Fortran 简明教程

-c Compile only, do not run the linker.
-o Specify the name of the output file, either an object file or the executable.

integer :: total
real :: average
complex :: cx
logical :: done
character(len = 80) :: message ! a string of 80 characters

total = 20000
average = 1666.67
done = .true.
message = “A big Hello from Tutorials Point”
cx = (3.0, 5.0) ! cx = 3.0 + 5.0i

cx = cmplx (1.0/2.0, -7.0) ! cx = 0.5 – 7.0i
cx = cmplx (x, y) ! cx = x + yi

program variableTesting
implicit none

   ! declaring variables
   integer :: total
   real :: average
   complex :: cx
   logical :: done
   character(len=80) :: message ! a string of 80 characters

   !assigning values
   total = 20000
   average = 1666.67
   done = .true.
   message = "A big Hello from Tutorials Point"
   cx = (3.0, 5.0) ! cx = 3.0 + 5.0i

   Print *, total
   Print *, average
   Print *, cx
   Print *, done
   Print *, message

end program variableTesting

20000
1666.67004
(3.00000000, 5.00000000 )
T
A big Hello from Tutorials Point

program gravitationalDisp

! this program calculates vertical motion under gravity
implicit none

   ! gravitational acceleration
   real, parameter :: g = 9.81

   ! variable declaration
   real :: s ! displacement
   real :: t ! time
   real :: u ! initial speed

   ! assigning values
   t = 5.0
   u = 50

   ! displacement
   s = u * t - g * (t**2) / 2

   ! output
   print *, "Time = ", t
   print *, 'Displacement = ',s

end program gravitationalDisp

Time = 5.00000000
Displacement = 127.374992

program testingChars
implicit none

   character (80) :: text
   integer :: i

   text = 'The intrinsic data type character stores characters and   strings.'
   i=index(text,'character')

   if (i /= 0) then
      print *, ' The word character found at position ',i
      print *, ' in text: ', text
   end if

end program testingChars

The word character found at position 25
in text : The intrinsic data type character stores characters and strings.

program hello
implicit none

   character(len = 15) :: surname, firstname
   character(len = 6) :: title
   character(len = 25)::greetings

   title = 'Mr.'
   firstname = 'Rowan'
   surname = 'Atkinson'

   print *, 'Here is', title, firstname, surname
   print *, 'Here is', trim(title),' ',trim(firstname),' ', trim(surname)

end program hello

 Here isMr.   Rowan          Atkinson
 Here isMr. Rowan Atkinson

program testingChars
implicit none

   character:: ch
   integer:: i

   do i = 65, 90
      ch = achar(i)
      print*, i, ' ', ch
   end do

end program testingChars

65  A
66  B
67  C
68  D
69  E
70  F
71  G
72  H
73  I
74  J
75  K
76  L
77  M
78  N
79  O
80  P
81  Q
82  R
83  S
84  T
85  U
86  V
87  W
88  X
89  Y
90  Z

program  datetime
implicit none

   character(len = 8) :: dateinfo ! ccyymmdd
   character(len = 4) :: year, month*2, day*2

   character(len = 10) :: timeinfo ! hhmmss.sss
   character(len = 2)  :: hour, minute, second*6

   call  date_and_time(dateinfo, timeinfo)

   !  let’s break dateinfo into year, month and day.
   !  dateinfo has a form of ccyymmdd, where cc = century, yy = year
   !  mm = month and dd = day

   year  = dateinfo(1:4)
   month = dateinfo(5:6)
   day   = dateinfo(7:8)

   print*, 'Date String:', dateinfo
   print*, 'Year:', year
   print *,'Month:', month
   print *,'Day:', day

   !  let’s break timeinfo into hour, minute and second.
   !  timeinfo has a form of hhmmss.sss, where h = hour, m = minute
   !  and s = second

   hour   = timeinfo(1:2)
   minute = timeinfo(3:4)
   second = timeinfo(5:10)

   print*, 'Time String:', timeinfo
   print*, 'Hour:', hour
   print*, 'Minute:', minute
   print*, 'Second:', second

end program  datetime

Date String: 20140803
Year: 2014
Month: 08
Day: 03
Time String: 075835.466
Hour: 07
Minute: 58
Second: 35.466

program trimString
implicit none

   character (len = *), parameter :: fname="Susanne", sname="Rizwan"
   character (len = 20) :: fullname

   fullname = fname//" "//sname !concatenating the strings

   print*,fullname,", the beautiful dancer from the east!"
   print*,trim(fullname),", the beautiful dancer from the east!"

