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I have a .dat file , from which I am trying to read line by line and print it. Can anyone please help about how to do it in fortran?
Thanks in advance!
Data:
REMARK GENERATED BY TRJCONV
TITLE UNNAMED t= 0.00000
REMARK THIS IS A SIMULATION BOX
CRYST1 26.178 26.178 26.178 90.00 90.00 90.00 P 1 1
MODEL 1
ATOM 1 S2 LJ2 1 17.000 15.030 11.630 1.00 0.00
ATOM 2 S2 LJ2 2 13.290 11.340 15.900 1.00 0.00
ATOM 3 S2 LJ2 3 17.030 23.070 14.750 1.00 0.00
ATOM 4 S2 LJ2 4 15.360 14.840 9.480 1.00 0.00
ATOM 5 S2 LJ2 5 15.780 4.560 9.580 1.00 0.00
ATOM 6 S2 LJ2 6 5.350 22.490 11.110 1.00 0.00
ATOM 7 S2 LJ2 7 19.940 3.910 10.840 1.00 0.00
ATOM 8 S2 LJ2 8 20.380 13.360 15.680 1.00 0.00
ATOM 9 S2 LJ2 9 18.340 4.200 7.720 1.00 0.00
ATOM 10 S2 LJ2 10 18.610 16.530 9.910 1.00 0.00
TER
ENDMDL
Code:
program atom_test
implicit none
character (LEN=75) ::inputdatafile,outputfile
real,dimension(100) :: x, y
integer :: i,n,nframes
character (len=200),dimension(3000):: command
print *,"Give the datafile name:"
read *,inputdatafile
outputfile=inputdatafile(1:len(trim(inputdatafile))-4)//"_output.dat"
!write(*,*)outputfile
Open(9, file=inputdatafile, status='old')
call linesFile(inputdatafile,n)
write(*,*)n
do i=1,n
read(*,*),command(i)
write (*,*)command(i)
end do
close(9)
end program atom_test
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!! find the number of lines in a file
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
subroutine linesFile(fileIn,n)
implicit none
Character(len = 50) :: fileIn
integer, intent(out) :: n
! locals
integer :: iostatus, unit_read
real :: dummy
unit_read = 9
open(unit=unit_read, file=fileIn)
n =0
DO
READ(unit_read, *, IOSTAT=iostatus) dummy
IF (iostatus < 0) EXIT
n = n + 1
END DO
! WRITE(*, '(i8, a, a)') n, ' bins read from file: ', fileIn
close(unit_read)
end subroutine linesFile
Given marked answer works fine. As I am very new in Fortran I have one more question related this. I want to get the elements separately from the ATOM rows in my data file for example: ATOM 1 S2 LJ2 1 17.000 15.030 11.630 1.00 0.00
from here i want to store 1,s2,LJ2,1,17.000,15.030 each in different parameters. In that case I am using this
/* With the code marked as correct
ncount=0
do i = 1, n
IF (command(i)(1:4).eq.'ATOM') THEN
ncount=ncount+1
read(read_unit,*) p, p2, p3,p4,xatom(ncount)
write(*,*),p
endif
end do
But it is not working.Can you please give me one suggestion about how to read individually from those lines which starts with ATOM? Thanks in advance!
493
How do I read an entire line in Fortran? The line read(*, *) command(i) reads the first element of standard input, not from the file. Actually, you'll probably want to read(9, '(A)') because you want to read the whole line, not just until the first element separator (i.e. space or comma).
open (unit = 24, file = "c:\\fortran\\data\\divisors. dat") . Fortran uses the unit number to access the file with later read and write statements. Several files can be open at once, but each must have a different number.
It is not possible. Reading always starts from a certain point, and proceeds forward. By default it starts from the first byte; but you can jump to some other location. The critical issue is, in a free-format file, there is no way to know where the lines start unless you read the file.
An IOSTAT value is a value assigned to the variable for the IOSTAT= specifier if an end-of-file condition, end-of-record condition or an error condition occurs during an input/output statement. There are five types of error conditions: catastrophic, severe, recoverable, conversion, Fortran 90 and Fortran 95 language.
There are a few things I notice straight away:
read(*, *) command(i) reads the first element of standard input, not from the file. I think you want to read(9, *).read(9, '(A)') because you want to read the whole line, not just until the first element separator (i.e. space or comma).In your subroutine, you open the file again, under the same unit. That is... dangerous if not wrong. Better to just read from the file, then use the rewind command to move the read position back to the beginning of the file.
