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Diffstat (limited to 'tests/test_migration.py')
| -rw-r--r-- | tests/test_migration.py | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/tests/test_migration.py b/tests/test_migration.py new file mode 100644 index 0000000..160f75a --- /dev/null +++ b/tests/test_migration.py @@ -0,0 +1,200 @@ +import unittest + +import numpy as np + +from tests.helpers import line_world, make_history, make_race +from worldhistory.migration import drift_and_bud, long_jumps, travel_cost +from worldhistory.config import CONDITIONS +from worldhistory.state import new_state + +D_DEPTH = CONDITIONS.index("depth") + +MP = make_history().migration + + +def setup(n, pop, race, K=1e6): + st = new_state(1, n, np.zeros((1, 6)), seed=0) + st.P[0, 0] = pop + return st, np.full((1, n), K), np.ones((1, n), bool) + + +class MigrationTest(unittest.TestCase): + def test_travel_cost(self): + w = line_world(4, ocean=[False, False, False, True], landform=[1, 3, 1, 0], river=[True, False, False, False], + holdridge=[20, 20, 23, 0]) + r = make_race(travel={"mountain": 2.0, "desert": 1.0}) + np.testing.assert_allclose(travel_cost(w, r, np.zeros(4)), [-1, 2, 0, 0]) # cell 2: desert +1, coast -1 + np.testing.assert_allclose(travel_cost(w, r, np.full(4, 0.5)), [-1.5, 1.5, -0.5, -0.5]) + + def test_budding_needs_founder_group(self): + w = line_world(3) + r = make_race(demography={"founder": 50.0, "mobility": 0.1}) + st, K, OK = setup(3, 60.0, r, K=100.0) # crowded, but below 2 founders + drift_and_bud(st, w, [r], K, OK, np.zeros((1, 3)), np.zeros((1, 3)), np.ones((1, 3)), + np.random.default_rng(0), MP) + self.assertEqual(float(st.P[0, 1]), 0.0) + st, K, OK = setup(3, 120.0, r, K=100.0) + drift_and_bud(st, w, [r], K, OK, np.zeros((1, 3)), np.zeros((1, 3)), np.ones((1, 3)), + np.random.default_rng(0), MP) + self.assertIn(float(st.P[0, 1]), (0.0, 20.0)) # a founder group (capped at P/6 = 20) or nothing + self.assertAlmostEqual(float(st.P[0].sum()), 120.0) + + def test_river_colonised_before_mountain(self): + r = make_race(demography={"founder": 5.0, "mobility": 0.1}, travel={"mountain": 2.0}) + hits = {0: 0, 2: 0} + for seed in range(60): + st = new_state(1, 3, np.zeros((1, 6)), seed=0) + st.P[0, 1] = 100.0 + w2 = line_world(3, landform=[1, 1, 3], river=[True, True, False]) # cell 0 river plain, cell 2 mountain + tc = travel_cost(w2, r, np.zeros(3))[None] + drift_and_bud(st, w2, [r], np.full((1, 3), 100.0), np.ones((1, 3), bool), tc, np.zeros((1, 3)), + np.ones((1, 3)), np.random.default_rng(seed), MP) + hits[0] += st.P[0, 0] > 0 + hits[2] += st.P[0, 2] > 0 + self.assertGreater(hits[0], hits[2]) + + def test_drift_toward_headroom(self): + w = line_world(3) + r = make_race(demography={"mobility": 0.2}) + st = new_state(1, 3, np.zeros((1, 6)), seed=0) + st.P[0] = [100.0, 100.0, 100.0] + K = np.array([[1000.0, 1000.0, 5000.0]]) + drift_and_bud(st, w, [r], K, np.ones((1, 3), bool), np.zeros((1, 3)), np.zeros((1, 3)), + np.ones((1, 3)), np.random.default_rng(0), MP) + self.assertGreater(float(st.P[0, 2]), float(st.P[0, 0])) # cell 1 sends more toward the roomier side + self.assertAlmostEqual(float(st.P[0].sum()), 300.0) + + def test_never_into_uninhabitable(self): + w = line_world(3) + r = make_race(demography={"mobility": 0.2, "founder": 1.0}) + st = new_state(1, 3, np.zeros((1, 6)), seed=0) + st.P[0] = [0.0, 100.0, 