end program trimString

Susanne Rizwan      , the beautiful dancer from the east!
 Susanne Rizwan, the beautiful dancer from the east!

program hello
implicit none

   character(len = 15) :: surname, firstname
   character(len = 6) :: title
   character(len = 40):: name
   character(len = 25):: greetings

   title = 'Mr. '
   firstname = 'Rowan'
   surname = 'Atkinson'
   greetings = 'A big hello from Mr. Beans'

   name = adjustl(title)//adjustl(firstname)//adjustl(surname)
   print *, 'Here is', name
   print *, greetings

   name = adjustr(title)//adjustr(firstname)//adjustr(surname)
   print *, 'Here is', name
   print *, greetings

   name = trim(title)//trim(firstname)//trim(surname)
   print *, 'Here is', name
   print *, greetings

end program hello

Here is Mr. Rowan  Atkinson
A big hello from Mr. Bean
Here is Mr. Rowan Atkinson
A big hello from Mr. Bean
Here is Mr.RowanAtkinson
A big hello from Mr. Bean

program hello
implicit none

   character(len=30) :: myString
   character(len=10) :: testString

   myString = 'This is a test'
   testString = 'test'

   if(index(myString, testString) == 0)then
      print *, 'test is not found'
   else
      print *, 'test is found at index: ', index(myString, testString)
   end if

end program hello

test is found at index: 11

program arrayProg

   real :: numbers(5) !one dimensional integer array
   integer :: matrix(3,3), i , j !two dimensional real array

   !assigning some values to the array numbers
   do i=1,5
      numbers(i) = i * 2.0
   end do

   !display the values
   do i = 1, 5
      Print *, numbers(i)
   end do

   !assigning some values to the array matrix
   do i=1,3
      do j = 1, 3
         matrix(i, j) = i+j
      end do
   end do

   !display the values
   do i=1,3
      do j = 1, 3
         Print *, matrix(i,j)
      end do
   end do

   !short hand assignment
   numbers = (/1.5, 3.2,4.5,0.9,7.2 /)

   !display the values
   do i = 1, 5
      Print *, numbers(i)
   end do

end program arrayProg

 2.00000000
 4.00000000
 6.00000000
 8.00000000
 10.0000000
         2
         3
         4
         3
         4
         5
         4
         5
         6
 1.50000000
 3.20000005
 4.50000000
0.899999976
 7.19999981

program dataStatement
implicit none

   integer :: a(5), b(3,3), c(10),i, j
   data a /7,8,9,10,11/

   data b(1,:) /1,1,1/
   data b(2,:)/2,2,2/
   data b(3,:)/3,3,3/
   data (c(i),i = 1,10,2) /4,5,6,7,8/
   data (c(i),i = 2,10,2)/5*2/

   Print *, 'The A array:'
   do j = 1, 5
      print*, a(j)
   end do

   Print *, 'The B array:'
   do i = lbound(b,1), ubound(b,1)
      write(*,*) (b(i,j), j = lbound(b,2), ubound(b,2))
   end do

   Print *, 'The C array:'
   do j = 1, 10
      print*, c(j)
   end do

end program dataStatement

 The A array:
           7
           8
           9
          10
          11
 The B array:
           1           1           1
           2           2           2
           3           3           3
 The C array:
           4
           2
           5
           2
           6
           2
           7
           2
           8
           2

program whereStatement
implicit none

   integer :: a(3,5), i , j

   do i = 1,3
      do j = 1, 5
         a(i,j) = j-i
      end do
   end do

   Print *, 'The A array:'

   do i = lbound(a,1), ubound(a,1)
      write(*,*) (a(i,j), j = lbound(a,2), ubound(a,2))
   end do

   where( a<0 )
      a = 1
   elsewhere
      a = 5
   end where

   Print *, 'The A array:'
   do i = lbound(a,1), ubound(a,1)
      write(*,*) (a(i,j), j = lbound(a,2), ubound(a,2))
   end do

end program whereStatement

 The A array:
           0           1           2           3           4
          -1           0           1           2           3
          -2          -1           0           1           2
 The A array:
           5           5           5           5           5
           1           5           5           5           5
           1           1           5           5           5

program deriveDataType

   !type declaration
   type Books
      character(len = 50) :: title
      character(len = 50) :: author
      character(len = 150) :: subject
      integer :: book_id
   end type Books

   !declaring type variables
   type(Books) :: book1
   type(Books) :: book2

   !accessing the components of the structure

   book1%title = "C Programming"
   book1%author = "Nuha Ali"
   book1%subject = "C Programming Tutorial"
   book1%book_id = 6495407

   book2%title = "Telecom Billing"
   book2%author = "Zara Ali"
   book2%subject = "Telecom Billing Tutorial"
   book2%book_id = 6495700

