I have an input file that looks like:
text
6
1w 1 3.450 1.324 2.915
1w 2 3.450 1.324 2.915
4w 2 3.458 1.379 2.837
4w 1 3.458 1.379 2.837
7w 2 3.364 1.345 2.951
7w 2 3.364 1.345 2.951
and I want the output file to look like:
text
6
1w N 3.450 1.324 2.915
1w H1 3.450 1.324 2.915
4w H2 3.458 1.379 2.837
4w N 3.458 1.379 2.837
7w H1 3.364 1.345 2.951
7w HW2 3.364 1.345 2.951
For the second column, the numbers 1 2 2 1 2 2, I need to print "N" for 1 and "H1" and "H2" for 2 and than again NH1H2, so I mean to tell the program to change once 2 for H1 and then H2. I used
if(p==1)p="N"
if(p==2)p="H1"
but I have no idea how to put do cycle to tell the second 2 is H2 not H1. Can you suggest what to do?
You probably want to keep a running count of the H elements, something like
program p
implicit none
character(2), allocatable :: element_symbols(:)
character(100) :: text
integer :: no_elements
character(2) :: name
integer :: element_id
character(2) :: element_symbol
real :: x,y,z
integer :: h_count
integer :: i,input
! The elemental symbols, so 1->"N", 2->"H" etc.
element_symbols = ['N', 'H']
h_count = 0
open(10, file='input.dat')
open(11, file='output.dat')
read(10,*) text
write(11,*) text
read(10,*) no_elements
write(11,*) no_elements
do i=1,no_elements
read(10,*) name, element_id, x, y, z
element_symbol = element_symbols(element_id)
if (element_symbol=="N") then
! If the element is `N`, reset h_count.
h_count = 0
elseif (element_symbol=="H") then
! If the element is `H`, update h_count.
h_count = h_count + 1
write(element_symbol,'(A,I0)') trim(element_symbol), h_count
endif
write(11,*) name, element_symbol, x, y, z
enddo
end program
Related
I want to write to file elements of the three arrays: k= (/1, 2 /), kp = (/1, 2 /), w(k,kp) = (/1,2 ,3,4/)
in the following pattern, using Fortran:
k kp w(k,kp)
1 1 1
1 2 2
2 1 3
2 2 4
I know how to write for column "kp" and "w", but how can I write column "k" ?
I have my code as:
write(20,*) "k" , "kp", "W"
do i = 1,2
do j = 1, 2
write (20,*) k( ) kp(j) , W(i,j)
end do
end do
Is this homework problem?
program foo
implicit none
integer :: i, j, k(2) = [1,2], kp(2) = [1,2]
integer :: w(2,2) = reshape([1,3,2,4], [2,2])
do j = 1, 2
do i = 1, 2
write(*,'(*(1X,I0))') k(j), kp(i), w(k(j),kp(i))
end do
end do
end program foo
need to use SUM() and dim
the problem in the sum() algorithm does not calculate correctly, I can’t fix it, I need someone’s help
program main
use environment
implicit none
character(*), parameter :: input_file = "../data/input.txt", output_file = "output.txt"
integer :: In = 0, Out = 0, rows = 0, columns = 0!, i = 0
integer, allocatable :: A(:,:)
integer :: res_rows = 0, res_columns = 0
open (file=input_file, newunit=In)
read(In, *) rows, columns
allocate(A(rows, columns))
read (In, *) A
close (In)
res_rows = sum(A(1:columns+1,1), dim=1)
res_columns = sum(A(1:rows+1,1), dim=1)
!outout data
open (file=output_file, encoding=E_, newunit=Out, position='append')
write(*,*)"rows:",res_rows
write(*,*)"columns:",res_columns
close (Out)
end program main
input data from txt file
4 3
1 1 2
4 3 4
1 1 2
4 3 2
output data to txt file
rows: 4 11 4 9
columns: 10 8 10
Fortran is a column-major language. Your read(in,*) a is populating the matrix in the wrong order. Try writing out the first row of your matrix a. Your use of the sum intrinsic is also wrong. See below.
program main
implicit none
character(*), parameter :: input_file = "a.dat"
integer i, in, out, rows, columns
integer, allocatable :: a(:,:)
integer :: res_rows = 0, res_columns = 0
open(file=input_file, newunit=in, status='old')
read(in, *) rows, columns
allocate(a(rows, columns))
do i = 1, rows
read(in,*) a(i,:)
end do
close(in)
print '(A,4(1X,I0))', 'Sum of each row:', sum(a,dim=2)
do i = 1, rows
print '(3I3,A,I0)', a(i,:),' = ', sum(a(i,:))
end do
print *
print '(A,4(1X,I0))', 'Sum of each column:', sum(a,dim=1)
do i = 1, columns
print '(4I3,A,I0)', a(:,i),' = ',sum(a(:,i))
end do
end program main
I have a problem how to print only specific three numbers, which are in a file with no format. I have no idea how to read it and print because if I use read from higher i, it does not start reading e.g. for i = 4, the line 4. I need only numbers 88.98, 65.50, and 30.
