excel happened

Л3-В6/Программа/example.txt

@@ -20,3 +20,12 @@
 23.4 -14.2 -5.4 2.1 6.6
 6.3 -13.2 -6.5 14.3 9.4
 5.6 8.8 -6.7 -23.8 7.3
+
+# some textbook
+100 11 0 4 -5 -4 -6 11
+13 200 -2 -2 -4 -2 -1 18
+-7 1 5 12 -4 -5 3 -18
+-5 16 4 -1 0 -3 17 -4
+22 -9 -3 2 300 0 -8 -21
+-5 -3 15 3 15 4 16 -1
+0 -2 -11 -2 -2 10 -150 -6

Л3-В6/Программа/src/solution.py

@@ -4,7 +4,7 @@ import numpy as np
 
 
 def iterative_method(
-    A: np.matrix, B: np.matrix, eps: float = 0.0001, max_iterations: int = 10000
+    A: np.matrix, B: np.matrix, eps: float = 0.0001, max_iterations: int = 100_000
 ) -> np.matrix:
     if A.shape[0] != A.shape[1] or A.shape[0] != B.shape[0] or B.shape[1] != 1:
         return None
@@ -25,6 +25,11 @@ def iterative_method(
 
         swaps.extend(swaps_)
 
+    _make_diagonal_dominant(alpha, beta)
+
+    if algorithm.det(alpha) == 0:
+        return None
+
     for i in range(n):
         beta[i, 0] = beta[i, 0] / alpha[i, i]
 
@@ -37,9 +42,6 @@ def iterative_method(
 
         alpha[i, i] = 0
 
-    if algorithm.norm(alpha) >= 1.0:
-        return None
-
     i = 0
     X = np.copy(beta)
     while i < max_iterations:
@@ -51,12 +53,46 @@ def iterative_method(
         if np.sum(np.abs(X - X_old)) < eps:
             break
 
+    print(f"iterations: {i}")
+
     for i, j in swaps:
         X[[i, j], :] = X[[j, i], :]
 
     return X
 
 
+# WTF EVEN IS THIS
+# EXCEL MOMENT: https://elib.bsu.by/bitstream/123456789/52531/1/42-47.pdf
+def _make_diagonal_dominant(a: np.matrix, b: np.matrix):
+    n = a.shape[0]
+    a_inv = np.linalg.inv(a.T)
+
+    do_changes = [0] * n
+    for i in range(n):
+        if np.sum(np.abs(a[i, :])) > 2 * np.abs(a[i, i]):
+            do_changes[i] = 1
+
+    helper = np.ones((n, n))
+    for i in range(n):
+        helper[i, i] = 2 * n
+
+    koef = np.zeros((n, n))
+    for i in range(n):
+        for j in range(n):
+            if not do_changes[j]:
+                continue
+            koef[i, j] = np.sum(a_inv[i, :] * helper[:, j]) * b[i, 0]
+
+    koef_sum = np.sum(koef, axis=0)
+
+    for i in range(n):
+        if not do_changes[i]:
+            continue
+        a[i, :] = np.ones(n)
+        a[i, i] = 2 * n
+        b[i, 0] = koef_sum[i]
+
+
 def _swap_rows(a: np.matrix, b: np.matrix) -> bool:
     n = a.shape[0]
     for i in range(n):

Л3-В6/Программа/src/window.py

@@ -220,6 +220,8 @@ class MainWindow(QMainWindow):
 
     def setupUI(self):
         self.setWindowTitle("Лабораторная работа №3")
+        self.resize(700, 200)
+
         self.central_widget = QWidget()
         self.setCentralWidget(self.central_widget)
 
@@ -244,6 +246,10 @@ class MainWindow(QMainWindow):
         self.paste_button.clicked.connect(self.on_paste_button_clicked)
         buttons_row_layout.addWidget(self.paste_button)
 
+        self.random_button = QPushButton("Случайная", self)
+        self.random_button.clicked.connect(self.on_random_button_clicked)
+        buttons_row_layout.addWidget(self.random_button)
+
         buttons_row.setLayout(buttons_row_layout)
         layout.addWidget(buttons_row)
 
@@ -268,6 +274,13 @@ class MainWindow(QMainWindow):
 
         self.central_widget.setLayout(layout)
 
+    def on_random_button_clicked(self):
+        n = int(self.n_input.get_value())
+        self.matrix_a = np.round(np.random.rand(n, n) * 10, 2)
+        self.matrix_b = np.round(np.random.rand(n, 1) * 10, 2)
+
+        self.set_matrix(self.matrix_a, self.matrix_b)
+
     def on_find_solution_clicked(self):
         x = solution.iterative_method(self.matrix_a, self.matrix_b)
 
@@ -368,9 +381,12 @@ class MainWindow(QMainWindow):
 
         try:
             self.det_display.set_text(f"{algorithm.det(self.matrix_a):.5f}")
-            self.cond_display.set_text(f"{algorithm.cond(self.matrix_a):.5f}")
         except:
             self.det_display.set_text("Невозможно вычислить")
+
+        try:
+            self.cond_display.set_text(f"{algorithm.cond(self.matrix_a):.5f}")
+        except:
             self.cond_display.set_text("Невозможно вычислить")
 
     def set_matrix(self, A: np.matrix, B: np.matrix):