   !display book info

   Print *, book1%title
   Print *, book1%author
   Print *, book1%subject
   Print *, book1%book_id

   Print *, book2%title
   Print *, book2%author
   Print *, book2%subject
   Print *, book2%book_id

end program deriveDataType

 C Programming
 Nuha Ali
 C Programming Tutorial
   6495407
 Telecom Billing
 Zara Ali
 Telecom Billing Tutorial
   6495700

program pointerExample
implicit none

   integer, pointer :: p1
   integer, target :: t1
   integer, target :: t2

   p1=>t1
   p1 = 1

   Print *, p1
   Print *, t1

   p1 = p1 + 4
   Print *, p1
   Print *, t1

   t1 = 8
   Print *, p1
   Print *, t1

   nullify(p1)
   Print *, t1

   p1=>t2
   Print *, associated(p1)
   Print*, associated(p1, t1)
   Print*, associated(p1, t2)

   !what is the value of p1 at present
   Print *, p1
   Print *, t2

   p1 = 10
   Print *, p1
   Print *, t2

end program pointerExample

1
1
5
5
8
8
8
T
F
T
952754640
952754640
10
10

program pointerExample
implicit none

   integer, pointer :: a, b
   integer, target :: t
   integer :: n

   t = 1
   a => t
   t = 2
   b => t
   n = a + b

   Print *, a, b, t, n

end program pointerExample

2  2  2  4

Print "(f6.3)", pi

program printPi

   pi = 3.141592653589793238

   Print "(f6.3)", pi
   Print "(f10.7)", pi
   Print "(f20.15)", pi
   Print "(e16.4)", pi/100

end program printPi

3.142
3.1415927
3.141592741012573
0.3142E-01

program printName
implicit none

   character (len = 15) :: first_name
   print *,' Enter your first name.'
   print *,' Up to 20 characters, please'

   read *,first_name
   print "(1x,a)",first_name

end program printName

Enter your first name.
Up to 20 characters, please
Zara

program formattedPrint
implicit none

   real :: c = 1.2786456e-9, d = 0.1234567e3
   integer :: n = 300789, k = 45, i = 2
   character (len=15) :: str="Tutorials Point"

   print "(i6)", k
   print "(i6.3)", k
   print "(3i10)", n, k, i
   print "(i10,i3,i5)", n, k, i
   print "(a15)",str
   print "(f12.3)", d
   print "(e12.4)", c
   print '(/,3x,"n = ",i6, 3x, "d = ",f7.4)', n, d

end program formattedPrint

45
045
300789 45  2
300789 45  2
Tutorials Point
123.457
0.1279E-08

n = 300789 d = *******

read ([UNIT = ]u, [FMT = ]fmt, IOSTAT = ios, ERR = err, END = s)
write([UNIT = ]u, [FMT = ]fmt, IOSTAT = ios, ERR = err, END = s)

program outputdata
implicit none

   real, dimension(100) :: x, y
   real, dimension(100) :: p, q
   integer :: i

   ! data
   do i = 1,100
      x(i) = i * 0.1
      y(i) = sin(x(i)) * (1-cos(x(i)/3.0))
   end do

   ! output data into a file
   open(1, file = 'data1.dat', status='new')
   do i = 1,100
      write(1,*) x(i), y(i)
   end do
   close(1)

   ! opening the file for reading
   open (2, file = 'data1.dat', status = 'old')

   do i = 1,100
      read(2,*) p(i), q(i)
   end do

   close(2)