text
678 people
450 girls
22 old people
0 cats
0 dogs
4 girls blond
1 boy blond
1 old man
0 88.9814 xo xi
0 65.508 yo yi
0 30 zo zi
I tried this, but this is not working at all.
program souradnice
implicit none
integer :: i, k
character*100 :: yo, zo, line, name, text
real :: xo
open(10,file="text.dat", status='old')
do i=20,20
read(10,fmt='(a)') line
read(unit=line, fmt='(a100)') text
if(name=="xo") then
print *, trim(text)
endif
enddo
close(10)
end program souradnice
You need to read the whole file line by line, and check each line to see if it's the one you want, e.g. by using the index intrinsic. For example,
program souradnice
implicit none
character(100) :: line
character(5) :: matches(3)
real :: numbers(3)
character(10) :: dummy
integer :: i, ierr
! Substrings to match to find the relevant lines
matches = ["xo xi", "yo yi", "zo zi"]
open(10,file="text.dat", status='old')
do
! Read a line from the file, and exit the loop if the file end is reached.
read(10,fmt='(a)',iostat=ierr) line
if (ierr<0) then
exit
endif
do i=1,3
! Check if `line` matches any of the i'th line we want.
if (index(line, matches(i))>0) then
! If it matches, read the relevant number into `numbers`.
read(line,*) dummy, numbers(i)
endif
enddo
enddo
write(*,*) numbers
end program
I have a data file with 2 columns. Let's say:
column 1 (8,8,8,6,9), reading it as a.
column 2 (3,4,5,6,7), reading it as b.
I want to write a code checking if a(i)=a(i+1) then b=0.
So result should be column 1 as a: (8,8,8,6,7), column 2 as b should be (0,0,0,6,7).
I tried this but failed:
program read2cols
implicit none
integer ::ios,i,j
real a,b
open(file='8081.txt', unit=22, status='old', action='read')
do
read(22,*,iostat=ios) a(i),b(j)
if(a(i)<a(i))b=0
if(ios/=0) exit
print*,a,b
enddo
close(22)
end program read2cols
Your program can be something like this:
program read2cols
implicit none
integer :: ios, i, j
real :: a(5), b(5)
open(file='8081.txt', unit=22, status='old', action='read')
read(22, *, iostat = ios) a(1), b(1)
do i = 2,5
read(22, *, iostat = ios) a(i), b(i)
if (ios /= 0) exit
if (a(i-1) == a(i)) b(i-1) = 0
end do
print *, a, b
close(22)
end program read2cols
Output:
8.00000000 8.00000000 8.00000000 6.00000000 9.00000000
0.00000000 0.00000000 5.00000000 6.00000000 7.00000000
Notes:
You declare a and b as scalars, then index through them using i, fix this by declaring a(5), b(5) as arrays. The loop index is missing in do .., it should read do i = ... Finally, the condition should be if (a(i-1) == a(i)) b(i-1) = 0 because you can compare a value only after it is read.
