eccodes/examples/F90/grib_samples.f90

96 lines
2.8 KiB
Fortran

! (C) Copyright 2005- ECMWF.
!
! This software is licensed under the terms of the Apache Licence Version 2.0
! which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
!
! In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
! virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
!
!
! Description: How to create a new GRIB message from a sample.
!
program sample
use eccodes
implicit none
integer :: err
integer :: outfile, datafile
integer :: igribsample, igribclone, igribdata, size1
integer :: date1, startStep, endStep, table2Version, indicatorOfParameter
integer :: decimalPrecision
character(len=10) stepType
real(kind=8), dimension(:), allocatable :: v1, v2, v
date1 = 20080104
startStep = 0
endStep = 12
stepType = 'accum'
table2Version = 2
indicatorOfParameter = 61
decimalPrecision = 2
! A new GRIB message is loaded from an existing sample.
! Samples are searched in a default sample path (use codes_info
! to see where that is). The default sample path can be changed by
! setting the environment variable ECCODES_SAMPLES_PATH
call codes_grib_new_from_samples(igribsample, "regular_latlon_surface.grib1")
call codes_open_file(outfile, 'f_out.samples.grib1', 'w')
call codes_open_file(datafile, '../../data/tp_ecmwf.grib', 'r')
call codes_grib_new_from_file(datafile, igribdata, err)
call codes_get_size(igribdata, 'values', size1)
allocate (v(size1))
allocate (v1(size1))
allocate (v2(size1))
call codes_get(igribdata, 'values', v)
v = v*1000.0 ! different units for the output grib
v1 = v
do while (err /= CODES_END_OF_FILE)
call codes_clone(igribsample, igribclone) ! clone sample before modifying it
call codes_set(igribclone, 'dataDate', date1)
call codes_set(igribclone, 'table2Version', table2Version)
call codes_set(igribclone, 'indicatorOfParameter', indicatorOfParameter)
call codes_set(igribclone, 'stepType', stepType)
call codes_set(igribclone, 'startStep', startStep)
call codes_set(igribclone, 'endStep', endStep)
call codes_set(igribclone, 'decimalPrecision', decimalPrecision)
call codes_set(igribclone, 'values', v)
call codes_write(igribclone, outfile)
call codes_grib_new_from_file(datafile, igribdata, err)
if (err == 0) then
call codes_get(igribdata, 'values', v2)
v2 = v2*1000.0 ! different units for the output grib
v = v2 - v1 ! accumulation from startStep to endStep
v1 = v2 ! save previous step field
startStep = startStep + 12
endStep = endStep + 12
end if
end do
call codes_release(igribsample)
deallocate (v)
deallocate (v1)
deallocate (v2)
call codes_close_file(outfile)
end program sample