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| 1 | +# -*- coding: utf-8 -*- |
| 2 | + |
| 3 | + |
| 4 | +import unittest |
| 5 | + |
| 6 | +import brainpy as bp |
| 7 | +import brainpy.math as bm |
| 8 | + |
| 9 | + |
| 10 | +class TestExplicitRKStateDelay(unittest.TestCase): |
| 11 | + def test_euler(self): |
| 12 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 13 | + |
| 14 | + @bp.ddeint(method='euler', state_delays={'x': xdelay}) |
| 15 | + def equation(x, t, ): |
| 16 | + return -xdelay(t - 1) |
| 17 | + |
| 18 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 19 | + runner.run(20.) |
| 20 | + |
| 21 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 22 | + |
| 23 | + def test_midpoint(self): |
| 24 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 25 | + |
| 26 | + @bp.ddeint(method='midpoint', state_delays={'x': xdelay}) |
| 27 | + def equation(x, t, ): |
| 28 | + return -xdelay(t - 1) |
| 29 | + |
| 30 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 31 | + runner.run(20.) |
| 32 | + |
| 33 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 34 | + |
| 35 | + def test_heun2(self): |
| 36 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 37 | + |
| 38 | + @bp.ddeint(method='heun2', state_delays={'x': xdelay}) |
| 39 | + def equation(x, t, ): |
| 40 | + return -xdelay(t - 1) |
| 41 | + |
| 42 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 43 | + runner.run(20.) |
| 44 | + |
| 45 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 46 | + |
| 47 | + def test_ralston2(self): |
| 48 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 49 | + |
| 50 | + @bp.ddeint(method='ralston2', state_delays={'x': xdelay}) |
| 51 | + def equation(x, t, ): |
| 52 | + return -xdelay(t - 1) |
| 53 | + |
| 54 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 55 | + runner.run(20.) |
| 56 | + |
| 57 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 58 | + |
| 59 | + def test_rk2(self): |
| 60 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 61 | + |
| 62 | + @bp.ddeint(method='rk2', |
| 63 | + state_delays={'x': xdelay}) |
| 64 | + def equation(x, t, ): |
| 65 | + return -xdelay(t - 1) |
| 66 | + |
| 67 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 68 | + runner.run(20.) |
| 69 | + |
| 70 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 71 | + |
| 72 | + def test_rk3(self): |
| 73 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 74 | + |
| 75 | + @bp.ddeint(method='rk3', state_delays={'x': xdelay}) |
| 76 | + def equation(x, t, ): |
| 77 | + return -xdelay(t - 1) |
| 78 | + |
| 79 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 80 | + runner.run(20.) |
| 81 | + |
| 82 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 83 | + |
| 84 | + def test_heun3(self): |
| 85 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 86 | + |
| 87 | + @bp.ddeint(method='heun3', state_delays={'x': xdelay}) |
| 88 | + def equation(x, t, ): |
| 89 | + return -xdelay(t - 1) |
| 90 | + |
| 91 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 92 | + runner.run(20.) |
| 93 | + |
| 94 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 95 | + |
| 96 | + def test_ralston3(self): |
| 97 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 98 | + |
| 99 | + @bp.ddeint(method='ralston3', state_delays={'x': xdelay}) |
| 100 | + def equation(x, t, ): |
| 101 | + return -xdelay(t - 1) |
| 102 | + |
| 103 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 104 | + runner.run(20.) |
| 105 | + |
| 106 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 107 | + |
| 108 | + def test_ssprk3(self): |
| 109 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 110 | + |
| 111 | + @bp.ddeint(method='ssprk3', state_delays={'x': xdelay}) |
| 112 | + def equation(x, t, ): |
| 113 | + return -xdelay(t - 1) |
| 114 | + |
| 115 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 116 | + runner.run(20.) |
| 117 | + |
| 118 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 119 | + |
| 120 | + def test_rk4(self): |
| 121 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 122 | + |
| 123 | + @bp.ddeint(method='rk4', state_delays={'x': xdelay}) |
| 124 | + def equation(x, t, ): |
| 125 | + return -xdelay(t - 1) |
| 126 | + |
| 127 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 128 | + runner.run(20.) |
| 129 | + |
| 130 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 131 | + |
| 132 | + def test_ralston4(self): |
| 133 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 134 | + |
| 135 | + @bp.ddeint(method='ralston4', state_delays={'x': xdelay}) |
| 136 | + def equation(x, t, ): |
| 137 | + return -xdelay(t - 1) |
| 138 | + |
| 139 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 140 | + runner.run(20.) |
| 141 | + |
| 142 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 143 | + |
| 144 | + def test_rk4_38rule(self): |
| 145 | + xdelay = bm.TimeDelay(bm.zeros((1,)), 1., before_t0=-1., interp_method='round') |
| 146 | + |
| 147 | + @bp.ddeint(method='rk4_38rule', state_delays={'x': xdelay}) |
| 148 | + def equation(x, t, ): |
| 149 | + return -xdelay(t - 1) |
| 150 | + |
| 151 | + runner = bp.integrators.IntegratorRunner(equation, monitors=['x']) |
| 152 | + runner.run(20.) |
| 153 | + |
| 154 | + bp.visualize.line_plot(runner.mon.ts, runner.mon['x'], show=True) |
| 155 | + |
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