   do i = 1,100
      write(*,*) p(i), q(i)
   end do

end program outputdata

0.100000001  5.54589933E-05
0.200000003  4.41325130E-04
0.300000012  1.47636665E-03
0.400000006  3.45637114E-03
0.500000000  6.64328877E-03
0.600000024  1.12552457E-02
0.699999988  1.74576249E-02
0.800000012  2.53552198E-02
0.900000036  3.49861123E-02
1.00000000   4.63171229E-02
1.10000002   5.92407547E-02
1.20000005   7.35742599E-02
1.30000007   8.90605897E-02
1.39999998   0.105371222
1.50000000   0.122110792
1.60000002   0.138823599
1.70000005   0.155002072
1.80000007   0.170096487
1.89999998   0.183526158
2.00000000   0.194692180
2.10000014   0.202990443
2.20000005   0.207826138
2.29999995   0.208628103
2.40000010   0.204863414
2.50000000   0.196052119
2.60000014   0.181780845
2.70000005   0.161716297
2.79999995   0.135617107
2.90000010   0.103344671
3.00000000   6.48725405E-02
3.10000014   2.02930309E-02
3.20000005  -3.01767997E-02
3.29999995  -8.61928314E-02
3.40000010  -0.147283033
3.50000000  -0.212848678
3.60000014  -0.282169819
3.70000005  -0.354410470
3.79999995  -0.428629100
3.90000010  -0.503789663
4.00000000  -0.578774154
4.09999990  -0.652400017
4.20000029  -0.723436713
4.30000019  -0.790623367
4.40000010  -0.852691114
4.50000000  -0.908382416
4.59999990  -0.956472993
4.70000029  -0.995793998
4.80000019  -1.02525222
4.90000010  -1.04385209
5.00000000  -1.05071592
5.09999990  -1.04510069
5.20000029  -1.02641726
5.30000019  -0.994243503
5.40000010  -0.948338211
5.50000000  -0.888650239
5.59999990  -0.815326691
5.70000029  -0.728716135
5.80000019  -0.629372001
5.90000010  -0.518047631
6.00000000  -0.395693362
6.09999990  -0.263447165
6.20000029  -0.122622721
6.30000019   2.53026206E-02
6.40000010   0.178709000
6.50000000   0.335851669
6.59999990   0.494883657
6.70000029   0.653881252
6.80000019   0.810866773
6.90000010   0.963840425
7.00000000   1.11080539
7.09999990   1.24979746
7.20000029   1.37891412
7.30000019   1.49633956
7.40000010   1.60037732
7.50000000   1.68947268
7.59999990   1.76223695
7.70000029   1.81747139
7.80000019   1.85418403
7.90000010   1.87160957
8.00000000   1.86922085
8.10000038   1.84674001
8.19999981   1.80414569
8.30000019   1.74167395
8.40000057   1.65982044
8.50000000   1.55933595
8.60000038   1.44121361
8.69999981   1.30668485
8.80000019   1.15719533
8.90000057   0.994394958
9.00000000   0.820112705
9.10000038   0.636327863
9.19999981   0.445154816
9.30000019   0.248800844
9.40000057   4.95488606E-02
9.50000000  -0.150278628
9.60000038  -0.348357052
9.69999981  -0.542378068
9.80000019  -0.730095863
9.90000057  -0.909344316
10.0000000  -1.07807255

function name(arg1, arg2, ....) result (return_var_name)
   [declarations, including those for the arguments]
   [executable statements]
end function [name]

program calling_func
implicit none

   real :: a, b
   a = 2.0
   b = 3.0

   Print *, "Before calling swap"
   Print *, "a = ", a
   Print *, "b = ", b

   call swap(a, b)

   Print *, "After calling swap"
   Print *, "a = ", a
   Print *, "b = ", b

end program calling_func


subroutine swap(x, y)
implicit none

   real :: x, y, temp

   temp = x
   x = y
   y = temp

end subroutine swap

Before calling swap
a = 2.00000000
b = 3.00000000
After calling swap
a = 3.00000000
b = 2.00000000

module constants
implicit none

   real, parameter :: pi = 3.1415926536
   real, parameter :: e = 2.7182818285

contains
   subroutine show_consts()
      print*, "Pi = ", pi
      print*,  "e = ", e
   end subroutine show_consts

end module constants


program module_example
use constants
implicit none

   real :: x, ePowerx, area, radius
   x = 2.0
   radius = 7.0
   ePowerx = e ** x
   area = pi * radius**2

   call show_consts()

   print*, "e raised to the power of 2.0 = ", ePowerx
   print*, "Area of a circle with radius 7.0 = ", area

end program module_example

Pi = 3.14159274
e =  2.71828175
e raised to the power of 2.0 = 7.38905573
Area of a circle with radius 7.0 = 153.938049

module constants
implicit none

   real, parameter,private :: pi = 3.1415926536
   real, parameter, private :: e = 2.7182818285

contains
   subroutine show_consts()
      print*, "Pi = ", pi
      print*, "e = ", e
   end subroutine show_consts

end module constants


program module_example
use constants
implicit none

   real :: x, ePowerx, area, radius
   x = 2.0
   radius = 7.0
   ePowerx = e ** x
   area = pi * radius**2

   call show_consts()

   print*, "e raised to the power of 2.0 = ", ePowerx
   print*, "Area of a circle with radius 7.0 = ", area

