00001 ! Copyright 2005-2015 ECMWF
00002 ! This software is licensed under the terms of the Apache Licence Version 2.0
00003 ! which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
00004 !
00005 ! In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
00006 ! virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
00007 !
00008 !
00009 ! Description: how to set pv values.
00010 !
00011 !
00012 ! Author: Anne Fouilloux
00013 !
00014 !
00015 program set_pv
00016 use grib_api
00017 implicit none
00018 integer :: numberOfLevels
00019 integer :: numberOfCoefficients
00020 integer :: outfile, igrib
00021 integer :: i, ios
00022 real, dimension(:),allocatable :: pv
00023
00024 numberOfLevels=60
00025 numberOfCoefficients=2*(numberOfLevels+1)
00026
00027 allocate(pv(numberOfCoefficients))
00028
00029 ! read the model level coefficients from file
00030 open( unit=1, file="../../data/60_model_levels", &
00031 form="formatted",action="read")
00032
00033 do i=1,numberOfCoefficients,2
00034 read(unit=1,fmt=*, iostat=ios) pv(i), pv(i+1)
00035 if (ios /= 0) then
00036 print *, "I/O error: ",ios
00037 exit
00038 end if
00039 end do
00040
00041 ! print coefficients
00042 !do i=1,numberOfCoefficients,2
00043 ! print *," a=",pv(i)," b=",pv(i+1)
00044 !end do
00045
00046 close(unit=1)
00047
00048 call grib_open_file(outfile, 'out.grib1','w')
00049
00050 ! a new grib message is loaded from file
00051 ! igrib is the grib id to be used in subsequent calls
00052 call grib_new_from_samples(igrib, "reduced_gg_sfc_grib1")
00053
00054 ! set levtype to ml (model level)
00055 call grib_set(igrib,'levtype','ml')
00056
00057 ! set level
00058 call grib_set(igrib,'level',2)
00059
00060 ! set PVPresent as an integer
00061 call grib_set(igrib,'PVPresent',1)
00062
00063 call grib_set(igrib,'pv',pv)
00064
00065 ! write modified message to a file
00066 call grib_write(igrib,outfile)
00067
00068 ! FREE MEMORY
00069 call grib_release(igrib)
00070 deallocate(pv)
00071
00072 call grib_close_file(outfile)
00073
00074 end program set_pv
