Compilation program to read NetCDF file with fortran90
i_want_to_love_...@hotmail.com
I want to read and write files in NetCDF, so at first I am going to
read values of files written in NetCDF.
The file to read is below.
*********************************************
implicit none
include 'netcdf.inc'
integer :: ncid,status,varid
real,dimension(100,100,26) :: UDATA
!real,dimension(99,99,27) :: WDATA
status = NF_OPEN ('wrfout_d01_2006-01-01_00:00:00',0,ncid)
if (status .ne. NF_NOERR) call HANDLE_ERR(STATUS)
status = nf_inq_varid (ncid, "U", varid)
if (status .ne. NF_NOERR) then
write(6,*) "VAR ERROR"
stop
endif
status = nf_get_var_real (ncid,varid,UDATA)
if(status .ne. NF_NOERR) then
write(6,*) "READ ERROR"
stop
endif
status = nf_close(ncid)
write(6,*) ncid,varid
stop
end
*************************************************
And then, I typed
$ ifort -c -I/usr/local/netcdf-3.6.2/include 1st.f90
$ ifort -lnetcdf -L/usr/local/netcdf-3.6.2/lib 1st.o -o a.out
Then, I got these errors.
[C@localhosts netcdf]$ ifort -lnetcdf -L/usr/local/netcdf-3.6.2/lib
1st.o -o a.out
1st.o: In function `MAIN__':
1st.f90:(.text+0x46): undefined reference to `nf_open_'
1st.f90:(.text+0x76): undefined reference to `nf_inq_varid_'
1st.f90:(.text+0xa1): undefined reference to `nf_get_var_real_'
1st.f90:(.text+0x11a): undefined reference to `nf_close_'
1st.f90:(.text+0x30a): undefined reference to `handle_err_'
If you know something about these errors, please give me information
anything you have.
Hiroshi
Arjen Markus
You should probably change the order of the arguments:
ifort -L/usr/local/netcdf-3.6.2/lib -lnetcdf 1st.o -o a.out
and you need additional libraries. Here is a compile/link command I
use
myself:
ifort -o program program.f90 -Inetcdf-4.0/f90 netcdf-4.0/f90/.libs/
libnetcdff90.a netcdf-4.0/fortran/.libs/libnetcdff.a netcdf-4.0/
libsrc/.libs/libnetcdf.a
Not the most efficient perhaps, but for my particular case it works.
As you can see you need a few more libraries.
Regards,
Arjen
Dave Allured
You are trying to use the Netcdf F77 interface. You can make it work,
but I recommend the F90 interface instead, since your main program is
F90. See the Netcdf on-line documentation for the Fortran 90 API.
Also, check with your system administrator to make sure that the F90
interface is installed. It is an optional part of Netcdf. In
particular, make sure that the file netcdf.mod is available and
specified on your compile command line.
--Dave
Paul van Delst
Not for v3.6.2 he doesn't. You're using netCDF v4.0.
To the OP: Once you solve your link problems, why not try using the Fortran90 API to netCDF?
As an aside, I've been thinking about upgrading to v4.0 but the reason I use netCDF (as
opposed to, say, HDF) is that netCDF is simple (both the library build and usage). If the
above explosion of required libraries to use netCDF v4.0 is true, I may stick with the old
version (netCDF v3.6.x).
cheers,
paulv
i_want_to_love_...@hotmail.com
For everyone, thanks for your attention.
The file I want to read is made by WRF (Weather Research and
Forecasting) model.
I built up WRF with NetCDF, and both were compiled with ifort and icc.
Can I use only F77 interface with default setting?
Hiroshi
i_want_to_love_...@hotmail.com
For everyone, thanks for your attention.
Dave Allured
Yes, you should be able to use only F77 interface. Based on your
original post, I think you have at least three specific problems. Arjen
addressed two of them, I will try to explain:
1. -lnetcdf should be positioned to the right of the -L option.
2. You may need a second library libnetcdff. Try adding -lnetcdff to
your command.
3. handle_error is a user-supplied subroutine. Just insert this after
the end of your main program (untested):
subroutine handle_error (status)
implicit none
integer, intent (in) :: status
print *, 'Netcdf error number = ', status
stop
end subroutine handle_error
Here is a modification of your original compile commands. Only the
second line is changed:
ifort -c -I/usr/local/netcdf-3.6.2/include 1st.f90
ifort -L/usr/local/netcdf-3.6.2/lib -lnetcdf -lnetcdff 1st.o -o a.out
First try this without -lnetcdff . If you still get the missing symbol
errors for nf_open_ etc., then add -lnetcdff . You may need to search
all file names under /usr/local/netcdf-3.6.2 to find this library, and
add a second -L command to give its correct path if different than the
one in the first -L option.
I am unsure about libnetcdff because they changed the Fortran API
library configuration somewhere around version 3.6.2 or 3.6.3. The
Fortran library was split off into the separate library libnetcdff.
This is further complicated by a newly introduced configure option to
build the Fortran libraries either way. I do not have all the details
memorized. ;-)
You can examine the Netcdf library file(s) yourself to locate symbols
like nf_open_ which are part of the F77 interface. Something like this,
it may vary between platforms:
cd /usr/local/netcdf-3.6.2/lib
nm libnetcdf* | grep nf_open_
If you can't figure this out here in c.l.f., then try the Netcdf users
list. They are very helpful.
--Dave
TideMan
I've just been through the process of setting up read/write of netCDF
files using gfortran on Ubuntu 8.04.
First, I downloaded netCDF 4.0 sources, then CDed to the directory
and:
./configure
make
sudo su
make install
This generated and installed a static library in /usr/local/lib
Now to compile and link Test.f90 I do this:
gfortran -o Test Test.f90 /usr/local/lib/libnetcdf.a