tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it./opt/orbit2d/include/orbit2d/types.hpp
1 #ifndef ORBIT2D_TYPES_HPP
2 #define ORBIT2D_TYPES_HPP
3
4 #include <cstddef>
5
6 namespace orbit2d {
7
8 /// Planar phase-space state of the massless test particle, expressed in the
9 /// co-rotating (synodic) frame of the two primaries: position (x, y) and
10 /// velocity (vx, vy), both measured *relative to the rotating frame*. All
11 /// quantities are nondimensional (see instruction.md for the unit system).
12 /// This is a plain value type used throughout the engine.
13 struct State {
14 double x{0.0};
15 double y{0.0};
16 double vx{0.0};
17 double vy{0.0};
18 };
19
20 /// Element-wise scaled-add: returns a + h * b. Convenience for combining
21 /// weighted sums of states. Fully implemented (support code).
22 inline State axpy(const State& a, double h, const State& b) {
23 return State{a.x + h * b.x, a.y + h * b.y, a.vx + h * b.vx,
24 a.vy + h * b.vy};
25 }
26
27 } // namespace orbit2d
28
29 #endif // ORBIT2D_TYPES_HPP
30
/opt/orbit2d/src/system.cpp
1 #include "orbit2d/system.hpp"
2
3 #include <cmath>
4 #include <stdexcept>
5
6 namespace orbit2d {
7
8 System::System(double mu) : mu_(mu) {
9 if (!(mu_ > 0.0) || !(mu_ <= 0.5)) {
10 throw std::invalid_argument("System: mu must satisfy 0 < mu <= 1/2");
11 }
12 }
13
14 double System::radius(const State& s) const {
15 return std::sqrt(s.x * s.x + s.y * s.y);
16 }
17
18 double System::r1(const State& s) const {
19 const double dx = s.x - primary1_x();
20 return std::sqrt(dx * dx + s.y * s.y);
21 }
22
23 double System::r2(const State& s) const {
24 const double dx = s.x - primary2_x();
25 return std::sqrt(dx * dx + s.y * s.y);
26 }
27
28 // ============================================================================
29 // TODO(candidate): Implement the dynamics core described in instruction.md:
30 // the assembled right-hand side rhs() and the conserved integral jacobi().
31 // Both ship as stubs:
32 // * rhs() returns an all-zero derivative, so the particle never accelerates
33 // (and, with the stubbed integrator, never moves);
34 // * jacobi() returns 0, which is not the model's integral of motion.
35 // Replace both bodies with correct implementations derived from the physical
36 // model and conventions in instruction.md. Use the provided geometry helpers
37 // (primary positions, r1(), r2()). Do NOT change the public signatures.
38 //
39 // rhs(): the first two derivative components are the kinematic identities
40 // x' = vx, y' = vy. The velocity-derivative components are the particle's
41 // rotating-frame acceleration. Throw std::runtime_error if the particle sits
42 // exactly on a primary (r1 == 0 or r2 == 0).
43 // jacobi(): return the model's isolating integral in the sign/scale convention
44 // fixed by instruction.md. Throw std::runtime_error on a primary singularity.
45 // ============================================================================
46
47 State System::rhs(const State& s) const {
48 // TODO(candidate): assemble and return the first-order right-hand side.
49 (void)s;
50 return State{}; // zero derivative -> wrong (no acceleration)
51 }
52
53 double System::jacobi(const State& s) const {
54 // TODO(candidate): compute and return the model's conserved integral.
55 (void)s;
56 return 0.0; // wrong: not the Jacobi integral
57 }
58
59 } // namespace orbit2d
60
/opt/orbit2d/src/solver.cpp
1 #include "orbit2d/integrator.hpp"
2
3 #include <cstddef>
4 #include <stdexcept>
5 #include <vector>
6
7 #include "orbit2d/system.hpp"
8 #include "orbit2d/types.hpp"
9
10 namespace orbit2d {
11
12 // ============================================================================
13 // TODO(candidate): Implement the fixed-step time integrator and the
14 // event-terminated propagation for the model described in instruction.md.
