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| The metadata for the collection <code>inst01hr_3d_T_Cv</code> is available at | | The metadata for the collection <code>inst01hr_3d_T_Cv</code> is available at |
| http://opendap.nccs.nasa.gov/dods/OSSE/G5NR/Ganymed/7km/0.5000_deg/inst/inst01hr_3d_T_Cv.info | | http://opendap.nccs.nasa.gov/dods/OSSE/G5NR/Ganymed/7km/0.5000_deg/inst/inst01hr_3d_T_Cv.info |
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| == Read downloaded nc4 file ==
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| We first download the collection inst01hr_3d_T_Cv for 2006-Sep-18/0900z as described [[G5NR Data Access Guide#ftp (global data)|here]]. The downloaded file is <code>c1440_NR.inst01hr_3d_T_Cv.20060918_0900z.nc4</code>. The code below does the following
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| * reads global temperature data and computes its max/min
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| * reads a subset of the data and computes the subset's max/min
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| ==== Code ==== | | ==== Code ==== |
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| <syntaxhighlight lang="fortran" line> | | <syntaxhighlight lang="fortran" line> |
| program g5nr_reader
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|
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| use netcdf ! for reading the NR files
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|
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| implicit none
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|
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| ! File name
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| ! ---------
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| character(len=256) :: T_file
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|
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| ! 4D array: (lon,lat,lev,time)
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| ! ------------------------------------
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| real, allocatable :: T(:,:,:,:) ! global data
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| real, allocatable :: Tsub(:,:,:,:) ! subset of global data
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|
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| ! Miscellaneous
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| ! -------------
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| integer :: ierr
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| integer :: im, jm, lm
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| real :: minlat, minlon, maxlat, maxlon
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| integer :: im_sub, jm_sub
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| integer :: imin, imax, jmin, jmax
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| integer :: ncid, varid
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| integer :: start(4), count(4)
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|
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| ! file name and dimensions
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| ! ------------------------
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| im = 720
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| jm = 361
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| lm = 72
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| T_file = "c1440_NR.inst01hr_3d_T_Cv.20060918_0900z.nc4"
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|
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| ! Open file and get var id
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| ! ------------------------
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| call check(nf90_open(T_file,NF90_NOWRITE,ncid), "opening T file")
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| call check(nf90_inq_varid(ncid,"T",varid), "getting T varid")
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|
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| ! Read global temperature data
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| ! ----------------------------
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| allocate(T(im,jm,lm,1)) ! global 4D array with 1 time level
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| start = [1, 1, 1, 1]
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| count = [im, jm, lm, 1] ! 1 time level, 3D (lon,lat,lev) array
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| write(*,*) 'Reading global T...'
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| call check(nf90_get_var(ncid,varid,T,start=start,count=count), "reading T")
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| write(*,*)'T: ', maxval(T),minval(T)
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|
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| ! Read temperature over US
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| ! lons = -180:0.5:179.5
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| ! lats = -90:0.5:90
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| ! ------------------------
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| write(*,*) 'Reading T over US'
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| minlon = -130.
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| maxlon = -65.
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| minlat = 25.
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| maxlat = 50.
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| imin = nint((minlon + 180.)/0.5)
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| imax = nint((maxlon + 180.)/0.5)
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| jmin = nint((minlat + 90.)/0.5)
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| jmax = nint((maxlat + 90.)/0.5)
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| im_sub = imax-imin+1
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| jm_sub = jmax-jmin+1
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| allocate(Tsub(im_sub,jm_sub,lm,1)) ! global 4D array with 1 time level
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| start = [1, 1, 1, 1]
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| count = [im_sub, jm_sub, lm, 1] ! 1 time level, 3D (lon,lat,lev) array
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| call check(nf90_get_var(ncid,varid,Tsub,start=start,count=count), "reading Tsub")
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| write(*,*)'Tsub: ', maxval(Tsub),minval(Tsub)
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|
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| ! close file, release memory
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| call check(nf90_close(ncid), "closing T file")
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| deallocate(T)
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| deallocate(Tsub)
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|
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| ! All done
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| ! --------
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|
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| contains
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| subroutine check(status, loc)
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|
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| integer, intent(in) :: status
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| character(len=*), intent(in) :: loc
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| if(status /= NF90_NOERR) then
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| write (*,*) "Error at ", loc
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| write (*,*) NF90_STRERROR(status)
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| end if
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| end subroutine check
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| end program g5nr_reader
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| </syntaxhighlight> | | </syntaxhighlight> |
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