSolver s(beam);
auto w=s.solve().deflection; double e=0;
for(int i=0;i<=N;i++) e=std::max(e,std::fabs(w[i]-W(beam.node_x(i))));
return e;
};
double e1=build(40), e2=build(80);
order("varEI+foundation free-free (mfd)", e1, e2);
}
return 0;
}
/opt/beamfd/tests/validate.cpp
beam.set_end_load(-Vf(0.0), true);
beam.set_end_load( Vf(L), false); beam.set_end_load(-Vf(0.0), true);
beam.set_end_load(-Vf(L), false);Compile and run validation
cd /opt/beamfd && g++ -std=c++17 -O2 -Iinclude tests/validate.cpp src/beam.cpp src/solver.cpp src/linalg.cpp -o /tmp/validate 2>&1 | tail -20 && /tmp/validate
pinned-pinned UDL err(N)=5.909e-07 err(2N)=1.477e-07 order~2.00 cantilever UDL err(N)=5.065e-06 err(2N)=1.266e-06 order~2.00 cantilever tip load err(N)=6.078e-06 err(2N)=1.519e-06 order~2.00 cantilever tip moment err(N)=1.253e-12 err(2N)=1.731e-11 order~-3.79 clamped-clamped UDL err(N)=6.753e-07 err(2N)=1.688e-07 order~2.00 clamped-pinned UDL err(N)=1.084e-06 err(2N)=2.711e-07 order~2.00 varEI+foundation free-free (mfd) err(N)=1.692e-01 err(2N)=4.340e-02 order~1.96 [stdout] pinned-pinned UDL err(N)=5.909e-07 err(2N)=1.477e-07 order~2.00 cantilever UDL err(N)=5.065e-06 err(2N)=1.266e-06 order~2.00 cantilever tip load err(N)=6.078e-06 err(2N)=1.519e-06 order~2.00 cantilever tip moment err(N)=1.253e-12 err(2N)=1.731e-11 order~-3.79 clamped-clamped UDL err(N)=6.753e-07 err(2N)=1.688e-07 order~2.00 clamped-pinned UDL err(N)=1.084e-06 err(2N)=2.711e-07 order~2.00 varEI+foundation free-free (mfd) err(N)=1.692e-01 err(2N)=4.340e-02 order~1.96
Remove temp file, rebuild, run tests
rm -f tests/validate.cpp && cmake --build build --parallel 2>&1 | grep -iE "error|warning" | head; echo "---build clean---"; cd build && ctest --output-on-failure 2>&1 | tail -5
---build clean--- 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] ---build clean--- 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
No 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.bnfEtutN9k/beamfd/build_grade
== Building ==
[ 6%] 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
[ 53%] Building CXX object tests/CMakeFiles/test_mms.dir/test_mms.cpp.o
[ 53%] Building CXX object tests/CMakeFiles/test_invariants.dir/test_invariants.cpp.o
[ 60%] Building CXX object tests/CMakeFiles/test_convergence.dir/test_convergence.cpp.o
[ 66%] Building CXX object tests/CMakeFiles/test_soak.dir/test_soak.cpp.o
[ 73%] Linking CXX executable beamfd_cli
[ 73%] Built target beamfd_cli
[ 80%] Linking CXX executable test_convergence
[ 86%] Linking CXX executable test_mms
[ 86%] Built target test_convergence
[ 93%] Linking CXX executable test_soak
[100%] Linking CXX executable test_invariants
[100%] Built target test_soak
[100%] Built target test_mms
[100%] Built target test_invariants
== Running hidden test suite (ctest) ==
Test project /tmp/tmp.bnfEtutN9k/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 0.01 sec
Start 3: test_invariants
3/4 Test #3: test_invariants .................. Passed 0.00 sec
Start 4: test_soak
4/4 Test #4: test_soak ........................ Passed 0.01 sec
100% tests passed, 0 tests failed out of 4
Label Time Summary:
hidden = 0.03 sec*proc (4 tests)
Total Test time (real) = 0.03 sec
PASS: all hidden tests passedReproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_e56e79f512e3436e. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.
Trial trial_e56e79f512e3436e · verifier authoritative; classifier explanatory.