fortran files in Microsoft Visual Studio

Rositta

I'm new to Microsoft Visual Studio (2010) & I'm a bit confused by the way Visual Studio handles fortran files. I saved a set of data in one console and tried to read the data from the created file in another console. I receive the next message:

file opened correctly!
forrt1: severe<24>: end-of-file during read, unit 1, file C:\Doculents and settings\.......

I've tried to save the data as .dat and .txt and the message remained the same. The funny thing is that I can read the saved .txt and .dat files in Matlab!

Does anyone know why I receive this message?

TheoMcCloskey

Sounds like your trying to read past the end-of-file during your input. Try using the END option within your READ statement.

Rositta

Thanks a lot TheoMcCloskey. I have done some searching to fully understand the function of the END specifier with little success. Could you please expand a bit on the use of END?????

jtbell

The statement

READ (10, 50, END=200) X

says: "Try to read the variable X from unit 10 using format statement 50. If you hit the end of the file while trying to read X, jump to statement 200."

In order for this to work, of course, you have to put statement number 200 on the statement that you want to pick up execution from when you reach the end of the file.

Rositta

Thanks a lot for the quick answer.. I'll see if that will solve the problem..

Rositta

Well.. the file is still unread.. I think I should post the codes=>

=>The program I used to create the data is

program xytable
! this code is to create data for the interpolation code written in console12
implicit none
integer::i,j
integer,parameter::m=50
real,dimension(1:m)::t,h
real,dimension(m,2)::A ! a 2D matrix to store x & y


!create data
do i=1,m
t(i)=(i*1.-1.)/2.
h(i)=f(t(i))
A(i,1)=t(i)
A(i,2)=h(i)
end do

!save data
open(1,file='xytable.txt')
do i=1,m
print*,(A(i,j),j=1,2)
write(1,*)(A(i,j),j=1,2)
end do
close(1)



!define function f(x)
contains
function f(t)
real::f,t
f=2*t**2-t
end function f

end program xytable


The data as appear in the text file are:

0.0000000E+00 0.0000000E+00
0.5000000 0.0000000E+00
1.000000 1.000000
1.500000 3.000000
2.000000 6.000000
2.500000 10.00000
3.000000 15.00000
3.500000 21.00000
4.000000 28.00000
4.500000 36.00000
5.000000 45.00000
5.500000 55.00000
6.000000 66.00000
6.500000 78.00000
7.000000 91.00000
7.500000 105.0000
8.000000 120.0000
8.500000 136.0000
9.000000 153.0000
9.500000 171.0000
10.00000 190.0000
10.50000 210.0000
11.00000 231.0000
11.50000 253.0000
12.00000 276.0000
12.50000 300.0000
13.00000 325.0000
13.50000 351.0000
14.00000 378.0000
14.50000 406.0000
15.00000 435.0000
15.50000 465.0000
16.00000 496.0000
16.50000 528.0000
17.00000 561.0000
17.50000 595.0000
18.00000 630.0000
18.50000 666.0000
19.00000 703.0000
19.50000 741.0000
20.00000 780.0000
20.50000 820.0000
21.00000 861.0000
21.50000 903.0000
22.00000 946.0000
22.50000 990.0000
23.00000 1035.000
23.50000 1081.000
24.00000 1128.000
24.50000 1176.000




=>The program I am reading the data in is:

program readtext
implicit none

!interface between main program and subroutine
interface
subroutine polint(x,y,xin,yout,dyout)
use nrtype
real(sp),dimension(:),intent(in)::x,y
real(sp),intent(in)::xin
real(sp),intent(out)::yout,dyout
end subroutine polint
end interface

!declare variables
real,allocatable,dimension(:)::x,y
real::xin,yout,dyout,t,h
integer::p,st,row,col
integer,parameter::n=50
real,dimension(n,2)::A


!make memory for the input x and y arrays
if(allocated(x)) then
deallocate(x)
end if
if(allocated(y))then
deallocate(y)
end if
allocate(x(1:n),y(1:n),stat=p)
if(p /= 0) then
print*,"allocation error"
stop
end if


!load data into the code
open(unit=1,file='xytable.txt',form='formatted',iostat=st)
if(st/=0)then
print*,'Error opening file. File load status=',st
stop
else
print*,'file opened correctly!.ios=',st
end if

do row = 1,n
read(1,*,end=50)(A(row,col),col=1,2)
end do

50 do row = 1,n
print*,(A(row,col),col=1,2)
end do

print*, "dimension of x and y arrays="
print*,n

end program readtext

I reach the statement '50' but all the numbers in both columns are zeros. I've been advised to change the read loop to:

read(1,*,end=50) A(row,:)
read(1,*,end=50) A(row,1),A(row,2)

but the result is unchanged.. I really can't see where the problem lies.

TheoMcCloskey

Rositta,

I was able to sucessfully run this (without interface to polint) but I had to make one change in your open statement within READTEXT program; change "io stat" to "iostat".

I used gfortran (gcc ver 4.3 20070522) on Windows XP.

Rositta

Thanks TheoMcCloskey. It is "iostat" in my original code. Apparently I made a mistake during pasting the code. I still have the problem of getting zero valued entities instead of the saved numbers.

TheoMcCloskey

I'm not sure what else to say. Your program "XYTABLE" does produce the required 50 lines of data, 2 per line, no delimiter, spaced separated.

The very fact that your original problem suggested reading past the end-of-file (EOF) has me suspicious. I did not have that problem. The program should not require the read statement “END” option in this particular case. I’ve modified the program “READTEXT” as shown below to print a message if, in fact, it does try to read past EOF (see listing below). Try it and let me know.

Are you sure you are connected to data file? What does your print message flag report (variable “st”).

Rositta

Hi TheoMcCloskey.. I've tried the modification with no change in the output. I do have a data file which I can read in Matlab as I mentioned in my first post. The flag report gives st=0. I found another Physics Forum thread talking about the same problem:
http://www.physicsforums.com/showthread.php?t=307269
Could it be a compiler problem???

Rositta

well.. the code worked with no problems at all in gfortran..