testCases/centralFilmObserver.c

#include <math.h> #include <stdbool.h> #include <stdio.h> #include <string.h>

#include “../src-local/central-film.h”

static int failures;

#define CHECK(condition) do {
if (!(condition)) {
fprintf (stderr, “FAIL %s:%d: %s”, func, LINE, #condition);
failures++;
}
} while (0)

static CentralFilmConfig standard_config (void) { return (CentralFilmConfig) { .advance_window = 1., .minimum_observed_advance = 3., .film_relative_tolerance = 0.02, .front_speed_relative_tolerance = 0.02, .minimum_coverage = 0.8, .maximum_spatial_spread = 0.1, .minimum_fresh_fraction = 0.75, .minimum_cells = 4., .shape_relative_tolerance = 0.02, .hold_windows = 2 }; }

static CentralFilmMeasurement measurement (double time, double front, double film) { return (CentralFilmMeasurement) { .time = time, .front = front, .rear = front - 2., .centroid = front - 1., .film = film, .spatial_spread = 0.01, .coverage = 0.95, .fresh_fraction = 0.9, .minimum_cells = 6. }; }

static bool push (CentralFilmObserver * observer, CentralFilmWindow * window, double time, double front, double film) { CentralFilmMeasurement sample = measurement (time, front, film); return central_film_observer_push (observer, sample, window); }

static void test_quantiles (void) { double odd[] = {9., 1., 5.}; double even[] = {4., 1., 3., 2.}; double quartiles[] = {0., 10., 20., 30., 40.}; CHECK (central_film_median (odd, 3) == 5.); CHECK (central_film_median (even, 4) == 2.5); CHECK (central_film_quantile (quartiles, 5, 0.25) == 10.); CHECK (isnan (central_film_quantile (NULL, 3, 0.5))); CHECK (isnan (central_film_quantile (quartiles, 0, 0.5))); CHECK (isnan (central_film_quantile (quartiles, 5, -0.01))); CHECK (isnan (central_film_quantile (quartiles, 5, 1.01))); CHECK (isnan (central_film_quantile (quartiles, 5, NAN))); CHECK (isnan (central_film_quantile (quartiles, 5, INFINITY))); }

static void test_stable_translating_film_converges (void) { CentralFilmObserver observer; CentralFilmWindow window = {0}; central_film_observer_init (&observer, standard_config());

CHECK (!push (&observer, &window, 0., 0., 0.1)); CHECK (push (&observer, &window, 1., 1., 0.1)); CHECK (window.quality_ok); CHECK (!window.stable); CHECK (!window.film_converged); CHECK (push (&observer, &window, 2., 2., 0.1)); CHECK (!window.stable); CHECK (window.hold_count == 0); CHECK (!window.film_converged); CHECK (push (&observer, &window, 3., 3., 0.1)); CHECK (window.stable); CHECK (window.hold_count == 1); CHECK (!window.film_converged); CHECK (push (&observer, &window, 4., 4., 0.1)); CHECK (window.stable); CHECK (window.hold_count == 2); CHECK (window.film_converged); CHECK (window.shape_steady); }

static void test_reinitialisation_uses_relative_advance (void) { CentralFilmObserver observer; CentralFilmWindow window = {0}; central_film_observer_init (&observer, standard_config());

CHECK (!push (&observer, &window, 1000., 10000., 0.1)); CHECK (!window.film_converged); CHECK (push (&observer, &window, 1001., 10001., 0.1)); CHECK (!window.stable); CHECK (!window.film_converged); CHECK (push (&observer, &window, 1002., 10002., 0.1)); CHECK (!window.film_converged); CHECK (push (&observer, &window, 1003., 10003., 0.1)); CHECK (!window.film_converged); CHECK (push (&observer, &window, 1004., 10004., 0.1)); CHECK (window.film_converged); }