program atom_test
implicit none
integer :: ios
integer, parameter :: read_unit = 99
character(len=200), allocatable :: command(:)
character(len=200) :: line
integer :: n, i
open(unit=read_unit, file='data.dat', iostat=ios)
if ( ios /= 0 ) stop "Error opening file data.dat"
n = 0
do
read(read_unit, '(A)', iostat=ios) line
if (ios /= 0) exit
n = n + 1
end do
print*, "File contains ", n, "commands"
allocate(command(n))
rewind(read_unit)
do i = 1, n
read(read_unit, '(A)') command(i)
end do
close(read_unit)
do i = 1, n
print*, command(i)
end do
end program atom_test
If you already dedicate 3000 lines in the beginning, there's no real reason to read everything twice:
program atom_test
implicit none
integer :: ios
integer, parameter :: read_unit = 99
character(len=200) :: command(3000)
integer :: n, i
open(unit=read_unit, file='data.dat', iostat=ios)
if ( ios /= 0 ) stop "Error opening file data.dat"
n = 0
do
read(read_unit, '(A)', iostat=ios) command(n+1)
if (ios /= 0) exit
n = n + 1
end do
print*, "File contains ", n, "commands"
close(read_unit)
do i = 1, n
print*, command(i)
end do
end program atom_test
In your subroutine to read the number of lines in the file, you try to read a REAL from a file where the first word is often not a number. This might lead to IOSTAT being non-zero, even if you haven't reached the end of the file. Always read a character variable.
180
This post provides an answer to OP comment:
I want to get the elements separately from the ATOM rows in my data file
Assuming input.txt looks like:
ATOM 1 S2 LJ2 1 17.000 15.030 11.630 1.00 0.00
ATOM 2 S2 LJ2 2 13.290 11.340 15.900 1.00 0.00
ATOM 3 S2 LJ2 3 17.030 23.070 14.750 1.00 0.00
ATOM 4 S2 LJ2 4 15.360 14.840 9.480 1.00 0.00
ATOM 5 S2 LJ2 5 15.780 4.560 9.580 1.00 0.00
ATOM 6 S2 LJ2 6 5.350 22.490 11.110 1.00 0.00
ATOM 7 S2 LJ2 7 19.940 3.910 10.840 1.00 0.00
ATOM 8 S2 LJ2 8 20.380 13.360 15.680 1.00 0.00
ATOM 9 S2 LJ2 9 18.340 4.200 7.720 1.00 0.00
ATOM 10 S2 LJ2 10 18.610 16.530 9.910 1.00 0.00
You could
program fort
integer n, i
parameter (n=10)
real r1(n), r2(n), r3(n), r4(n), r5(n), r6(n), r7(n)
character(len=255) format, s1(n), s2(n), s3(n), s4(n), s5(n),
& s6(n), s7(n), s8(n), s9(n), s10(n)
i=1
open(unit=99, file='input.txt')
2 read(99,3,end=1) s1(i), s2(i), s3(i), s4(i), s5(i),
& s6(i), s7(i), s8(i), s9(i), s10(i)
i=i+1
goto 2
3 format(a6,2a4,a5,a4,3a8,a6,a4)
4 format(a6,f4.1,2x,2a4,f4.1,5f8.3)
1 close(99)
read(s2,*) r1
read(s5,*) r2
read(s6,*) r3
read(s7,*) r4
read(s8,*) r5
read(s9,*) r6
read(s10,*) r7
do i=1,n
write(*,4) s1(i), r1(i), s3(i), s4(i), r2(i),
& r3(i), r4(i), r5(i), r6(i), r7(i)
enddo
end
output:
ATOM 1.0 S2 LJ2 1.0 17.000 15.030 11.630 1.000 0.000
ATOM 2.0 S2 LJ2 2.0 13.290 11.340 15.900 1.000 0.000
ATOM 3.0 S2 LJ2 3.0 17.030 23.070 14.750 1.000 0.000
ATOM 4.0 S2 LJ2 4.0 15.360 14.840 9.480 1.000 0.000
ATOM 5.0 S2 LJ2 5.0 15.780 4.560 9.580 1.000 0.000
ATOM 6.0 S2 LJ2 6.0 5.350 22.490 11.110 1.000 0.000
ATOM 7.0 S2 LJ2 7.0 19.940 3.910 10.840 1.000 0.000
ATOM 8.0 S2 LJ2 8.0 20.380 13.360 15.680 1.000 0.000
ATOM 9.0 S2 LJ2 9.0 18.340 4.200 7.720 1.000 0.000
ATOM 10.0 S2 LJ2 10.0 18.610 16.530 9.910 1.000 0.000
A better approach consists on
program fort
integer n, i
parameter (n=10)
integer i1(n), i2(n)
real r1(n), r2(n), r3(n), r4(n), r5(n)
character(len=255) format, s1(n), s2(n), s3(n), s4(n), s5(n),
& s6(n), s7(n), s8(n), s9(n), s10(n)
i=1
open(unit=99, file='input.txt')
2 read(99,3,end=1) s1(i), i1(i), s3(i), s4(i), i2(i),
& r1(i), r2(i), r3(i), r4(i), r5(i)
i=i+1
goto 2
3 format(a6,i4,a4,a5,i4,3f8.3,2f6.2)
4 format(a6,i4,2x,2a4,i4,5f8.3)
1 close(99)
do i=1,n
write(*,4) s1(i), i1(i), s3(i), s4(i), i2(i),
& r1(i), r2(i), r3(i), r4(i), r5(i)
enddo
end
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