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C This is part of the netCDF package.
C Copyright 2006 University Corporation for Atmospheric Research/Unidata.
C See COPYRIGHT file for conditions of use.
C This is a very simple example which writes a 2D array of
C sample data. To handle this in netCDF we create two shared
C dimensions, "x" and "y", and a netCDF variable, called "data".
C This program is part of the netCDF tutorial:
C http://www.unidata.ucar.edu/software/netcdf/docs/tutorial_8dox.html
C Full documentation of the netCDF Fortran 77 API can be found at:
C http://www.unidata.ucar.edu/software/netcdf/docs-fortran/nc_f77_interface_guide.html
C Ed Hartnett
program simple_xy_wr
implicit none
include 'netcdf.inc'
C This is the name of the data file we will create.
character*(*) FILE_NAME
parameter (FILE_NAME='simple_xy.nc')
C We are writing 2D data, a 12 x 6 grid.
integer NDIMS
parameter (NDIMS=2)
integer NX, NY
parameter (NX = 6, NY = 12)
C When we create netCDF files, variables and dimensions, we get back
C an ID for each one.
integer ncid, varid, dimids(NDIMS)
integer x_dimid, y_dimid
C This is the data array we will write. It will just be filled with
C a progression of integers for this example.
integer data_out(NY, NX)
C Loop indexes, and error handling.
integer x, y, retval
C Create some pretend data. If this wasn't an example program, we
C would have some real data to write, for example, model output.
do x = 1, NX
do y = 1, NY
data_out(y, x) = (x - 1) * NY + (y - 1)
end do
end do
C Always check the return code of every netCDF function call. In
C this example program, any retval which is not equal to nf_noerr
C (0) will call handle_err, which prints a netCDF error message, and
C then exits with a non-zero return code.
C Create the netCDF file. The nf_clobber parameter tells netCDF to
C overwrite this file, if it already exists.
retval = nf_create(FILE_NAME, NF_CLOBBER, ncid)
if (retval .ne. nf_noerr) call handle_err(retval)
C Define the dimensions. NetCDF will hand back an ID for each.
retval = nf_def_dim(ncid, "x", NX, x_dimid)
if (retval .ne. nf_noerr) call handle_err(retval)
retval = nf_def_dim(ncid, "y", NY, y_dimid)
if (retval .ne. nf_noerr) call handle_err(retval)
C The dimids array is used to pass the IDs of the dimensions of
C the variables. Note that in fortran arrays are stored in
C column-major format.
dimids(2) = x_dimid
dimids(1) = y_dimid
C Define the variable. The type of the variable in this case is
C NF_INT (4-byte integer).
retval = nf_def_var(ncid, "data", NF_INT, NDIMS, dimids, varid)
if (retval .ne. nf_noerr) call handle_err(retval)
C End define mode. This tells netCDF we are done defining metadata.
retval = nf_enddef(ncid)
if (retval .ne. nf_noerr) call handle_err(retval)
C Write the pretend data to the file. Although netCDF supports
C reading and writing subsets of data, in this case we write all the
C data in one operation.
retval = nf_put_var_int(ncid, varid, data_out)
if (retval .ne. nf_noerr) call handle_err(retval)
C Close the file. This frees up any internal netCDF resources
C associated with the file, and flushes any buffers.
retval = nf_close(ncid)
if (retval .ne. nf_noerr) call handle_err(retval)
print *,'*** SUCCESS writing example file simple_xy.nc!'
end
subroutine handle_err(errcode)
implicit none
include 'netcdf.inc'
integer errcode
print *, 'Error: ', nf_strerror(errcode)
stop 2
end
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