static void check_bad_quality_sample (CentralFilmMeasurement bad) { CentralFilmObserver observer; CentralFilmWindow window = {0}; central_film_observer_init (&observer, standard_config()); CHECK (!central_film_observer_push (&observer, bad, &window)); CHECK (!observer.initialized); CHECK (!observer.have_previous_window); CHECK (observer.hold_count == 0); }

static void test_quality_screens (void) { CentralFilmMeasurement bad = measurement (0., 0., 0.1); bad.fresh_fraction = 0.2; check_bad_quality_sample (bad);

bad = measurement (0., 0., 0.1); bad.coverage = 0.5; check_bad_quality_sample (bad);

bad = measurement (0., 0., 0.1); bad.minimum_cells = 2.; check_bad_quality_sample (bad);

bad = measurement (0., 0., 0.1); bad.spatial_spread = 0.2; check_bad_quality_sample (bad);

bad = measurement (0., 0., 0.); check_bad_quality_sample (bad); }

static void test_bad_quality_breaks_a_hold (void) { CentralFilmObserver observer; CentralFilmWindow window = {0}; CentralFilmConfig config = standard_config(); CentralFilmMeasurement sample; central_film_observer_init (&observer, config);

CHECK (!push (&observer, &window, 0., 0., 0.1)); CHECK (push (&observer, &window, 1., 1., 0.1)); CHECK (push (&observer, &window, 2., 2., 0.1)); CHECK (window.hold_count == 0); CHECK (push (&observer, &window, 3., 3., 0.1)); CHECK (window.hold_count == 1);

sample = measurement (4., 4., 0.1); sample.coverage = 0.5; CHECK (!central_film_observer_push (&observer, sample, &window)); CHECK (!observer.initialized); CHECK (!observer.have_previous_window); CHECK (observer.hold_count == 0); CHECK (!push (&observer, &window, 5., 5., 0.1)); CHECK (push (&observer, &window, 6., 6., 0.1)); CHECK (!window.stable); CHECK (!window.film_converged); }

static void test_drifting_film_is_not_stable (void) { CentralFilmObserver observer; CentralFilmWindow window = {0}; central_film_observer_init (&observer, standard_config()); CHECK (!push (&observer, &window, 0., 0., 0.1)); CHECK (push (&observer, &window, 1., 1., 0.1)); CHECK (push (&observer, &window, 2., 2., 0.2)); CHECK (window.film_drift > observer.config.film_relative_tolerance); CHECK (!window.stable); CHECK (!window.film_converged); }

static void test_changing_front_speed_is_not_stable (void) { CentralFilmObserver observer; CentralFilmWindow window = {0}; central_film_observer_init (&observer, standard_config()); CHECK (!push (&observer, &window, 0., 0., 0.1)); CHECK (push (&observer, &window, 1., 1., 0.1)); CHECK (push (&observer, &window, 3., 2., 0.1)); CHECK (window.front_speed_drift > observer.config.front_speed_relative_tolerance); CHECK (!window.stable); CHECK (!window.film_converged); }

static void test_film_and_shape_milestones_are_distinct (void) { CentralFilmObserver observer; CentralFilmWindow window = {0}; central_film_observer_init (&observer, standard_config());

for (int i = 0; i <= 4; i++) { CentralFilmMeasurement sample = measurement ((double) i, (double) i, 0.1); sample.rear = -2. + 0.5i; sample.centroid = -1. + 0.8i; bool completed = central_film_observer_push (&observer, sample, &window); CHECK (completed == (i > 0)); } CHECK (window.film_converged); CHECK (!window.shape_steady); CHECK (!window.shape_converged); }

static void test_shape_convergence_needs_consecutive_windows (void) { CentralFilmObserver observer; CentralFilmWindow window = {0}; central_film_observer_init (&observer, standard_config());

for (int i = 0; i <= 4; i++) { CentralFilmMeasurement sample = measurement ((double) i, (double) i, 0.1); sample.rear = -2. + 0.5i; sample.centroid = -1. + 0.8i; (void) central_film_observer_push (&observer, sample, &window); } CHECK (window.film_converged); CHECK (!window.shape_steady);

