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I tried to write some data in Fortran:
program Problem
DIMENSION X(8), W(8)
DATA X /0.0950125098D0, 0.2816035507D0, 0.4580167776D0, 0.6178762444D0
+ , 0.7554044083D0, 0.8656312023D0, 0.9445750230D0, 0.9894009349D0/
DATA W /0.1894506104D0, 0.1826034150D0, 0.1691565193D0, 0.1495959888D0
+ , 0.1246289712D0, 0.0951585116D0, 0.0622535239D0, 0.0271524594D0/
D = 0.D0
DO NJ=1,8
D = D + X(NJ) + W(NJ)
ENDDO
write(*,*) D
end
But I always get the following error message: Unexpected attribute declaration statement at (1).
Does anybody know why?
As already stated by others you should use the new fortran standard. If you do that you can just remove the "+" you used to indicate a continuation line (should have been in column 6) and instead add an ampersand "&" at the end of the line that should be continued.
Then the program compiles and runs. But as X and W are single precision you use too many digits in your data statement. Use implicit none and declare all variables. And get a textbook.
Below you find a minor update to your code which allows it to compile:
program Problemless
dimension X(8), W(8)
data X /0.0950125098D0, 0.2816035507D0, 0.4580167776D0,
+ 0.6178762444D0, 0.7554044083D0, 0.8656312023D0,
+ 0.9445750230D0, 0.9894009349D0/
data W /0.1894506104D0, 0.1826034150D0, 0.1691565193D0,
+ 0.1495959888D0, 0.1246289712D0, 0.0951585116D0,
+ 0.0622535239D0, 0.0271524594D0/
D = 0.D0
do NJ=1,8
D = D + X(NJ) + W(NJ)
enddo
write(*,*) D
end
Your code is written in Fixed-source form (See Section 6.3.3 of the Fortran standard). This implies that you cannot have anything beyond column 72. All I've done is to correct this in the above.
If you are learning fortran, I would suggest to stop using the fixed format and start using the free format.
no upvotes required for this post
I am working on a program to calculate minimum nozzle length in supersonic nozzles (Method of Characteristics). I can't seem to figure out why my code won't write to my output file (the lines "write (6,1000)....). My code is below:
program tester
c----------------------------------------------------------------------c
implicit real (a-h,o-z)
integer count
real kminus(0:100),kplus(0:100),theta(0:100),nu(0:100),mach(0:100)
+ ,mu(0:100)
open (5,file='tester.in')
open (6,file='tester.out')
read (5,*) me
read (5,*) maxturn
read (5,*) nchar
read (5,*) theta0
close(5)
c.....set count to 0 and calculate dtheta
count=0
dtheta=(maxturn-theta0)/nchar
c.....first characteristic
do 10 an=1,nchar+1
count=count+1
c........these are already known
theta(count)=theta0+dtheta*(an-1)
nu(count)=theta(count)
c........trivial, but we will "calculate" them anyways
kminus(count)=2*theta(count)
kplus(count)=0
c........we feed it nu(count) and get m out
call pm_hall_approx(nu(count),m)
mach(count)=m
c........does not work with sqrt(...) for some reason
mu(count)=atan((1/(mach(count)**2)-1)**0.5)
write (6,1000) count,kminus(count),kplus(count),theta(count)
+ ,nu(count),mach(count),mu(count)
10 continue
c.....the other characteristics
do 30 bn=1,nchar
do 20 cn=1,(nchar+1-bn)
count=count+1
c...........these are given
kminus(count)=kminus(cn+bn)
kplus(count)=-1*kplus(bn+1)
c...........if this is the last point, copy the previous values
if (cn.eq.(nchar+1-bn)) then
kminus(count)=kminus(count-1)
kplus(count)=kplus(count-1)
endif
c...........calculate theta and nu
theta(count)=0.5*(kminus(count)+kplus(count))
nu(count)=0.5*(kminus(count)-kplus(count))
c...........calculate m
call pm_hall_approx(nu(count),m)
mach(count)=m
mu(count)=atan((1/(mach(count)**2)-1)**0.5)
write (6,1000) count,kminus(count),kplus(count),theta(count)
+ ,nu(count),mach(count),mu(count)
20 continue
30 continue
close(6)
stop
1000 format (11(1pe12.4))
end
c======================================================================c
include 'pm_hall_approx.f'
And my subroutine is given here:
subroutine pm_hall_approx(nu,mach)
c----------------------------------------------------------------------c
c Given a Mach number, use the Hall Approximation to calculate the
c Prandtl-Meyer Function.
