Create a group. Its location id is returned in new_ncid.
function nf90_def_grp(parent_ncid, name, new_ncid)
integer, intent(in) :: parent_ncid
character (len = *), intent(in) :: name
integer, intent(out) :: new_ncid
integer :: nf90_def_grp
PARENT_NCIDNAMENEW_NCIDNF90_NOERRNF90_EBADIDNF90_ENAMEINUSENF90_EMAXNAMENF90_EBADNAMENF90_ENOTNC4NF90_ESTRICTNC3NF90_EHDFERRNF90_EPERMNF90_ENOTINDEFINE C Create the netCDF file.
retval = nf90_create(file_name, NF90_NETCDF4, ncid)
if (retval .ne. nf90_noerr) call handle_err(retval)
C Create a group and a subgroup.
retval = nf90_def_grp(ncid, group_name, grpid)
if (retval .ne. nf90_noerr) call handle_err(retval)
retval = nf90_def_grp(grpid, sub_group_name, sub_grpid)
if (retval .ne. nf90_noerr) call handle_err(retval)