first draft

course2/sem3/labs/lab3.01/scripts/4.py

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+from collections import defaultdict
+from sys import argv
+
+import matplotlib.pyplot as plt
+import numpy as np
+
+
+def read_points(filename: str) -> list[tuple[float, float, str]]:
+    points = []
+    with open(filename, "r", encoding="utf-8") as f:
+        for line in f:
+            line = line.strip()
+            if line and not line.startswith("#"):
+                parts = line.split()
+                if len(parts) >= 3:
+                    x = float(parts[0])
+                    y = float(parts[1])
+                    label = parts[2]
+                    points.append((x, y, label))
+    return points
+
+
+def main() -> None:
+    points = read_points(argv[1])
+
+    plt.figure(figsize=(8.27, 11.69))
+    plt.xlim(0, 30)
+    plt.ylim(0, 20)
+    plt.gca().set_aspect("equal", adjustable="box")
+    plt.grid(True, linewidth=0.3)
+    plt.xticks(range(0, 31, 2))
+    plt.yticks(range(0, 21, 2))
+
+    grouped = defaultdict(list)
+    for x, y, phi in points:
+        grouped[phi].append((x, y))
+
+    for x, y, label in points:
+        plt.scatter(x, y, color="red", s=15)
+        plt.text(x + 0.3, y + 0.3, label, fontsize=9)
+
+    for phi, coords in grouped.items():
+        coords.sort(key=lambda p: p[1])
+        xs, ys = zip(*coords)
+        plt.plot(xs, ys, linewidth=0.8, label=f"φ={phi} В")
+
+    if int(argv[2]):
+        theta = np.linspace(0, 2 * np.pi, 200)
+        cx, cy = 15, 9
+
+        for r in [5, 6]:
+            x = cx + r * np.cos(theta)
+            y = cy + r * np.sin(theta)
+            plt.plot(x, y, color="blue", linewidth=1)
+
+    emax_x, emax_y = 22.4, 10
+    emin_x, emin_y = 15, 9
+
+    plt.arrow(
+        emax_x + 2,
+        emax_y + 2,
+        -1.5,
+        -1.2,
+        head_width=0.4,
+        head_length=0.3,
+        fc="darkgreen",
+        ec="darkgreen",
+        linewidth=2,
+    )
+    plt.text(emax_x + 2.3, emax_y + 2.3, "E_max", fontsize=11, color="darkgreen")
+
+    plt.arrow(
+        emin_x - 3,
+        emin_y + 3,
+        1.5,
+        -1.5,
+        head_width=0.4,
+        head_length=0.3,
+        fc="darkgreen",
+        ec="darkgreen",
+        linewidth=2,
+    )
+    plt.text(emin_x - 4.2, emin_y + 3.2, "E_min", fontsize=11, color="darkgreen")
+
+    plt.xlabel("X (см)")
+    plt.ylabel("Y (см)")
+    plt.title("Эквипотенциальные линии")
+    plt.savefig("points.png", dpi=300)
+
+
+if __name__ == "__main__":
+    main()

course2/sem3/labs/lab3.01/scripts/5.py

@@ -0,0 +1,55 @@
+from pathlib import Path
+from typing import List, Tuple
+
+import matplotlib.pyplot as plt
+
+
+def read_points(filename: str) -> List[Tuple[float, float, float]]:
+    pts = []
+    for line in Path(filename).read_text(encoding="utf-8").splitlines():
+        line = line.strip()
+        if not line or line.startswith("#"):
+            continue
+        parts = line.split()
+        if len(parts) < 3:
+            continue
+        x = float(parts[0])
+        y = float(parts[1])
+        phi = float(parts[2])
+        pts.append((x, y, phi))
+    return pts
+
+
+def phi_vs_x_at_y(
+    points: List[Tuple[float, float, float]], y_target: float, tol: float = 1e-6
+):
+    xs = []
+    phis = []
+    for x, y, phi in points:
+        if abs(y - y_target) <= tol:
+            xs.append(x)
+            phis.append(phi)
+    paired = sorted(zip(xs, phis), key=lambda p: p[0])
+    if not paired:
+        return [], []
+    xs_sorted, phis_sorted = zip(*paired)
+    return list(xs_sorted), list(phis_sorted)
+
+
+p1 = read_points("points1.txt")
+p2 = read_points("points2.txt")
+
+x1, yphi1 = phi_vs_x_at_y(p1, 10.0)
+x2, yphi2 = phi_vs_x_at_y(p2, 10.0)
+
+plt.figure(figsize=(10, 5))
+if x1:
+    plt.plot(x1, yphi1, marker="o", linestyle="-", label="points1.txt (Y=10)")
+if x2:
+    plt.plot(x2, yphi2, marker="s", linestyle="--", label="points2.txt (Y=10)")
+plt.xlabel("X (см)")
+plt.ylabel("φ (В)")
+plt.title("Зависимость φ = φ(X) при Y = 10 см")
+plt.grid(alpha=0.4)
+plt.legend()
+plt.savefig("phi_vs_x_Y10.png", dpi=300)