15 //
16 // The three member functions below ship as stubs: step() returns its input
17 // state UNCHANGED (the particle never moves), propagate() merely records that
18 // frozen state with the wrong final time, and propagate_to_event() reports that
19 // no event was found. Every trajectory is therefore wrong and the test suite
20 // FAILS. Replace the stub bodies with correct implementations.
21 //
22 // Do NOT change the public signatures declared in
23 // include/orbit2d/integrator.hpp. Advance the dynamics through System::rhs
24 // (System holds the model and its parameter); the State helper axpy(a, h, b) ==
25 // a + h*b from include/orbit2d/types.hpp is available for combining stages and
26 // forming weighted sums. You should only need to edit this file together with
27 // the dynamics core in src/system.cpp.
28 //
29 // The required behaviour -- the numerical scheme and its order of accuracy, the
30 // trajectory bookkeeping, the conserved-quantity tolerances, the event
31 // definition and its refinement onto the event surface -- is specified in
32 // instruction.md and locked down by the hidden test suite. A do-nothing
33 // integrator trivially "conserves" the integral of motion but fails because the
34 // particle does not move; the suite pairs every invariant with an evolution
35 // check.
36 //
37 // step(): require dt > 0 (else std::invalid_argument).
38 // propagate(): require dt > 0 (else std::invalid_argument); record the
39 // initial state as states[0], advance n_steps times.
40 // propagate_to_event(): require dt > 0 and t_max > 0 (else
41 // std::invalid_argument); locate and refine the event as
42 // specified in instruction.md.
43 // ============================================================================
44
45 State Integrator::step(const State& s, double dt) const {
46 // TODO(candidate): perform one valid step using system_.rhs and return the
47 // advanced state.
48 (void)dt;
49 (void)system_;
50 return s; // unchanged -> wrong (particle frozen)
51 }
52
53 Trajectory Integrator::propagate(const State& initial, double dt,
54 std::size_t n_steps) const {
55 // TODO(candidate): record the initial state, then step n_steps times.
56 (void)dt;
57 Trajectory traj;
58 traj.states.assign(n_steps + 1, initial); // never evolved -> wrong
59 traj.steps = n_steps;
60 traj.time = 0.0; // wrong: should be n_steps * dt
61 return traj;
62 }
63
64 EventHit Integrator::propagate_to_event(const State& initial, double dt,
65 double t_max) const {
66 // TODO(candidate): integrate until the first qualifying x-axis crossing and
67 // refine it onto the event surface.
68 (void)dt;
69 (void)t_max;
70 EventHit hit;
71 hit.state = initial;
72 hit.time = 0.0;
73 hit.steps = 0;
74 hit.found = false; // wrong: never locates the event
75 return hit;
76 }
77
78 } // namespace orbit2d
79
/opt/orbit2d/include/orbit2d/system.hpp
1 #ifndef ORBIT2D_SYSTEM_HPP
2 #define ORBIT2D_SYSTEM_HPP
3
4 #include "orbit2d/types.hpp"
5
6 namespace orbit2d {
7
8 /// Planar two-primary model in the co-rotating (synodic) frame.
9 ///
10 /// Two primaries move on a fixed circular orbit about their common barycenter;
11 /// the engine works in the frame that rotates with them, so both primaries sit
12 /// at FIXED positions on the x-axis and the (massless) test particle moves under
13 /// their combined gravity plus the fictitious forces of the rotating frame. The
14 /// unit system is nondimensional: total primary mass = 1, primary separation =
15 /// 1, and the frame's angular rate = 1 (all units chosen accordingly). See
16 /// instruction.md for the full physical specification and conventions.