I have to compute few complex integrals and for this purpose I got from my supervisor old program written in Fortran 77. However I have few problems with it. Mostly associated with syntax errors of DATA Statement. This is a part of code with a function calculating real integrals:
FUNCTION CAUSSA(F,A,B,EPS)
IMPLICIT DOUBLE PRECISION (A-H,O-Z)
external f
REAL :: W(12),X(12)
DATA CONST /1.0D-12/
DATA W &
1 /0.10122 85362 9037 , 0.22238 10344 5337 , 0.31370 66458 7788 ,&
2 0.36268 37833 7836 , 0.02715 24594 1175 , 0.06225 35239 3864 ,&
3 0.09515 85116 8249 , 0.12462 89712 5553 , 0.14959 59888 1657 ,&
4 0.16915 65193 9500 , 0.18260 34150 4492 , 0.18945 06104 5506 /
DATA X &
1 /0.96028 98564 9753 , 0.79666 64774 1362 , 0.52553 24099 1632 ,&
2 0.18343 46424 9565 , 0.98940 09349 9165 , 0.94457 50230 7323 ,&
3 0.86563 12023 8783 , 0.75540 44083 5500 , 0.61787 62444 0264 ,&
4 0.45801 67776 5722 , 0.28160 35507 7925 , 0.09501 25098 3763 /
DELTA=CONST*DABS(A-B)
CAUSSA=0.d0
AA=A
5 Y=B-AA
IF(DABS(Y) .LE. DELTA) RETURN
2 BB=AA+Y
C1=0.5*(AA+BB)
C2=C1-AA
S8=0.d0
S16=0.d0
DO 1 I=1,4
U=X(I)*C2
1 S8=S8+W(I)*(F(C1+U)+F(C1-U))
DO 3 I = 5,12
U=X(I)*C2
3 S16=S16+W(I)*(F(C1+U)+F(C1-U))
S8=S8*C2
S16=S16*C2
IF(DABS(S16-S8).GT.EPS*DABS(S16)) GO TO 4
CAUSSA= CAUSSA+S16
A=BB
GO TO 5
4 Y=0.5*Y
IF(DABS(Y) .GT. DELTA) GO TO 2
write(2,7)
write(5,7)
7 FORMAT(1X,35HCAUSSA...TOO HIGH ACCURACY REQUIRED)
CAUSSA=0.d0
RETURN
END
The result of compilation is following:
sample.f90:11:
1 /0.10122 85362 9037 , 0.22238 10344 5337 , 0.31370 66458 7788 ,&
1
Error: Syntax error in DATA statement at (1)
sample.f90:17:
1 /0.96028 98564 9753 , 0.79666 64774 1362 , 0.52553 24099 1632 ,&
1
Error: Syntax error in DATA statement at (1)
I use gfortran version 4.4.7. I tried to rewrite those arrays but the result is always the same. Although this function is not the best for integrating, I still need it. Without it, that old program is collapsing.
I would appreciate any advice.
If you want to compile this as free form source, there are two things you will probably need to change
I am pretty sure that labels are illegal in continuation lines, so they should be removed
gfortran will misinterpreted the spaces between sections of the floating point numbers, so those also should be removed.
Something like this:
DATA W &
/0.10122853629037 , 0.22238103445337 , 0.31370664587788 ,&
0.36268378337836 , 0.02715245941175 , 0.06225352393864 ,&
0.09515851168249 , 0.12462897125553 , 0.14959598881657 ,&
0.16915651939500 , 0.18260341504492 , 0.18945061045506 /
should probably compile correctly [note written in browser and not tested].
Your original code was erroneously mixing both free-form and fixed-source format. Line continuations in free-form are performed by using a trailing ampersand character, &, rather than entering a character in column 6 of the following line. In fixed-source form, the first six columns are reserved for statement labels, with column 1 also used to indicate comment lines. In modern code, using structured control statements (such as select case or if-then-else) statement labels are uncommon. The first five columns are therefore wasted because they are rarely used.
Here is the same code in free-form and fixed-source format:
program main
use ISO_Fortran_env, only: &
compiler_version, &
compiler_options
! Explicit typing only
implicit none
! Variable declarations
double precision :: a, b, eps, x
a = 1.0d0
b = 2.0d0
eps = epsilon(a)
x = caussa(my_func, a, b, eps)
print '(/4a/)', &
' This file was compiled using ', compiler_version(), &
' using the options ', compiler_options()
contains
function my_func(arg) result (return_value)
! Dummy arguments
double precision, intent (in) :: arg
double precision :: return_value
return_value = arg * 42.0d0
end function my_func
function caussa(f,a,b,eps)
use ISO_Fortran_env, only: &
stderr => ERROR_UNIT
implicit double precision (a-h,o-z)
external f
integer :: i
real :: w(12),x(12)
data const /1.0d-12/
data w &
/0.10122853629037, 0.22238103445337, 0.31370664587788 ,&
0.36268378337836, 0.02715245941175, 0.06225352393864 , &
0.09515851168249, 0.12462897125553, 0.14959598881657 , &
0.16915651939500, 0.18260341504492, 0.18945061045506 /
data x &
/0.96028985649753, 0.79666647741362, 0.52553240991632, &
0.18343464249565, 0.98940093499165, 0.94457502307323, &
0.86563120238783, 0.75540440835500, 0.61787624440264, &
0.45801677765722, 0.28160355077925, 0.09501250983763 /
delta=const*dabs(a-b)
caussa=0.d0
aa=a
5 y=b-aa
if (dabs(y) <= delta) return
2 bb=aa+y
c1=0.5*(aa+bb)
c2=c1-aa
s8=0.d0
s16=0.d0
do 1 i=1,4
u=x(i)*c2
1 s8=s8+w(i)*(f(c1+u)+f(c1-u))
do 3 i = 5,12
u=x(i)*c2
3 s16=s16+w(i)*(f(c1+u)+f(c1-u))
s8=s8*c2
s16=s16*c2
if (dabs(s16-s8)>eps*dabs(s16)) go to 4
caussa = caussa+s16
a = bb
go to 5
4 y = 0.5*y
if (dabs(y) > delta) go to 2
write(2,7)
write(stderr,7)
!