end program module_example

   ePowerx = e ** x
   1
Error: Symbol 'e' at (1) has no IMPLICIT type
main.f95:19.13:

   area = pi * radius**2
   1
Error: Symbol 'pi' at (1) has no IMPLICIT type

module constants
implicit none

   real, parameter,private :: pi = 3.1415926536
   real, parameter, private :: e = 2.7182818285

contains
   subroutine show_consts()
      print*, "Pi = ", pi
      print*, "e = ", e
   end subroutine show_consts

   function ePowerx(x)result(ePx)
   implicit none
      real::x
      real::ePx
      ePx = e ** x
   end function ePowerx

   function areaCircle(r)result(a)
   implicit none
      real::r
      real::a
      a = pi * r**2
   end function areaCircle

end module constants


program module_example
use constants
implicit none

   call show_consts()

   Print*, "e raised to the power of 2.0 = ", ePowerx(2.0)
   print*, "Area of a circle with radius 7.0 = ", areaCircle(7.0)

end program module_example

Pi = 3.14159274
e = 2.71828175
e raised to the power of 2.0 = 7.38905573
Area of a circle with radius 7.0 = 153.938049

program numericFunctions
implicit none

   ! define constants
   ! define variables
   real :: a, b
   complex :: z

   ! values for a, b
   a = 15.2345
   b = -20.7689

   write(*,*) 'abs(a): ',abs(a),' abs(b): ',abs(b)
   write(*,*) 'aint(a): ',aint(a),' aint(b): ',aint(b)
   write(*,*) 'ceiling(a): ',ceiling(a),' ceiling(b): ',ceiling(b)
   write(*,*) 'floor(a): ',floor(a),' floor(b): ',floor(b)

   z = cmplx(a, b)
   write(*,*) 'z: ',z

end program numericFunctions

abs(a): 15.2344999   abs(b): 20.7688999
aint(a): 15.0000000  aint(b): -20.0000000
ceiling(a): 16  ceiling(b): -20
floor(a): 15  floor(b): -21
z: (15.2344999, -20.7688999)

program projectileMotion
implicit none

   ! define constants
   real, parameter :: g = 9.8
   real, parameter :: pi = 3.1415927

   !define variables
   real :: a, t, u, x, y

   !values for a, t, and u
   a = 45.0
   t = 20.0
   u = 10.0

   ! convert angle to radians
   a = a * pi / 180.0
   x = u * cos(a) * t
   y = u * sin(a) * t - 0.5 * g * t * t

   write(*,*) 'x: ',x,'  y: ',y

end program projectileMotion

x: 141.421356  y: -1818.57861

program kindSpecifier
implicit none

   real(kind = 4) :: a, b, c
   real(kind = 8) :: e, f, g
   integer(kind = 2) :: i, j, k
   integer(kind = 4) :: l, m, n
   integer :: kind_a, kind_i, kind_e, kind_l

   kind_a = kind(a)
   kind_i = kind(i)
   kind_e = kind(e)
   kind_l = kind(l)

   print *,'default kind for real is', kind_a
   print *,'default kind for int is', kind_i
   print *,'extended kind for real is', kind_e
   print *,'default kind for int is', kind_l

end program kindSpecifier

default kind for real is 4
default kind for int is 2
extended kind for real is 8
default kind for int is 4

program getSize
implicit none

   real (kind = 4) :: a
   real (kind = 8) :: b
   integer (kind = 2) :: i
   integer (kind = 4) :: j

   print *,'precision of real(4) =', precision(a)
   print *,'precision of real(8) =', precision(b)

   print *,'range of real(4) =', range(a)
   print *,'range of real(8) =', range(b)


   print *,'maximum exponent of real(4) =' , maxexponent(a)
   print *,'maximum exponent of real(8) =' , maxexponent(b)

   print *,'minimum exponent of real(4) =' , minexponent(a)
   print *,'minimum exponent of real(8) =' , minexponent(b)

   print *,'bits in integer(2) =' , bit_size(i)
   print *,'bits in integer(4) =' , bit_size(j)

end program getSize

precision of real(4) = 6
precision of real(8) = 15
range of real(4) = 37
range of real(8) = 307
maximum exponent of real(4) = 128
maximum exponent of real(8) = 1024
minimum exponent of real(4) = -125
minimum exponent of real(8) = -1021
bits in integer(2) = 16
bits in integer(4) = 32

program getKind
implicit none

   integer:: i
   i = selected_real_kind (p = 10, r = 99)
   print *,'selected_real_kind (p = 10, r = 99)', i

end program getKind

selected_real_kind (p = 10, r = 99) 8