c----------------------------------------------------------------------c
implicit real (a-h,o-z)
c.....set constants
parameter (a=1.3604,b=0.0962,c=-0.5127,d=-0.6722,e=-0.3278)
parameter (numax=2.2769)
y=nu/numax
mach=(1+a*y+b*y*y+c*y*y*y)/(1+d*y+e*y*y)
return
end
And here are the contents of tester.in
2.4 = mache
5.0 = maxturn
7 = nchar
0.375 = theta0
In fortran, unit number 6 is reserved for screen. Never use that as the unit number. Try changing it to some other number like write(7,1000) and then it should work.
I am currently writing a code to simulate particle collisions. I am trying to open as much files as there are particles (N) and then put the data for positions and velocities in each of these files for each step of the time integration (using Euler's method, but that is not relevant). For that, I tried using a do loop so it will open all the files I need - then I put all the data in them with a different do loop later - and then close them all.
I first tried just doing a do loop to open the files - but it gave errors of the type "file already open in another unit", so I did the following:
module parameters
implicit none
character :: posvel
integer :: i, j, N
real :: tmax
real, parameter :: tmin=0.0, pi=3.14159265, k=500.0*10E3, dt=10.0E-5, dx=10.0E-3, g=9.806, ro=1.5*10E3
real, dimension(:), allocatable :: xold, xnew, vold, vnew, m, F, r
end module parameters
PROGRAM Collision
use parameters
implicit none
write(*,*) 'Enter total number of particles (integer number):'
read(*,*) N
allocate(xold(N))
allocate(vold(N))
allocate(xnew(N))
allocate(vnew(N))
allocate(m(N))
allocate(F(N))
allocate(r(N))
xold(1) = 0.0
vold(1) = 0.0
m(1) = 6.283*10E-9
r(1) = 10E-4
xold(2) = 5.0
vold(2) = 0.0
m(2) = 6.283*10E-9
r(2) = 10E-4
write(*,*) 'Type total time elapsed for the simulation(real number):'
read(*,*) tmax
do i = 1, N
write(posvel,"(a,i3.3,a)") "posveldata",i,".txt"
open(unit=i,file=posvel, status="unknown")
end do
do i = 1, N
close(unit=i)
end do
END PROGRAM Collision
The last ten lines are the ones that regard to my problem.
That worked in codeblocks - it opened just the number of files I needed, but I'm actually using gfortran and it gives me and "end of record" error in the write statement.
How can I make it to execute properly and give me the N different files that I need?
P.S.: It is not a problem of compilation, but after I execute the program.
Your character string in the parameter module has only 1 character length, so it cannot contain the full file name. So please use a longer string, for example
character(100) :: posvel
Then you can open each file as
do i = 1, N
write(posvel,"(a,i0,a)") "posveldata",i,".txt"
open(unit=i,file=trim(posvel), status="unknown")
end do
Here, I have used the format i0 to automatically determine a proper width for integer, and trim() for removing unnecessary blanks in the file name (though they may not be necessary). The write statement can also be written more compactly as
write(posvel,"('posveldata',i0,'.txt')") i
by embedding character literals into the format specification.
The error message "End of record" comes from the above issue. This can be confirmed by the following code
character c
write(c,"(a)") "1"
print *, "c = ", c
write(c,"(a)") "23" !! line 8 in test.f90
print *, "c = ", c
for which gfortran gives
c = 1
At line 8 of file test.f90
Fortran runtime error: End of record
This means that while c is used as an internal file, this "file" does not have enough space to accommodate two characters (here "23"). For comparison, ifort14 gives
c = 1
forrtl: severe (66): output statement overflows record, unit -5, file Internal Formatted Write
while Oracle Fortran12 gives
c = 1
****** FORTRAN RUN-TIME SYSTEM ******
Error 1010: record too long
Location: the WRITE statement at line 8 of "test.f90"
Aborted
(It is interesting that Oracle Fortran reports the record to be "too long", which may refer to the input string.)
