🐛 fix ε accuracy

tests/test_word_problem.py

@@ -0,0 +1,43 @@
+# -*- coding: utf-8 -*-
+"""
+应用题测试集
+"""
+import logging
+
+from mbcp.mp_math.line import Line3
+from mbcp.mp_math.plane import Plane3
+from mbcp.mp_math.point import Point3
+
+
+class TestWordProblem:
+
+    def test_c8s4e4(self):
+        """
+        同济大学《高等数学》第八版 下册 第八章第四节例4
+        问题：求与两平面x-4z-3=0和2x-y-5z-1=0的交线平行且过点(-3, 2, 5)的直线方程。
+        """
+        correct_ans = Line3(4, 3, 1, 1)
+
+        pl1 = Plane3(1, 0, -4, -3)
+        pl2 = Plane3(2, -1, -5, -1)
+        p = Point3(-3, 2, 5)
+        """解法1"""
+        # 求直线方向向量s
+        s = pl1.normal @ pl2.normal
+        actual_ans = Line3.from_point_and_direction(p, s)
+
+        logging.info(f"正确答案：{correct_ans}    实际答案：{actual_ans}")
+        assert actual_ans == correct_ans
+
+        """解法2"""
+        # 过点p且与pl1平行的平面pl3
+        pl3 = pl1.cal_parallel_plane3(p)
+        # 过点p且与pl2平行的平面pl4
+        pl4 = pl2.cal_parallel_plane3(p)
+        # 求pl3和pl4的交线
+        actual_ans = pl3.cal_intersection_line3(pl4)
+        print(pl3, pl4, actual_ans)
+
+        logging.info(f"正确答案：{correct_ans}    实际答案：{actual_ans}")
+        assert actual_ans == correct_ans
+