17 ///
18 /// The single physical parameter is the mass parameter
19 /// mu = m_secondary / (m_primary + m_secondary) in (0, 1/2],
20 /// the mass FRACTION carried by the smaller primary (this is NOT G*M). With this
21 /// convention the heavier primary has mass (1 - mu) and the lighter has mass mu.
22 ///
23 /// This class is a data container plus pure-geometry helpers (the primary
24 /// positions and the two primary-relative distances) that ARE provided, and the
25 /// dynamics core (the assembled right-hand side of the equations of motion and
26 /// the model's conserved integral) which is NOT , those are implemented in
27 /// src/system.cpp and ship as stubs for the candidate to complete.
28 class System {
29 public:
30 /// Construct with mass parameter `mu`. Throws std::invalid_argument unless
31 /// 0 < mu <= 1/2.
32 explicit System(double mu);
33
34 double mu() const { return mu_; }
35
36 /// x-coordinate of the heavier primary (mass 1 - mu). Support code.
37 double primary1_x() const { return -mu_; }
38
39 /// x-coordinate of the lighter primary (mass mu). Support code.
40 double primary2_x() const { return 1.0 - mu_; }
41
42 /// Distance from the test particle to the heavier primary. Support code.
43 double r1(const State& s) const;
44
45 /// Distance from the test particle to the lighter primary. Support code.
46 double r2(const State& s) const;
47
48 /// Distance from the barycentre (frame origin), sqrt(x^2 + y^2). Support
49 /// code; provided for convenience only.
50 double radius(const State& s) const;
51
52 // ------------------------------------------------------------------------
53 // DYNAMICS CORE -- ships as a stub in src/system.cpp (see the TODO there).
54 // ------------------------------------------------------------------------
55
56 /// Right-hand side f(s) of the first-order system s' = f(s) for this model,
57 /// with s = (x, y, vx, vy). The first two components are the kinematic
58 /// identities x' = vx, y' = vy; the velocity-derivative components encode
59 /// the particle's acceleration in the rotating frame (the combined gravity
60 /// of both primaries together with the rotating-frame fictitious forces).
61 /// Throws std::runtime_error if the particle sits exactly on either primary
62 /// (a gravitational singularity). NOT IMPLEMENTED in the shipped stub.
63 State rhs(const State& s) const;
64
65 /// The model's single isolating integral of motion -- the Jacobi integral
66 /// (the rotating-frame analogue of energy), conserved along every exact
67 /// trajectory. See instruction.md for the sign/scale convention and numeric
68 /// anchors. Throws std::runtime_error on a primary singularity. NOT
69 /// IMPLEMENTED in the shipped stub.
70 double jacobi(const State& s) const;
71
72 private:
73 double mu_{0.0};
74 };
75
76 } // namespace orbit2d
77
78 #endif // ORBIT2D_SYSTEM_HPP
79
/opt/orbit2d/include/orbit2d/integrator.hpp
1 #ifndef ORBIT2D_INTEGRATOR_HPP
2 #define ORBIT2D_INTEGRATOR_HPP
3
4 #include <cstddef>
5 #include <vector>
6
7 #include "orbit2d/system.hpp"
8 #include "orbit2d/types.hpp"
9
10 namespace orbit2d {
11
12 /// Result of a fixed-step propagation.
13 struct Trajectory {
14 /// Sampled states, one per recorded step. states[0] is the initial state
15 /// and states.back() is the state at the final time. Length is
16 /// n_steps + 1.
17 std::vector<State> states;
18
19 /// Number of integration steps actually taken.
20 std::size_t steps{0};
21
22 /// Final simulated time = steps * dt (in nondimensional time units).
23 double time{0.0};
24 };
25
26 /// Result of an event-terminated propagation (see Integrator::propagate_to_event).
27 struct EventHit {
28 /// The state at the located event, refined onto the event surface.
29 State state{};
30
31 /// The time (from the start of the propagation) at which the event occurs.
