fortran实现加法
时间: 2023-10-11 17:06:46 浏览: 59
Fortran实现加法很简单,可以使用"+"操作符直接进行加法运算。下面是一个简单的Fortran程序示例,实现两个数的加法:
```fortran
program add_numbers
implicit none
integer :: num1, num2, sum
! 读取用户输入的两个数
write(*,*) '请输入两个整数:'
read(*,*) num1, num2
! 计算两个数的和
sum = num1 + num2
! 输出结果
write(*,*) '两个数的和为:', sum
end program add_numbers
```
在这个程序中,我们先定义了三个整型变量`num1`、`num2`和`sum`,分别表示用户输入的第一个数、第二个数和它们的和。然后通过`read`语句读取用户输入的两个数,使用"+"操作符计算它们的和,并通过`write`语句输出结果。
当你运行这个程序时,它会提示你输入两个整数,然后输出它们的和。
相关问题
fortran实现jacobi
下面是Fortran实现Jacobi方法的代码:
```
program jacobi
implicit none
integer :: n, i, j, k, itermax, iter
real :: tol, diff, sum
real, dimension(100,100) :: a, b, x, xnew
! 读入矩阵维数和迭代次数
print *, "Enter the matrix size:"
read *, n
print *, "Enter the maximum number of iterations:"
read *, itermax
! 读入矩阵元素和右端向量
print *, "Enter the matrix elements:"
do i = 1, n
do j = 1, n
read *, a(i,j)
end do
end do
print *, "Enter the right-hand side vector:"
do i = 1, n
read *, b(i)
end do
! 初始化解向量
x = 0.0
xnew = 0.0
! 设置迭代停止条件
tol = 1.0e-6
! 开始迭代
do iter = 1, itermax
! 计算新的解向量
do i = 1, n
sum = b(i)
do j = 1, n
if (i /= j) then
sum = sum - a(i,j)*x(j)
end if
end do
xnew(i) = sum/a(i,i)
end do
! 计算当前解向量和新的解向量之间的差异
diff = 0.0
do i = 1, n
diff = diff + abs(xnew(i) - x(i))
end do
! 更新解向量
x = xnew
! 判断是否满足停止条件
if (diff < tol) then
print *, "Convergence achieved after ", iter, " iterations."
exit
end if
end do
! 如果迭代次数达到了最大值,仍然没有满足停止条件,则认为算法失败
print *, "Iteration failed to converge within ", itermax, " iterations."
end program jacobi
```
fortran 实现汉克尔变换
汉克尔变换是一种数学变换,用于将时域信号转换为频域信号。Fortran可以使用快速傅里叶变换(FFT)算法来实现汉克尔变换。
以下是Fortran代码示例:
```fortran
program hankel_transform
implicit none
integer :: i, j, n
real :: pi, dx, x_min, x_max
real, dimension(:), allocatable :: x, h, f, g
! 初始化变量
n = 1000
pi = 3.14159265358979323846
x_min = 0.0
x_max = 10.0*pi
dx = (x_max-x_min)/real(n-1)
allocate(x(n))
allocate(h(n))
allocate(f(n))
allocate(g(n))
! 生成数据
do i = 1, n
x(i) = x_min + dx*real(i-1)
f(i) = sin(x(i))
end do
! 计算汉克尔变换
do i = 1, n
h(i) = 0.0
do j = 1, n
h(i) = h(i) + f(j)*besselj0(x(i)*x(j))/x(j)
end do
end do
! 输出结果
do i = 1, n
write(*,*) x(i), h(i)
end do
! 释放内存
deallocate(x)
deallocate(h)
deallocate(f)
deallocate(g)
contains
! Bessel函数
real function besselj0(x)
real :: x, sum, term
integer :: k, n
n = 100
sum = 0.0
do k = 0, n
term = (-1.0)**k/(factorial(k)*factorial(k))*x**(2*k)
sum = sum + term
end do
besselj0 = sum
end function besselj0
end program hankel_transform
```
该代码使用了Bessel函数来计算汉克尔变换。首先生成1000个sin函数值,然后通过循环计算每个汉克尔变换的值。最后输出结果。