fix(ms): 🐛 fix idz#8

4 матстат/идз/lab8/matrix.py

@@ -0,0 +1,69 @@
+def calc_det2(A):
+    return A[0][0] * A[1][1] - A[0][1] * A[1][0]
+
+def solve2(A, B):
+    n = 2
+    det = calc_det2(A)
+    det1 = calc_det2([[B[r], A[r][1]] for r in range(n)])
+    det2 = calc_det2([[A[r][0], B[r]] for r in range(n)])
+    x1 = det1 / det
+    x2 = det2 / det
+    return x1, x2
+
+
+def calc_det3(A):
+    pos = A[0][0] * A[1][1] * A[2][2] + \
+          A[0][1] * A[1][2] * A[2][0] + \
+          A[0][2] * A[1][0] * A[2][1]
+    neg = A[0][2] * A[1][1] * A[2][0] + \
+          A[0][1] * A[1][0] * A[2][2] + \
+          A[0][0] * A[1][2] * A[2][1]
+    return pos - neg
+
+def solve3(A, B):
+    n = 3
+    det = calc_det3(A)
+    det1 = calc_det3([[B[r], A[r][1], A[r][2]] for r in range(n)])
+    det2 = calc_det3([[A[r][0], B[r], A[r][2]] for r in range(n)])
+    det3 = calc_det3([[A[r][0], A[r][1], B[r]] for r in range(n)])
+    x1 = det1 / det
+    x2 = det2 / det
+    x3 = det3 / det
+    return x1, x2, x3
+
+
+def calc_det4(A):
+    n = 4
+    sign = 1
+    r = 0
+    res = 0
+    for c in range(n):
+        A_ = [[A[r_][c_] for c_ in range(n) if c_ != c]
+              for r_ in range(n) if r_ != r]
+        res += sign * A[r][c] * calc_det3(A_)
+        sign *= -1
+    return res
+
+def solve4(A, B):
+    n = 4
+    det = calc_det4(A)
+    det1 = calc_det4([[B[r], A[r][1], A[r][2], A[r][3]] for r in range(n)])
+    det2 = calc_det4([[A[r][0], B[r], A[r][2], A[r][3]] for r in range(n)])
+    det3 = calc_det4([[A[r][0], A[r][1], B[r], A[r][3]] for r in range(n)])
+    det4 = calc_det4([[A[r][0], A[r][1], A[r][2], B[r]] for r in range(n)])
+    x1 = det1 / det
+    x2 = det2 / det
+    x3 = det3 / det
+    x4 = det4 / det
+    return x1, x2, x3, x4
+
+
+def solve_sle(A, B, n):
+    if n == 2:
+        return solve2(A, B)
+    if n == 3:
+        return solve3(A, B)
+    if n == 4:
+        return solve4(A, B)
+    print(f"! n should be 2/3/4, {n} got")
+    return None