32 double time{0.0};
33
34 /// Number of whole base steps taken before the bracketing interval that
35 /// contained the event (diagnostic; not checked for an exact value).
36 std::size_t steps{0};
37
38 /// True iff an event was located before the time budget was exhausted.
39 bool found{false};
40 };
41
42 /// Fixed-step time integrator for the dynamical model defined by `System`. The
43 /// integrator is method-agnostic to the caller: it advances `System::rhs` and
44 /// records states; the numerical scheme is part of the contract (see
45 /// instruction.md), not of this interface.
46 class Integrator {
47 public:
48 explicit Integrator(const System& system) : system_(system) {}
49
50 /// Advance a single state by ONE step of size `dt`, returning the state at
51 /// the next time level. `dt` must be strictly positive (throws
52 /// std::invalid_argument otherwise).
53 State step(const State& s, double dt) const;
54
55 /// Propagate `initial` for `n_steps` steps of size `dt`, recording every
56 /// intermediate state. Returns a Trajectory with states.size() ==
57 /// n_steps + 1, steps == n_steps, time == n_steps * dt. `dt` must be
58 /// strictly positive (throws std::invalid_argument otherwise). Zero steps
59 /// returns just the initial state at time 0.
60 Trajectory propagate(const State& initial, double dt,
61 std::size_t n_steps) const;
62
63 /// Propagate `initial` with base step `dt` until the FIRST x-axis crossing
64 /// in the negative-y sense strictly after t = 0 (the value y(t) passing
65 /// from positive to negative), then refine the crossing onto the event
66 /// surface y = 0. Search no longer than `t_max`. See instruction.md for the
67 /// precise event definition, the crossing sense, and the refinement
68 /// tolerance the located state must satisfy. `dt` must be strictly positive
69 /// and `t_max` strictly positive (throws std::invalid_argument otherwise).
70 /// If no qualifying crossing occurs within `t_max`, returns an EventHit with
71 /// found == false.
72 EventHit propagate_to_event(const State& initial, double dt,
73 double t_max) const;
74
75 private:
76 const System& system_;
77 };
78
79 } // namespace orbit2d
80
81 #endif // ORBIT2D_INTEGRATOR_HPP
82
/opt/orbit2d/src/system.cpp
State System::rhs(const State& s) const {
// TODO(candidate): assemble and return the first-order right-hand side.
(void)s;
return State{}; // zero derivative -> wrong (no acceleration)
}
double System::jacobi(const State& s) const {
// TODO(candidate): compute and return the model's conserved integral.
(void)s;
return 0.0; // wrong: not the Jacobi integral
}State System::rhs(const State& s) const {
const double d1 = r1(s);
const double d2 = r2(s);
if (d1 == 0.0 || d2 == 0.0) {
throw std::runtime_error("System::rhs: particle on a primary (singularity)");
}
const double m1 = 1.0 - mu_; // heavier primary, at x = -mu
const double m2 = mu_; // lighter primary, at x = 1 - mu
const double r1c = d1 * d1 * d1;
const double r2c = d2 * d2 * d2;
const double dx1 = s.x - primary1_x(); // x + mu
const double dx2 = s.x - primary2_x(); // x - (1 - mu)
// Rotating-frame acceleration: gravity of both primaries + centrifugal
// (the (x, y) terms) + Coriolis (the velocity-coupled terms, sense fixed by
// the +z unit rotation).
const double ax =
2.0 * s.vy + s.x - m1 * dx1 / r1c - m2 * dx2 / r2c;
const double ay =
-2.0 * s.vx + s.y - m1 * s.y / r1c - m2 * s.y / r2c;
return State{s.vx, s.vy, ax, ay};
}
double System::jacobi(const State& s) const {
const double d1 = r1(s);
const double d2 = r2(s);
if (d1 == 0.0 || d2 == 0.0) {
throw std::runtime_error("System::jacobi: particle on a primary (singularity)");
}
const double m1 = 1.0 - mu_;
const double m2 = mu_;
const double v2 = s.vx * s.vx + s.vy * s.vy;
// Jacobi integral C = 2*Omega - v^2, with
// Omega = 1/2 (x^2 + y^2) + (1-mu)/r1 + mu/r2.
