gen_be_cov2d.f90

References to this file elsewhere.
1 program gen_be_cov2d
2 
3    use da_control
4    use da_gen_be
5 
6    implicit none
7 
8    character*10        :: start_date, end_date       ! Starting and ending dates.
9    character*10        :: date, new_date             ! Current date (ccyymmddhh).
10    character*10        :: variable1					 ! Variable name
11    character*10        :: variable2					 ! Variable name
12    character(len=filename_len)        :: filename                   ! Input filename.
13    character*3         :: ce                         ! Member index -> character.
14    integer             :: ni, nj, nk, nkdum          ! Grid dimensions.
15    integer             :: i, j, member               ! Loop counters.
16    integer             :: b                          ! Bin marker.
17    integer             :: sdate, cdate, edate        ! Starting, current ending dates.
18    integer             :: interval                   ! Period between dates (hours).
19    integer             :: ne                         ! Number of ensemble members.
20    integer             :: bin_type                   ! Type of bin to average over.
21    integer             :: num_bins                   ! Number of bins (3D fields).
22    integer             :: num_bins2d                 ! Number of bins (3D fields).
23    real                :: lat_min, lat_max           ! Used if bin_type = 2 (degrees).
24    real                :: binwidth_lat               ! Used if bin_type = 2 (degrees).
25    real                :: hgt_min, hgt_max           ! Used if bin_type = 2 (m).
26    real                :: binwidth_hgt               ! Used if bin_type = 2 (m).
27    real                :: coeffa, coeffb             ! Accumulating mean coefficients.
28    logical             :: first_time                 ! True if first file.
29 
30    real, allocatable   :: latitude(:,:)              ! Latitude (degrees, from south).
31    real, allocatable   :: height(:,:,:)              ! Height field.
32    real, allocatable   :: field1(:,:)                ! Field 1.
33    real, allocatable   :: field2(:,:)	             ! Field 2.
34    integer, allocatable:: bin(:,:,:)                 ! Bin assigned to each 3D point.
35    integer, allocatable:: bin2d(:,:)                 ! Bin assigned to each 2D point.
36    integer, allocatable:: bin_pts2d(:)               ! Number of points in bin (2D fields).
37    real, allocatable   :: covar(:)                   ! Covariance between input fields.
38    real, allocatable   :: var(:)                     ! Autocovariance of field.
39 
40    namelist / gen_be_cov2d_nl / start_date, end_date, interval, &
41                                 ne, bin_type, &
42                                 lat_min, lat_max, binwidth_lat, &
43                                 hgt_min, hgt_max, binwidth_hgt, &
44                                 variable1, variable2
45 
46    integer :: ounit,iunit,namelist_unit
47 
48    stderr = 0
49    stdout = 6
50 
51 
52 !---------------------------------------------------------------------------------------------
53    write(6,'(a)')' [1] Initialize namelist variables and other scalars.'
54 !---------------------------------------------------------------------------------------------
55 
56 
57    call da_get_unit(ounit)
58    call da_get_unit(iunit)
59    call da_get_unit(namelist_unit)
60 
61 
62    start_date = '2004030312'
63    end_date = '2004033112'
64    interval = 24
65    ne = 1
66    bin_type = 1
67    lat_min = -90.0
68    lat_max = 90.0
69    binwidth_lat = 10.0
70    hgt_min = 0.0
71    hgt_max = 20000.0
72    binwidth_hgt = 1000.0
73    variable1 = 'ps_u'
74    variable2 = 'ps'
75 
76    open(unit=namelist_unit, file='gen_be_cov2d_nl.nl', &
77         form='formatted', status='old', action='read')
78    read(namelist_unit, gen_be_cov2d_nl)
79    close(namelist_unit)
80 
81    read(start_date(1:10), fmt='(i10)')sdate
82    read(end_date(1:10), fmt='(i10)')edate
83    write(6,'(4a)')' Computing covariance for fields ', variable1 , ' and ', variable2
84    write(6,'(4a)') ' Time period is ', start_date, ' to ', end_date
85    write(6,'(a,i8,a)')' Interval between dates = ', interval, 'hours.'
