update

2025.07.24_programming_with_python_and_fortran/example_1/a.py

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+import example
+example.hello()

2025.07.24_programming_with_python_and_fortran/example_1/example.f90

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+subroutine hello()
+    print *, "Hello from Fortran!"
+end subroutine hello

2025.07.24_programming_with_python_and_fortran/example_2/a.py

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+import example
+
+matrix = [[1, 2], [3, 4]]
+print(example.sum_matrix(matrix))
+
+print('---')
+
+# 时间对比
+
+import numpy as np
+import time
+
+matrix = np.random.rand(5000, 5000)
+
+start = time.time()
+print(example.sum_matrix(matrix))
+end = time.time()
+print('Python + Fortran 循环求和时间：', end - start)
+
+start = time.time()
+sum_result = 0
+for i0 in range(matrix.shape[0]):
+    for j0 in range(matrix.shape[1]):
+        sum_result += matrix[i0, j0]
+print(sum_result)
+end = time.time()
+print('Python 循环求和时间：', end - start)
+
+from numba import jit
+@jit
+def numba_for_sum_matrix(matrix):
+    sum_result = 0
+    for i0 in range(matrix.shape[0]):
+        for j0 in range(matrix.shape[1]):
+            sum_result += matrix[i0, j0]
+    return sum_result
+
+start = time.time()
+print(numba_for_sum_matrix(matrix))
+end = time.time()
+print('Python numba 循环求和时间：', end - start)
+
+start = time.time()
+print(np.sum(matrix))
+end = time.time()
+print('Python numpy.sum() 求和时间：', end - start)

2025.07.24_programming_with_python_and_fortran/example_2/example.f90

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+subroutine sum_matrix(matrix, total)
+    implicit none
+    ! 输入参数
+    real, intent(in)  :: matrix(:,:)  ! 假定形状数组
+    real, intent(out) :: total  ! 输出总和
+    
+    ! 局部变量
+    integer :: i, j
+    
+    ! 双重循环计算总和
+    total = 0.0
+    do j = 1, size(matrix, 2)  ! 获取列数
+        do i = 1, size(matrix, 1)  ! 获取行数
+            total = total + matrix(i, j)
+        end do
+    end do
+end subroutine sum_matrix

2025.07.24_programming_with_python_and_fortran/example_3/a.py

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+import numpy as np
+import example
+
+A = [[1.0, 2.0, 3.0],
+    [0.0, 1.0, 4.0],
+    [5.0, 6.0, 0.0]]
+
+Ainv_1 = np.asfortranarray(np.empty_like(A))
+example.inverse_matrix(A, Ainv_1) # 调用 Fortran 子程序
+print(Ainv_1)
+
+Ainv_2 = np.linalg.inv(A)
+print(Ainv_2)
+
+print('---')
+
+# 时间对比
+
+A = np.random.rand(3000, 3000)
+
+import time
+start = time.time()
+Ainv_1 = np.asfortranarray(np.empty_like(A))
+example.inverse_matrix(A, Ainv_1) # 调用 Fortran 子程序
+end = time.time()
+print('Python + Fortran 求逆时间：', end - start)
+
+start = time.time()
+Ainv_2 = np.linalg.inv(A)
+end = time.time()
+print('Python np.linalg.inv() 求逆时间：', end - start)

2025.07.24_programming_with_python_and_fortran/example_3/example.f90

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+! 矩阵求逆子程序
+subroutine inverse_matrix(A, Ainv)
+    implicit none
+    real(8), intent(in) :: A(:,:)       ! 输入矩阵
+    real(8), intent(inout) :: Ainv(:,:)    ! 输出逆矩阵
+    real(8), allocatable :: work(:)
+    integer, allocatable :: ipiv(:)
+    integer :: n, info
+
+    n = size(A,1)
+    allocate(ipiv(n), work(n))
+    
+    Ainv = A  ! 复制输入矩阵
+    
+    call dgetrf(n, n, Ainv, n, ipiv, info)  ! LU 分解
+    call dgetri(n, Ainv, n, ipiv, work, n, info) ! 计算逆矩阵
+        
+    deallocate(ipiv, work)
+end subroutine inverse_matrix