return (s.x * s.x + s.y * s.y) + 2.0 * m1 / d1 + 2.0 * m2 / d2 - v2;
}/opt/orbit2d/src/solver.cpp
State Integrator::step(const State& s, double dt) const {
// TODO(candidate): perform one valid step using system_.rhs and return the
// advanced state.
(void)dt;
(void)system_;
return s; // unchanged -> wrong (particle frozen)
}
Trajectory Integrator::propagate(const State& initial, double dt,
std::size_t n_steps) const {
// TODO(candidate): record the initial state, then step n_steps times.
(void)dt;
Trajectory traj;
traj.states.assign(n_steps + 1, initial); // never evolved -> wrong
traj.steps = n_steps;
traj.time = 0.0; // wrong: should be n_steps * dt
return traj;
}
EventHit Integrator::propagate_to_event(const State& initial, double dt,
double t_max) const {
// TODO(candidate): integrate until the first qualifying x-axis crossing and
// refine it onto the event surface.
(void)dt;
(void)t_max;
EventHit hit;
hit.state = initial;
hit.time = 0.0;
hit.steps = 0;
hit.found = false; // wrong: never locates the event
return hit;
}State Integrator::step(const State& s, double dt) const {
if (!(dt > 0.0)) {
throw std::invalid_argument("Integrator::step: dt must be positive");
}
// Classic four-stage Runge-Kutta (RK4): fourth-order global accuracy and,
// because it approximates the exact (time-reversible) flow to that order,
// it respects the system's reflection/time-reversal symmetry to scheme
// accuracy.
const State k1 = system_.rhs(s);
const State k2 = system_.rhs(axpy(s, 0.5 * dt, k1));
const State k3 = system_.rhs(axpy(s, 0.5 * dt, k2));
const State k4 = system_.rhs(axpy(s, dt, k3));
State next = s;
next = axpy(next, dt / 6.0, k1);
next = axpy(next, dt / 3.0, k2);
next = axpy(next, dt / 3.0, k3);
next = axpy(next, dt / 6.0, k4);
return next;
}
Trajectory Integrator::propagate(const State& initial, double dt,
std::size_t n_steps) const {
if (!(dt > 0.0)) {
throw std::invalid_argument("Integrator::propagate: dt must be positive");
}
Trajectory traj;
traj.states.reserve(n_steps + 1);
traj.states.push_back(initial);
State s = initial;
for (std::size_t i = 0; i < n_steps; ++i) {
s = step(s, dt);
traj.states.push_back(s);
}
traj.steps = n_steps;
traj.time = static_cast<double>(n_steps) * dt;
return traj;
}
EventHit Integrator::propagate_to_event(const State& initial, double dt,
double t_max) const {
if (!(dt > 0.0)) {
throw std::invalid_argument(
"Integrator::propagate_to_event: dt must be positive");
}
if (!(t_max > 0.0)) {
throw std::invalid_argument(
"Integrator::propagate_to_event: t_max must be positive");
}
State s = initial;
double t = 0.0;
std::size_t nstep = 0;
while (t < t_max) {
const State s_next = step(s, dt);
// Downward x-axis crossing: y passes from strictly positive to
// non-positive over this base step.
if (s.y > 0.0 && s_next.y <= 0.0) {
// Refine the crossing time tau in (0, dt] by bisection, stepping
// directly from the bracket's left state so the returned state is
// produced by the same dynamics and lands on the surface y = 0.