100.0] + drift_and_bud(st, w, [r], np.full((1, 3), 100.0), np.array([[False, True, True]]), np.zeros((1, 3)), + np.zeros((1, 3)), np.ones((1, 3)), np.random.default_rng(0), MP) + self.assertEqual(float(st.P[0, 0]), 0.0) + self.assertAlmostEqual(float(st.P[0].sum()), 200.0) + + def test_drift_keeps_viable_source_viable(self): + # uncrowded viable group (22, Allee 20) beside a small one: drift may not take it below the Allee threshold + w = line_world(2) + r = make_race(demography={"mobility": 0.5, "allee": 20.0, "founder": 20.0}) + st = new_state(1, 2, np.zeros((1, 6)), seed=0) + st.P[0] = [22.0, 5.0] + drift_and_bud(st, w, [r], np.full((1, 2), 1e5), np.ones((1, 2), bool), np.zeros((1, 2)), + np.zeros((1, 2)), np.ones((1, 2)), np.random.default_rng(0), MP) + self.assertGreaterEqual(float(st.P[0, 0]), 20.0) + self.assertAlmostEqual(float(st.P[0].sum()), 27.0) + + def test_small_group_joins_viable_neighbour(self): + # below the Allee threshold, a group gathers into its viable neighbour rather than dwindling alone + w = line_world(3) + r = make_race(demography={"mobility": 0.1, "allee": 20.0, "founder": 20.0}) + st = new_state(1, 3, np.zeros((1, 6)), seed=0) + st.P[0] = [8.0, 30.0, 0.0] + drift_and_bud(st, w, [r], np.full((1, 3), 1e5), np.ones((1, 3), bool), np.zeros((1, 3)), + np.zeros((1, 3)), np.ones((1, 3)), np.random.default_rng(0), MP) + np.testing.assert_allclose(st.P[0], [0.0, 38.0, 0.0]) + + def test_push_flees_into_empty_land(self): + # people driven out (push) settle an empty livable neighbour even when nobody is crowded + w = line_world(2) + r = make_race(demography={"mobility": 0.0, "allee": 20.0, "founder": 20.0}) + st = new_state(1, 2, np.zeros((1, 6)), seed=0) + st.P[0] = [120.0, 0.0] + st.push[0, 0] = 30.0 + drift_and_bud(st, w, [r], np.full((1, 2), 1e5), np.ones((1, 2), bool), np.zeros((1, 2)), + np.zeros((1, 2)), np.ones((1, 2)), np.random.default_rng(0), MP) + np.testing.assert_allclose(st.P[0], [100.0, 20.0]) # capped at P/6 per neighbour + + def test_roaming_groups_travel_together(self): + # roam = chance per step that a whole group (a caravan) moves on, together, to one neighbouring cell + w = line_world(3) + r = make_race(demography={"mobility": 0.0, "allee": 2.0, "founder": 2.0, "roam": 1.0}) + ends = set() + for seed in range(20): + st = new_state(1, 3, np.zeros((1, 6)), seed=0) + st.P[0] = [0.0, 120.0, 0.0] + drift_and_bud(st, w, [r], np.full((1, 3), 1e5), np.ones((1, 3), bool), np.zeros((1, 3)), + np.zeros((1, 3)), np.ones((1, 3)), np.random.default_rng(seed), MP) + self.assertEqual(float(st.P[0, 1]), 0.0) + self.assertIn(float(st.P[0].max()), (120.0,)) + ends.add(int(st.P[0].argmax())) + self.assertEqual(ends, {0, 2}) # either way, never split + + def test_long_jump_crosses_chasm_on_migrants_adaptation(self): + # deep-adapted swimmers skip an abyss they cannot live in and land on ground that suits *them*, even though + # the landing cells' stored optimum (native, 0 m) would call them unfit + from worldhistory.habitat import environment, suitability + depth = np.r_[np.full(5, 2000.0), np.full(35, 6000.0), np.full(40, 2000.0)] + w = line_world(80, spacing_km=10.0, ocean=True, elevation_m=-depth) + tol = {"depth": {"optimum": 0, "width": 60, "lo": 0, "hi": 7000, "rate": 2.0}} + r = make_race(demography={"founder": 2.0, "allee": 1.0, "jump": 1.0}, tolerance=tol, + habitat={"realm": "sea", "terms": [{"p": "sea", "w": 1.0}]}) + env, suit = environment(w), suitability(w, r)[None] + landed = set() + for seed in range(200): + st = new_state(1, w.n, np.zeros((1, 6)), seed=0) + st.P[0, 0] = 1e6 + st.O[0, D_DEPTH, :5] = 2000.0 + long_jumps(st, w, [r], np.full((1, w.n), 1e6), np.ones((1, w.n), bool), np.random.default_rng(seed), + {**MP, "jump_rate": 1.0}, np.ones((1, w.n)), env=env, suit=suit, f_min=0.1) + landed |= set(np.flatnonzero(st.P[0, 1:] > 0) + 1) + self.assertTrue(any(c >= 40 for c in landed)) # across the chasm + self.assertFalse(any(5 <= c < 40 for c in landed)) # never into the abyss + + def test_sea_path_jumps_never_cross_land(self): + # swimmers (jump_path = sea) cannot hop over a strip of land; without it they can + ocean = np.r_[np.ones(5, bool), np.zeros(5, bool), np.ones(70, bool)] + w = line_world(80, spacing_km=10.0, ocean=ocean, elevation_m=np.where(ocean, -100.0, 10.0)) + from worldhistory.habitat import environment, suitability + for path, beyond in (("any", True), ("sea", False)): + r = make_race(demography={"founder": 2.0, "allee": 1.0, "jump_path": path}, + habitat={"realm": "sea", "terms": [{"p": "sea", "w": 1.0}]}) + env, suit = environment(w), suitability(w, r)[None] + landed = set() + for seed in range(200): + st = new_state(1, w.n, np.zeros((1, 6)), seed=0) + st.P[0, 0] = 1e6 + long_jumps(st, w, [r], np.full((1, w.n), 1e6), np.ones((1, w.n), bool), np.random.default_rng(seed), + {**MP, "jump_rate": 1.0}, np.ones((1, w.n)), env=env, suit=suit, f_min=0.1) + landed |= set(np.flatnonzero(st.P[0, 1:] > 0) + 1) + self.assertEqual(any(c >= 10 for c in landed), beyond, path) + + def test_large_group_splits(self): + # clans above group_max break up: half leaves as a new group into empty land + w = line_world(3) + r = make_race(demography={"mobility": 0.0, "allee": 20.0, "founder": 20.0, "group_max": 500.0}) + st = new_state(1, 3, np.zeros((1, 6)), seed=0) + st.P[0] = [0.0, 1200.0, 0.0] + drift_and_bud(st, w, [r], np.full((1, 3), 1e5), np.ones((1, 3), bool), np.zeros((1, 3)), + np.zeros((1, 3)), np.ones((1, 3)), np.random.default_rng(0), MP) + np.testing.assert_allclose(st.P[0], [200.0, 800.0, 200.0]) # 600 leave, capped P/6 per side + + def test_push_leaves(self): + w = line_world(2) + r = make_race(demography={"mobility": 0.0}) + st = new_state(1, 2, np.zeros((1, 6)), seed=0) + st.P[0] = [100.0, 100.0] + st.push[0, 0] = 10.0 + drift_and_bud(st, w, [r], np.full((1, 2), 1000.0), np.ones((1, 2), bool), np.zeros((1, 2)), + np.zeros((1, 2)), np.ones((1, 2)), np.random.default_rng(0), MP) + np.testing.assert_allclose(st.P[0], [90.0, 110.0]) + self.assertEqual(float(st.push.sum()), 0.0) + + def test_long_jump_distances(self): + w = line_world(4000, spacing_km=10.0) + r = make_race(demography={"founder": 2.0, "allee": 1.0}) + st = new_state(1, w.n, np.zeros((1, 6)), seed=0) + st.P[0, 0] = 1e6 + d = [] + for seed in range(300): + st.P[0] = 0 + st.P[0, 0] = 1e6 + long_jumps(st, w, [r], np.full((1, w.n), 1e6), np.ones((1, w.n), bool), np.random.default_rng(seed), + {**MP, "jump_rate": 1.0}, np.ones((1, w.n))) + hit = np.flatnonzero(st.P[0, 1:]) + 1 + d += list(np.minimum(hit, w.n - hit) * 10.0) # the line circles the globe: wrap + d = np.array(d) + self.assertGreater(len(d), 100) # a line world: only jumps along the line land near it + self.assertTrue((d <= MP["jump_cap_km"] + 10).all()) + self.assertGreater(float(np.median(d)), MP["jump_xm_km"] * 0.8) |