Method of solving systems of differential equations

numeric_lab5/euler-method.py

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+from math import sin, pi
+import matplotlib.pylab as plt
+
+U_max = 100
+frequency = 50
+R1 = 5
+R2 = 4
+R3 = 7
+R4 = 2
+L1 = 0.01
+L2 = 0.02
+C1 = 300 * 10 ** -6
+h = 0.00001
+
+
+f = [lambda cur_time, value: (value[1]/C1),
+     lambda cur_time, value: (U_max * sin(2 * pi * frequency * cur_time) - value[0] - value[1]*R1 + value[2]*R2)/L1,
+     lambda cur_time, value: (value[1]*R1 - value[2]*R1 - value[2]*R2)/L2]
+
+
+def output_voltage(value):
+    print(value[2] * R2)
+    return value[2] * R2
+
+
+def get_next_value(current_time, value, h):
+    next_value = value
+    for i in range(len(value)):
+        next_value[i] = value[i] + h * f[i](current_time, value)
+    return next_value
+
+
+def get_results(current_time, end_time, value, h):
+    time_value = dict()
+    while current_time < end_time:
+        next_cur_time = current_time + h
+        next_value = get_next_value(current_time, value, h)
+        current_time = next_cur_time
+        value = next_value
+        time_value[current_time] = output_voltage(value)
+    return time_value
+
+
+def main():
+    start_time = 0
+    end_time = 0.2
+    init_values = [0, 0, 0]
+
+    result = get_results(start_time, end_time, init_values, h)
+
+    results_for_each_value = []
+    values = []
+
+    for t, v in result.items():
+        results_for_each_value.append(t)
+        values.append(v)
+
+    plt.plot(results_for_each_value, values)
+    plt.show()
+
+
+if __name__ == '__main__':
+    main()