double lo = 0.0; // y(lo) = s.y > 0
double hi = dt; // y(hi) = s_next.y <= 0
State located = s_next;
double tau = dt;
for (int it = 0; it < 100; ++it) {
const double mid = 0.5 * (lo + hi);
const State sm = step(s, mid);
if (std::abs(sm.y) < 1e-9) {
located = sm;
tau = mid;
break;
}
if (sm.y > 0.0) {
lo = mid;
} else {
hi = mid;
located = sm;
tau = mid;
}
}
const double event_time = t + tau;
if (event_time <= t_max) {
EventHit hit;
hit.state = located;
hit.time = event_time;
hit.steps = nstep;
hit.found = true;
return hit;
}
// The first crossing lies beyond the time budget.
break;
}
t += dt;
s = s_next;
++nstep;
}
EventHit hit;
hit.found = false;
return hit;
}/opt/orbit2d/src/solver.cpp
#include <cstddef> #include <stdexcept> #include <vector>
#include <cmath> #include <cstddef> #include <stdexcept> #include <vector>
Configure and build the project
cmake -S /opt/orbit2d -B /opt/orbit2d/build -DCMAKE_BUILD_TYPE=Release >/dev/null 2>&1 && cmake --build /opt/orbit2d/build --parallel 2>&1 | tail -20
[ 12%] Building CXX object CMakeFiles/orbit2d.dir/src/system.cpp.o [ 25%] Building CXX object CMakeFiles/orbit2d.dir/src/solver.cpp.o [ 37%] Building CXX object CMakeFiles/orbit2d.dir/src/io.cpp.o [ 50%] Linking CXX static library liborbit2d.a [ 50%] Built target orbit2d [ 62%] Building CXX object CMakeFiles/orbit2d_cli.dir/src/main.cpp.o [ 75%] Building CXX object tests/CMakeFiles/test_smoke.dir/test_smoke.cpp.o [ 87%] Linking CXX executable orbit2d_cli [ 87%] Built target orbit2d_cli [100%] Linking CXX executable test_smoke [100%] Built target test_smoke [stdout] [ 12%] Building CXX object CMakeFiles/orbit2d.dir/src/system.cpp.o [ 25%] Building CXX object CMakeFiles/orbit2d.dir/src/solver.cpp.o [ 37%] Building CXX object CMakeFiles/orbit2d.dir/src/io.cpp.o [ 50%] Linking CXX static library liborbit2d.a [ 50%] Built target orbit2d [ 62%] Building CXX object CMakeFiles/orbit2d_cli.dir/src/main.cpp.o [ 75%] Building CXX object tests/CMakeFiles/test_smoke.dir/test_smoke.cpp.o [ 87%] Linking CXX executable orbit2d_cli [ 87%] Built target orbit2d_cli [100%] Linking CXX executable test_smoke [100%] Built target test_smoke
Run the test suite
cd /opt/orbit2d/build && ctest --output-on-failure 2>&1 | tail -20
Test project /opt/orbit2d/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]
Test project /opt/orbit2d/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 secVerify order, conservation, symmetry, event
cat > /tmp/verify.cpp <<'EOF'
#include "orbit2d/system.hpp"
#include "orbit2d/integrator.hpp"
#include <cstdio>
#include <cmath>
using namespace orbit2d;
int main(){
System sys(0.1);
Integrator itg(sys);
// Jacobi conservation along a trajectory
State s0{0.5,0.0,0.0,0.6};
double j0 = sys.jacobi(s0);
auto tr = itg.propagate(s0, 1e-3, 5000);
double jend = sys.jacobi(tr.states.back());
printf("Jacobi drift: %.3e (j0=%.6f)\n", std::fabs(jend-j0), j0);
printf("traj size=%zu time=%.6f\n", tr.states.size(), tr.time);