I would like to read a sequence of integer in a line with unknown bound in FORTRAN. My question is similar to the following previous post,
Reading a file of lists of integers in Fortran
however I want to read a sequence of unknown numbers of integer in a line and save it in separate arrays. And successive lines of integer should be saved to some other array
My file looks like this
5 7 8 9 10 13 # should be stored f(1)(6) arrays
93 102 92 # c(1)(3)
105 107 110 145 147 112 # f(2)(6)
97 98 # b(1)(2)
12 54 55 # c(2)(3)
15 17 21 23 45 # e(1)(5)
43 47 48 51 62 # d(1)(4)
Thus I have a sequence of integers with maximum length of 6 (to be stored in f array) and minimum length of 2(to be stored in b array). I have hundreds of lines like this, such that I need to classify according to the maximum length and count on them.
Reading a file of lists of integers in Fortran
There are probably many ways to do this, and the following is one such example. Here, the split() makes multiple trials for list-directed input for all values in the line, until non-numeric characters or the end of line is encountered.
subroutine split( line, vals, n )
implicit none
character(*), intent(in) :: line
real*8 :: vals(*), buf( 100 ) !! currently up to 100 items (for test)
integer :: n
n = 1
do
read( line, *, end=100, err=100 ) buf( 1 : n ) !! (See Appendix for why buf is used here)
vals( 1:n ) = buf( 1:n )
n = n + 1
enddo
100 continue
n = n - 1
end
program main
implicit none
character(200) :: line
real*8 :: vals( 100 )
integer :: n
open( 10, file="test.dat", status="old" )
do
read( 10, "(a)", end=500 ) line
call split( line, vals, n )
if ( n == 0 ) then
print *, "comment line"
else
print *, nint( vals( 1 : n ) )
endif
enddo
500 continue
close( 10 )
end
If test.dat contains the whole lines in the Question, plus the following lines
# additional data
1,2,3 , 4 , 5 # comma-separated integers
1.23e2 -4.56e2 , 777 # integer/floating-point mixed case
it gives
comment line
5 7 8 9 10 13
93 102 92
105 107 110 145 147 112
97 98
12 54 55
15 17 21 23 45
43 47 48 51 62
comment line
1 2 3 4 5
123 -456 777
So one can save the result for each line by copying the values in vals(1:n) to a desired array.
[ Appendix (thanks to #francescalus) ]
In the above code, the data are read once into buf(1:n) and then copied to vals(1:n). One might think that it would be more direct to read in the data into vals(1:n) such that
read( line, *, end=100, err=100 ) vals( 1 : n )
However, this direct approach is not recommended because vals(1:n) becomes undefined when the read statement hits the "end" or "err" condition. Although ifort and gfortran seem to retain the data in vals(1:n) even when that condition is met (and so they work even with the direct approach), the same behavior cannot be guaranteed for other compilers. In contrast, the buffer approach avoids this risk by saving the data one step before to vals(1:n), so that undefined data are not used. This is why the buffer approach is used in the above code despite it is one statement longer.
Something like this might satisfy your requirements
INTEGER :: ix, rdstat
INTEGER, DIMENSION(6) :: nums
CHARACTER(len=128) :: aline
...
OPEN(21,file='data.txt')
DO ix = 1,10
READ(21,'(a)',iostat=rdstat) aline
IF (rdstat/=0) catch_errors()
nums = -99 ! a guard
READ(aline,*,iostat=rdstat) nums
IF (rdstat/=0) catch_errors()
! do something with nums
END DO
CLOSE(21)
I haven't thoroughly tested this and I haven't written catch_errors for you -- in practice you may not want to do very much. This first version is probably too brittle, but whether it's suitable or not depends heavily on the uniformity (or otherwise) of the input files.