86    write(6,'(a,i8)')' Number of ensemble members at each time = ', ne
87 
88    date = start_date
89    cdate = sdate
90 
91 !---------------------------------------------------------------------------------------------
92    write(6,'(2a)')' [2] Read fields, and calculate correlations'
93 !--------------------------------------------------------------------------------------------- 
94 
95    first_time = .true.
96 
97    do while ( cdate <= edate )
98       write(6,'(a,a)')'    Processing data for date ', date
99 
100       do member = 1, ne
101 
102          write(ce,'(i3.3)')member
103 
104 !        Read Full-fields:
105          filename = 'fullflds/'//date(1:10)
106          filename = trim(filename)//'.fullflds.e'//ce
107          open (iunit, file = filename, form='unformatted')
108 
109          read(iunit)ni, nj, nk
110          if ( first_time ) then
111             write(6,'(a,3i8)')'    i, j, k dimensions are ', ni, nj, nk
112             allocate( latitude(1:ni,1:nj) )
113             allocate( height(1:ni,1:nj,1:nk) )
114             allocate( bin(1:ni,1:nj,1:nk) )
115             allocate( bin2d(1:ni,1:nj) )
116             allocate( field1(1:ni,1:nj) )
117             allocate( field2(1:ni,1:nj) )
118          end if
119          read(iunit)latitude
120          read(iunit)height
121 
122 !        Create and sort into bins:
123          call da_create_bins( ni, nj, nk, bin_type, num_bins, num_bins2d, bin, bin2d, &
124                               lat_min, lat_max, binwidth_lat, &
125                               hgt_min, hgt_max, binwidth_hgt, latitude, height )
126 
127          close(iunit)
128 
129          if ( first_time ) then
130             allocate( bin_pts2d(1:num_bins2d) )
131             allocate( covar(1:num_bins2d) )
132             allocate( var(1:num_bins2d) )
133             bin_pts2d(:) = 0
134             covar(:) = 0.0
135             var(:) = 0.0
136             first_time = .false.
137          end if
138 
139 !        Read 2D first field:
140          filename = trim(variable1)//'/'//date(1:10)
141          filename = trim(filename)//'.'//trim(variable1)//'.e'//ce//'.01'
142          open (iunit, file = filename, form='unformatted')
143          read(iunit)ni, nj, nkdum
144          read(iunit)field1
145          close(iunit)
146 
147 !        Read 2D second field:
148          filename = trim(variable2)//'/'//date(1:10)
149          filename = trim(filename)//'.'//trim(variable2)//'.e'//ce//'.01'
150          open (iunit, file = filename, form='unformatted')
151          read(iunit)ni, nj, nkdum
152          read(iunit)field2
153          close(iunit)
154 
155 !        Calculate covariances:
156 
157          do j = 1, nj
158             do i = 1, ni
159                b = bin2d(i,j)
160                bin_pts2d(b) = bin_pts2d(b) + 1
161                coeffa = 1.0 / real(bin_pts2d(b))
162                coeffb = real(bin_pts2d(b)-1) * coeffa
163                covar(b) = coeffb * covar(b) + coeffa * field1(i,j) * field2(i,j)
164                var(b) = coeffb * var(b) + coeffa * field2(i,j) * field2(i,j)
165             end do
166          end do
167       end do  ! End loop over ensemble members.
168 
169 !     Calculate next date:
170       call da_advance_cymdh( date, interval, new_date )
171       date = new_date
172       read(date(1:10), fmt='(i10)')cdate
173    end do     ! End loop over times.
174 
175    filename = trim(variable1)//'.'//trim(variable2)//'.dat'
176    open (ounit, file = filename, status='unknown')
177    
178    do j = 1, nj
179       do i = 1, ni
180          b = bin2d(i,j)
181          write(ounit,'(f16.8)')covar(b) / var(b)
182       end do
183    end do
184 
185 end program gen_be_cov2d