program readavg

!--------------------------------------
! Program usage eg.
!  f90 readavg.f90 -o readavg
!  readavg surfrad_DRA_199901_avg.v3.0
!--------------------------------------

  Implicit none

  TYPE Hdr_Type_SAM
    Sequence
    Character (Len=64) :: Site_ID 		    !   64 bytes    64 
    Character (Len=4)  :: year			    !    4 bytes    68
    Character (Len=4)  :: mon			    !    4 bytes    72
    Real    :: lat				    !    4 bytes    76
    Real    :: lon				    !    4 bytes    80
    Real    :: elev				    !    4 bytes    84
    Real    :: extras				    !    4 bytes    88
    Character (Len=32), Dimension(50) :: label      ! 1600 bytes  1688
    Character (Len=10216) :: padding		    !10216 bytes 11904
  END TYPE Hdr_Type_SAM

  TYPE (Hdr_Type_SAM) hdr

  real, dimension(2976,50) :: dat

  character (len=80) :: filename
  integer :: iv,ie,next,i,ibg,ien

  Call getarg(1,filename)

  Call ReadFile(filename,hdr,dat)

  Call PrintHdr(hdr)

!---
! Set "iv" to the desired field (1 to 22)
! Set "ie" to the desired extra field if available (1 to next)
!---
  next = hdr%extras
  print*,'Input desired variable'
  read(5,"(i3)")iv
  write(6,"('Average for - ',a32)")hdr%label(iv)
  Do i=1,31
    ibg = (i-1)*96+1
    ien = ibg+95
    write(6,"(10f8.2)")dat(ibg:ien,iv) ! dat(1:148,iv)
  Enddo

  close(1)

End Program readavg

Subroutine ReadFile(filename,hdr,dat)

  TYPE Hdr_Type_SAM
    Sequence
    Character (Len=64) :: Site_ID 		    !   64 bytes    64 
    Character (Len=4)  :: year			    !    4 bytes    68
    Character (Len=4)  :: mon			    !    4 bytes    72
    Real    :: lat				    !    4 bytes    76
    Real    :: lon				    !    4 bytes    80
    Real    :: elev				    !    4 bytes    84
    Real    :: extras				    !    4 bytes    88
    Character (Len=32), Dimension(50) :: label      ! 1600 bytes  1688
    Character (Len=10216) :: padding		    !10216 bytes 11904
  END TYPE Hdr_Type_SAM

  TYPE (Hdr_Type_SAM) hdr

  real, dimension(2976,50) :: dat
  integer :: i,irec,next,ntot
  character (len=80) :: filename

  irec=1
  open(1,file=filename,form='unformatted',access='direct',recl=11904,status='old')
  read(1,rec=irec)hdr
  next = int(hdr%extras)
  ntot = 22+next
  Do i=1,ntot
    irec=irec+1
    read(1,rec=irec)dat(:,i)
  Enddo

  Close(1)

End Subroutine ReadFile
  
Subroutine PrintHdr(hdr)

  TYPE Hdr_Type_SAM
    Sequence
    Character (Len=64) :: Site_ID 		    !   64 bytes    64 
    Character (Len=4)  :: year			    !    4 bytes    68
    Character (Len=4)  :: mon			    !    4 bytes    72
    Real    :: lat				    !    4 bytes    76
    Real    :: lon				    !    4 bytes    80
    Real    :: elev				    !    4 bytes    84
    Real    :: extras				    !    4 bytes    88
    Character (Len=32), Dimension(50) :: label      ! 1600 bytes  1688
    Character (Len=10216) :: padding		    !10216 bytes 11904
  END TYPE Hdr_Type_SAM

  TYPE (Hdr_Type_SAM) hdr

  integer :: i

  write(6,*)
  write(6,*)'---------------------------------------------------'
  write(6,"(/'Station Name - ',a64)")hdr%Site_ID
  write(6,"('Date - ',2a4)")hdr%mon,hdr%year
  write(6,"('Lat - ',f8.2/,'Lon - ',f8.2)")hdr%lat,hdr%lon
  write(6,"('Elevation - ',f8.2,' m'/,'Extra Variables - ',f3.0/)")hdr%elev,hdr%extras
  write(6,"(4x,'Index',8x,'Field',12x,'Units',1x,'Availability')")
  write(6,"(4x,'-----',8x,'-----',12x,'-----',1x,'------------')")

  do i=1,22
    write(6,"('Variable ',i2,' - ',a32)")i,hdr%label(i)
  enddo
  next = int(hdr%extras)
  ntot = 22+next
  if(next > 0)then 
    write(6,"(a41)")'Plus these extra variables for this site:'
    do i=23,ntot
      write(6,"('Variable ',i2,' - ',a32)")i,hdr%label(i)
    enddo
  endif
  write(6,*)


End Subroutine PrintHdr

!--------Base Variable Locations in Array----------!
!(for extra variables, read the header information)!
!--------------------------------------------------!
!	( 1) = 'Cos(Sol Zen Ang)'
!	( 2) = 'LW Flux DN	'
!	( 3) = 'LW Flux UP	'
!	( 4) = 'SW Global DN	'
!	( 5) = 'SW Global UP	'
!	( 6) = 'SW Direct Normal'
!	( 7) = 'SW Dif DN       '
!	( 8) = 'Total SW, 15MinAvg'
!	( 9) = 'Temp Surface Air'
!	(10) = 'Sfc Pressure	'
!	(11) = 'Sfc Wind Speed  '
!	(12) = 'Sfc Wind Dir	'
!	(13) = 'Sfc Rel Humidity'
!       (14) = 'Cld Frct Pyrn based'
!	(15) = 'Aer OD-1 nnnn nm'
!	(16) = 'Aer OD-2 nnnn nm'
!	(17) = 'Aer OD-3 nnnn nm'
!	(18) = 'Aer OD-4 nnnn nm'
!	(19) = 'Aer OD-5 nnnn nm'
!	(20) = 'Aer OD-6 nnnn nm'
!	(21) = 'Aer OD-7 nnnn nm'
!	(22) = 'Aer PW          '
!--------------------------------------------------!