Fortran چیست؟ آموزش کامل و جامع Fortran

program hello
    implicit none
    print *, "سلام دنیا!"
end program hello

program example
    implicit none
    ! تعریف متغیرها
    integer :: x, y
    real :: result

    ! دستورات اجرایی
    x = 5
    y = 3
    result = x + y
    print *, "Result:", result

end program example

program data_types
    implicit none
    
    ! انواع داده عددی
    integer :: i = 42
    real :: x = 3.14
    double precision :: d = 3.14159265359
    complex :: c = (1.0, 2.0)
    
    ! نوع منطقی
    logical :: flag = .true.
    
    ! رشته‌ها
    character(len=10) :: str = "Fortran"
    
    print *, "Integer:", i
    print *, "Real:", x
    print *, "Double:", d
    print *, "Complex:", c
    print *, "Logical:", flag
    print *, "String:", str
    
end program data_types

program arrays
    implicit none
    
    ! تعریف آرایه‌ها
    integer, dimension(5) :: vector = [1, 2, 3, 4, 5]
    real, dimension(3,3) :: matrix
    integer :: i, j
    
    ! مقداردهی ماتریس
    do i = 1, 3
        do j = 1, 3
            matrix(i,j) = i + j
        end do
    end do
    
    ! عملیات برداری
    print *, "Vector sum:", sum(vector)
    print *, "Matrix trace:", sum([(matrix(i,i), i=1,3)])
    
end program arrays

program control_structures
    implicit none
    integer :: i, sum
    
    ! حلقه DO
    sum = 0
    do i = 1, 10
        sum = sum + i
    end do
    
    ! شرط IF
    if (sum > 50) then
        print *, "مجموع بزرگتر از 50 است"
    else if (sum == 50) then
        print *, "مجموع برابر 50 است"
    else
        print *, "مجموع کوچکتر از 50 است"
    end if
    
    ! CASE ساختار
    select case (sum)
        case (1:10)
            print *, "مجموع بین 1 تا 10 است"
        case (11:20)
            print *, "مجموع بین 11 تا 20 است"
        case default
            print *, "مجموع بزرگتر از 20 است"
    end select
    
end program control_structures

module math_operations
    implicit none
contains
    ! تعریف تابع
    function factorial(n) result(fact)
        integer, intent(in) :: n
        integer :: fact, i
        
        fact = 1
        do i = 1, n
            fact = fact * i
        end do
    end function factorial
    
    ! تعریف زیربرنامه
    subroutine swap(a, b)
        integer, intent(inout) :: a, b
        integer :: temp
        
        temp = a
        a = b
        b = temp
    end subroutine swap
end module math_operations

program main
    use math_operations
    implicit none
    integer :: x = 5, y = 10
    
    print *, "Factorial of 5:", factorial(5)
    
    print *, "Before swap:", x, y
    call swap(x, y)
    print *, "After swap:", x, y
end program main

program io_examples
    implicit none
    integer :: age
    real :: height
    character(len=20) :: name
    
    ! خواندن از ورودی
    print *, "Enter your name:"
    read *, name
    
    print *, "Enter your age and height:"
    read *, age, height
    
    ! نوشتن در فایل
    open(unit=10, file="data.txt", status="replace")
    write(10,*) "Name:", trim(name)
    write(10,*) "Age:", age
    write(10,*) "Height:", height
    close(10)
    
    print *, "Data has been written to data.txt"
end program io_examples

! برنامه‌نویسی شیءگرا
module shape_module
    implicit none
    
    type :: Shape
        real :: area
    contains
        procedure :: calculate_area
    end type Shape
    
    type, extends(Shape) :: Rectangle
        real :: width
        real :: height
    contains
        procedure :: calculate_area => rectangle_area
    end type Rectangle
contains
    function rectangle_area(this) result(area)
        class(Rectangle), intent(in) :: this
        real :: area
        area = this%width * this%height
    end function rectangle_area
end module shape_module

! برنامه‌نویسی موازی
program parallel_example
    use omp_lib
    implicit none
    integer :: i
    
    !$omp parallel do
    do i = 1, 1000
        call heavy_computation(i)
    end do
    !$omp end parallel do
    
contains
    subroutine heavy_computation(n)
        integer, intent(in) :: n
        ! محاسبات سنگین
    end subroutine heavy_computation
end program parallel_example

! استفاده از ماژول‌ها
module utilities
    implicit none
    private  ! همه چیز خصوصی است مگر موارد مشخص شده
    public :: helper_function  ! فقط این تابع عمومی است

contains
    function helper_function(x) result(y)
        real, intent(in) :: x
        real :: y
        y = x * 2
    end function helper_function
end module utilities

! برنامه اصلی
program main
    use utilities
    implicit none
    
    ! متغیرها در ابتدا
    integer :: i
    real :: result
    
    ! کد اصلی
    result = helper_function(3.14)
end program main

program optimization
    implicit none
    real, dimension(1000,1000) :: matrix
    integer :: i, j
    
    ! روش کارآمد - دسترسی ستونی در Fortran
    do j = 1, 1000
        do i = 1, 1000
            matrix(i,j) = i + j
        end do
    end do
end program optimization

program numerical_integration
    implicit none
    real :: a = 0.0, b = 1.0  ! بازه انتگرال‌گیری
    integer :: n = 1000       ! تعداد نقاط
    real :: result
    
    result = trapezoidal_integration(a, b, n)
    print *, "Integral result:", result

contains
    function trapezoidal_integration(a, b, n) result(integral)
        real, intent(in) :: a, b
        integer, intent(in) :: n
        real :: integral, h, x
        integer :: i
        
        h = (b - a) / n
        integral = 0.5 * (func(a) + func(b))
        
        do i = 1, n-1
            x = a + i * h
            integral = integral + func(x)
        end do
        
        integral = integral * h
    end function
    
    function func(x) result(y)
        real, intent(in) :: x
        real :: y
        y = x**2  ! تابع مورد نظر برای انتگرال‌گیری
    end function
end program numerical_integration

program particle_motion
    implicit none
    real :: position(3) = [0.0, 0.0, 0.0]
    real :: velocity(3) = [1.0, 2.0, -0.5]
    real :: dt = 0.01
    integer :: i
    
    do i = 1, 100
        call update_position(position, velocity, dt)
        print *, "Time:", i*dt, "Position:", position
    end do

contains
    subroutine update_position(pos, vel, dt)
        real, intent(inout) :: pos(3)
        real, intent(in) :: vel(3), dt
        
        pos = pos + vel * dt
    end subroutine
end program particle_motion