// Order of accuracy: compare to reference at small dt
double T=2.0;
auto ref = itg.propagate(s0, T/100000.0, 100000).states.back();
double prev=0;
for(int k=0;k<3;k++){
long n = 200L<<k;
auto e = itg.propagate(s0, T/n, n).states.back();
double err = std::hypot(std::hypot(e.x-ref.x,e.y-ref.y), std::hypot(e.vx-ref.vx,e.vy-ref.vy));
printf("n=%ld err=%.3e", n, err);
if(prev>0) printf(" ratio=%.2f (expect ~16)", prev/err);
printf("\n");
prev=err;
}
// Time-reversal symmetry: R=(x,-y,-vx,vy); forward, reflect, forward => R(s0)
auto R=[](State s){ return State{s.x,-s.y,-s.vx,s.vy}; };
double dt=1e-3; long n=2000;
State a = itg.propagate(s0, dt, n).states.back();
State b = itg.propagate(R(a), dt, n).states.back();
State target = R(s0);
double sym = std::hypot(std::hypot(b.x-target.x,b.y-target.y),std::hypot(b.vx-target.vx,b.vy-target.vy));
printf("symmetry recovery err: %.3e\n", sym);
// Event: start above axis moving so it crosses down
State se{0.5,0.0,0.1,0.6};
auto hit = itg.propagate_to_event(se, 1e-2, 50.0);
printf("event found=%d time=%.6f y=%.3e\n", hit.found, hit.time, hit.state.y);
return 0;
}
EOF
g++ -std=c++17 -O2 -I/opt/orbit2d/include /tmp/verify.cpp /opt/orbit2d/build/liborbit2d.a -o /tmp/verify && /tmp/verifyJacobi drift: 5.434e-12 (j0=3.390000) traj size=5001 time=5.000000 n=200 err=1.214e-06 n=400 err=7.159e-08 ratio=16.96 (expect ~16) n=800 err=4.337e-09 ratio=16.51 (expect ~16) symmetry recovery err: 7.619e-12 event found=1 time=1.711450 y=-3.696e-11 [stdout] Jacobi drift: 5.434e-12 (j0=3.390000) traj size=5001 time=5.000000 n=200 err=1.214e-06 n=400 err=7.159e-08 ratio=16.96 (expect ~16) n=800 err=4.337e-09 ratio=16.51 (expect ~16) symmetry recovery err: 7.619e-12 event found=1 time=1.711450 y=-3.696e-11
Verify equilibrium, singularity, validation
cat > /tmp/v2.cpp <<'EOF'
#include "orbit2d/system.hpp"
#include "orbit2d/integrator.hpp"
#include <cstdio>
#include <cmath>
#include <stdexcept>
using namespace orbit2d;
int main(){
System sys(0.1); Integrator itg(sys);
// L4 equilibrium at (1/2-mu, sqrt(3)/2) at rest must stay put
State L4{0.4, std::sqrt(3.0)/2.0, 0.0, 0.0};
auto e = itg.propagate(L4, 1e-3, 10000).states.back();
printf("L4 drift after T=10: dx=%.2e dy=%.2e dvx=%.2e dvy=%.2e\n",
e.x-L4.x, e.y-L4.y, e.vx, e.vy);
// rhs at L4 ~ 0
State f = sys.rhs(L4);
printf("rhs@L4 accel: (%.2e, %.2e)\n", f.vx, f.vy);
// singularity throw
try { sys.rhs(State{-0.1,0.0,0,0}); printf("NO THROW (bad)\n"); }
catch(const std::runtime_error&){ printf("rhs throws on primary: ok\n"); }
try { sys.jacobi(State{0.9,0.0,0,0}); printf("NO THROW (bad)\n"); }
catch(const std::runtime_error&){ printf("jacobi throws on primary: ok\n"); }
// arg validation
try { itg.step(L4,-1); } catch(const std::invalid_argument&){ printf("step neg dt throws: ok\n"); }
return 0;
}
EOF