! 7 format(1x,35hcaussa...too high accuracy required)
! Hollerith format specifier is a Fortran 95 deleted feature
!
7 format(1x, 'caussa...too high accuracy required')
caussa=0.d0
end function caussa
end program main
Here's the fixed-form version
PROGRAM MAIN
USE ISO_FORTRAN_ENV, ONLY:
1 COMPILER_VERSION,
2 COMPILER_OPTIONS
C EXPLICIT TYPING ONLY
IMPLICIT NONE
C VARIABLE DECLARATIONS
DOUBLE PRECISION :: A, B, EPS, X
A = 1.0D0
B = 2.0D0
EPS = EPSILON(A)
X = CAUSSA(MY_FUNC, A, B, EPS)
PRINT '(/4A/)',
1 ' THIS FILE WAS COMPILED USING ', COMPILER_VERSION(),
2 ' USING THE OPTIONS ', COMPILER_OPTIONS()
CONTAINS
FUNCTION MY_FUNC(ARG) RESULT (RETURN_VALUE)
C DUMMY ARGUMENTS
DOUBLE PRECISION, INTENT (IN) :: ARG
DOUBLE PRECISION :: RETURN_VALUE
RETURN_VALUE = ARG * 42.0D0
END FUNCTION MY_FUNC
FUNCTION CAUSSA(F,A,B,EPS)
USE ISO_FORTRAN_ENV, ONLY:
1 STDERR => ERROR_UNIT
IMPLICIT DOUBLE PRECISION (A-H,O-Z)
EXTERNAL F
INTEGER I
REAL :: W(12), X(12)
DATA CONST /1.0D-12/
DATA W
1 /0.10122 85362 9037, 0.22238 10344 5337, 0.31370 66458 7788,
2 0.36268 37833 7836, 0.02715 24594 1175, 0.06225 35239 3864,
3 0.09515 85116 8249, 0.12462 89712 5553, 0.14959 59888 1657,
4 0.16915 65193 9500, 0.18260 34150 4492, 0.18945 06104 5506 /
DATA X
1 /0.96028 98564 9753, 0.79666 64774 1362, 0.52553 24099 1632,
2 0.18343 46424 9565, 0.98940 09349 9165, 0.94457 50230 7323,
3 0.86563 12023 8783, 0.75540 44083 5500, 0.61787 62444 0264,
4 0.45801 67776 5722, 0.28160 35507 7925, 0.09501 25098 3763 /
DELTA=CONST*DABS(A-B)
CAUSSA=0.D0
AA=A
5 Y=B-AA
IF(DABS(Y) .LE. DELTA) RETURN
2 BB=AA+Y
C1=0.5*(AA+BB)
C2=C1-AA
S8=0.D0
S16=0.D0
DO 1 I=1,4
U=X(I)*C2
1 S8=S8+W(I)*(F(C1+U)+F(C1-U))
DO 3 I = 5,12
U=X(I)*C2
3 S16=S16+W(I)*(F(C1+U)+F(C1-U))
S8=S8*C2
S16=S16*C2
IF(DABS(S16-S8).GT.EPS*DABS(S16)) GO TO 4
CAUSSA= CAUSSA+S16
A=BB
GO TO 5
4 Y=0.5*Y
IF(DABS(Y) .GT. DELTA) GO TO 2
WRITE(2,7)
WRITE(STDERR,7)
C
C 7 FORMAT(1X,35HCAUSSA...TOO HIGH ACCURACY REQUIRED)
C HOLLERITH FORMAT SPECIFIER IS A FORTRAN 95 DELETED FEATURE
C
7 FORMAT(1X, 'CAUSSA...TOO HIGH ACCURACY REQUIRED')
CAUSSA=0.D0
RETURN
END FUNCTION CAUSSA
END PROGRAM MAIN
With free-form, the concept of “significant blanks” was introduced.
In fixed-source, blanks were insignificant in most contexts. Here is a sample of a fixed-source statement showing what are now considered significant blanks followed by an equivalent statement without the blanks:
DO N = 1, MAX ITER S
DO N = 1, MAXITERS
Notice how we rewrote
DATA W
1 /0.10122 85362 9037, blah blah
as
data w &
/0.10122853629037, blah blah