CentralFilmMeasurement steady = measurement (5., 5., 0.1); steady.rear = 1.; steady.centroid = 3.2; CHECK (central_film_observer_push (&observer, steady, &window)); CHECK (window.film_converged); CHECK (window.shape_steady); CHECK (window.shape_hold_count == 1); CHECK (!window.shape_converged);

steady = measurement (6., 6., 0.1); steady.rear = 2.; steady.centroid = 4.2; CHECK (central_film_observer_push (&observer, steady, &window)); CHECK (window.shape_steady); CHECK (window.shape_hold_count == 2); CHECK (window.shape_converged); }

static void assert_discontinuity_restarts_observation (CentralFilmMeasurement discontinuity, bool discontinuity_is_new_anchor) { CentralFilmObserver observer; CentralFilmWindow window = {0}; central_film_observer_init (&observer, standard_config()); CHECK (!push (&observer, &window, 0., 0., 0.1)); CHECK (push (&observer, &window, 1., 1., 0.1)); CHECK (push (&observer, &window, 2., 2., 0.1)); CHECK (window.hold_count == 0); CHECK (push (&observer, &window, 3., 3., 0.1)); CHECK (window.hold_count == 1);

CHECK (!central_film_observer_push (&observer, discontinuity, &window));

/* A bad observation breaks continuity. The next valid sample is a new anchor and cannot close a window using history from before the gap.

CHECK (push (&observer, &window, 20., 20., 0.1) == discontinuity_is_new_anchor); if (!discontinuity_is_new_anchor) CHECK (push (&observer, &window, 21., 21., 0.1)); CHECK (!window.stable); CHECK (window.hold_count == 0); CHECK (!window.film_converged); } static void test_nonfinite_sample_breaks_history (void) { CentralFilmMeasurement bad = measurement (3., 3., 0.1); bad.film = NAN; assert_discontinuity_restarts_observation (bad, false); bad = measurement (3., 3., 0.1); bad.front = INFINITY; assert_discontinuity_restarts_observation (bad, false); } static void test_nonmonotonic_time_breaks_history (void) { CentralFilmMeasurement bad = measurement (1.5, 3., 0.1); assert_discontinuity_restarts_observation (bad, true); bad = measurement (3., 4., 0.1); assert_discontinuity_restarts_observation (bad, true); } static void test_nonmonotonic_front_breaks_history (void) { CentralFilmMeasurement bad = measurement (3., 1.5, 0.1); assert_discontinuity_restarts_observation (bad, true); bad = measurement (4., 3., 0.1); assert_discontinuity_restarts_observation (bad, true); } static void test_null_arguments_are_rejected (void) { CentralFilmObserver observer; CentralFilmWindow window = {0}; CentralFilmMeasurement sample = measurement (0., 0., 0.1); central_film_observer_init (&observer, standard_config()); CHECK (!central_film_observer_push (NULL, sample, &window)); CHECK (!central_film_observer_push (&observer, sample, NULL)); } int main (void) { test_quantiles(); test_stable_translating_film_converges(); test_reinitialisation_uses_relative_advance(); test_quality_screens(); test_bad_quality_breaks_a_hold(); test_drifting_film_is_not_stable(); test_changing_front_speed_is_not_stable(); test_film_and_shape_milestones_are_distinct(); test_shape_convergence_needs_consecutive_windows(); test_nonfinite_sample_breaks_history(); test_nonmonotonic_time_breaks_history(); test_nonmonotonic_front_breaks_history(); test_null_arguments_are_rejected(); if (failures) { fprintf (stderr, “central-film observer: %d assertion(s) failed”, failures); return 1; } puts (“central-film observer: PASS”); return 0; }