g++ -std=c++17 -O2 -I/opt/orbit2d/include /tmp/v2.cpp /opt/orbit2d/build/liborbit2d.a -o /tmp/v2 && /tmp/v2L4 drift after T=10: dx=0.00e+00 dy=0.00e+00 dvx=-1.01e-16 dvy=-8.14e-17 rhs@L4 accel: (-1.39e-16, -2.78e-16) rhs throws on primary: ok jacobi throws on primary: ok step neg dt throws: ok [stdout] L4 drift after T=10: dx=0.00e+00 dy=0.00e+00 dvx=-1.01e-16 dvy=-8.14e-17 rhs@L4 accel: (-1.39e-16, -2.78e-16) rhs throws on primary: ok jacobi throws on primary: ok step neg dt throws: ok
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.XC5xwq37w0/orbit2d/build_grade
== Building ==
[ 5%] Building CXX object CMakeFiles/orbit2d.dir/src/system.cpp.o
[ 10%] Building CXX object CMakeFiles/orbit2d.dir/src/io.cpp.o
[ 15%] Building CXX object CMakeFiles/orbit2d.dir/src/solver.cpp.o
[ 20%] Linking CXX static library liborbit2d.a
[ 20%] Built target orbit2d
[ 25%] Building CXX object CMakeFiles/orbit2d_cli.dir/src/main.cpp.o
[ 30%] Building CXX object tests/CMakeFiles/test_field.dir/test_field.cpp.o
[ 35%] Building CXX object tests/CMakeFiles/test_symmetry.dir/test_symmetry.cpp.o
[ 40%] Building CXX object tests/CMakeFiles/test_equilibria.dir/test_equilibria.cpp.o
[ 45%] Building CXX object tests/CMakeFiles/test_orbit.dir/test_orbit.cpp.o
[ 50%] Building CXX object tests/CMakeFiles/test_event.dir/test_event.cpp.o
[ 55%] Building CXX object tests/CMakeFiles/test_invariants.dir/test_invariants.cpp.o
[ 60%] Building CXX object tests/CMakeFiles/test_inertial.dir/test_inertial.cpp.o
[ 65%] Linking CXX executable orbit2d_cli
[ 65%] Built target orbit2d_cli
[ 70%] Linking CXX executable test_field
[ 75%] Linking CXX executable test_symmetry
[ 80%] Linking CXX executable test_inertial
[ 80%] Built target test_field
[ 85%] Linking CXX executable test_event
[ 85%] Built target test_inertial
[ 85%] Built target test_symmetry
[ 90%] Linking CXX executable test_orbit
[ 95%] Linking CXX executable test_invariants
[100%] Linking CXX executable test_equilibria
[100%] Built target test_event
[100%] Built target test_orbit
[100%] Built target test_invariants
[100%] Built target test_equilibria
== Running hidden test suite (ctest) ==
Test project /tmp/tmp.XC5xwq37w0/orbit2d/build_grade
Start 1: test_field
1/7 Test #1: test_field ....................... Passed 0.00 sec
Start 2: test_orbit
2/7 Test #2: test_orbit ....................... Passed 0.01 sec
Start 3: test_symmetry
3/7 Test #3: test_symmetry .................... Passed 0.02 sec
Start 4: test_equilibria
4/7 Test #4: test_equilibria .................. Passed 0.00 sec
Start 5: test_event
5/7 Test #5: test_event ....................... Passed 0.00 sec
Start 6: test_invariants
6/7 Test #6: test_invariants .................. Passed 0.01 sec
Start 7: test_inertial
7/7 Test #7: test_inertial .................... Passed 0.00 sec
100% tests passed, 0 tests failed out of 7
Label Time Summary:
hidden = 0.05 sec*proc (7 tests)
Total Test time (real) = 0.05 sec
PASS: all hidden tests passedReproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_fdbaf6bba4924566. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.
Trial trial_fdbaf6bba4924566 · verifier authoritative; classifier explanatory.