The strategy is to read each line into a character variable (one long enough for the entire line) and then to use internal, list-directed, reading to read 6 integers from the start of the character variable. This takes advantage of the in-built facility that list-directed input has of finding integers in an input stream with spaces separating values. The approach should work as well with a comma-separated list of integers. The internal read only looks for 6 integers, then catches the error when either no more integers are found, or only material which cannot be interpreted as integers (such as strings like # comment).
Note
I've assumed a maximum line length of 128 characters, you may want to adjust that.
I've specified a fixed upper limit on the number of lines the program will read. You may want to change that, or change to a do/while loop.
The program expects no more than 6 integers in a line, as your question specifies.
At each line read the array nums is filled with -99 at each element; this is a 'guard'. If -99 is likely to occur in your input files you may want to change this.
It's entirely up to you what you do with the numbers in nums once you have them.
I am trying to use the code below to read a formatted file and write it into another. However, on running it shows the following error
$ ./conv.sac.farm < i_conv.farm
# stn comp Delta Tr-time Start in record
At line 54 of file Main/conv.sac.farm.f (unit = 5, file = 'stdin')
Fortran runtime error: Bad real number in item 1 of list input
The source code is as follows
PARAMETER (nd0=100000,pi=3.1415926)
IMPLICIT COMPLEX*8 (Z)
CHARACTER name*6,comp*6,fname*60,event*20
- ,cmp(0:3)*5,fname0*60,charac*15,scode*60
REAL*8 GFACT(500),PP0(500),depth0
integer hr0,mnu0,yr,month,day,hr,mnu
REAL x(nd0),y(nd0)
DIMENSION Z(nd0),zpole(50),zero(50)
data np,cmp/8,'disp.','vel. ','acc. ','orig.'/
common /tbl/ip(110,14),is(110,14),secp(110,14),secs(110,14)
read(5,'(a)') event
read(5,*) alats,alons,depth,hr0,mnu0,sec0,id,delmin,delmax
depth0=depth
write(22,'(a,a5,3f7.2,2i3,f6.2)')
# event,cmp(id),alats,alons,depth,hr0,mnu0,sec0
* << J-B travel time table >>
OPEN(11,FILE='jb.ptime')
OPEN(12,FILE='jb.stime')
1000 read(11,*,end=1001) n,(ip(n,i),secp(n,i),i=1,14)
goto 1000
1001 read(12,*,end=1002) n,(is(n,i),secs(n,i),i=1,14)
goto 1001
1002 continue
close(11)
close(12)
* << Geometrical factor >>
OPEN(15,FILE='jb.table')
CALL GEOM(GFACT,PP0,depth0)
close(15)
nstn=0
print *,' # stn comp Delta Tr-time Start in record'
5 read(5,'(a)') fname
read(5,'(a)') scode
* ta=advance of start-time relative the standard P/S arrival
* du=duration
c
if(fname.eq.'dummy') goto 90
read(5,*) ta,du,dt,f1,f2,iph,nr,iuni
open(1,file=fname)
READ(1,'(g15.7)') dt0
read(1,'(/////5g15.7)') dum, alat, alon, elev
read(1,'(///////5i10)') yr, nday, hr,mnu, nsec
read(1,'(5i10)') nmsec,ndum,ndum,ndum,nd
read(1,'(/////)')
read(1,'(a6,2x,a13)') name,charac
read(1,'(////)')
And so on..
Line 54 is
read(5,*) ta,du,dt,f1,f2,iph,nr,iuni
I found a similar question following this link
Fortran runtime error: Bad real number
However, if I understand correctly, the corrections mentioned were pertaining to reading unformatted data. Despite this, I tried and failed as expected, given that the file I am trying to read is formatted.
here is a little trick if you can't readily find the offending line in the data file:
replace your read that throws the error with this:
read(5,'(a)')line
read(line,*,iostat=ios) ta,du,dt,f1,f2,iph,nr,iuni
if(ios>0)then
write(*,*)'error reading line:',line
stop
endif
with the declarations
integer ios
character*(200) line
Probably just do that for debugging then revert to the original once you fix the problem.