NCEPLIBS-ip/ip__grid__descriptor__mod_8F90_source.html

module ip_grid_descriptor_mod

  implicit none


  private


  public :: ip_grid_descriptor

  public :: grib1_descriptor, grib2_descriptor

  public :: init_descriptor, init_grib1_descriptor, init_grib2_descriptor


  public :: operator(==)


  type, abstract :: ip_grid_descriptor

     integer :: grid_num

   contains

     procedure :: is_same_grid

  end type ip_grid_descriptor


  type, extends(ip_grid_descriptor) :: grib1_descriptor

     integer :: gds(200)

   contains

     procedure :: is_same_grid_grib1

  end type grib1_descriptor


  type, extends(ip_grid_descriptor) :: grib2_descriptor

     integer :: gdt_num

     integer :: gdt_len

     integer, allocatable :: gdt_tmpl(:)

   contains

     procedure :: is_same_grid_grib2

  end type grib2_descriptor


  interface operator (==)

     module procedure is_same_grid


  end interface operator (==)


  interface init_descriptor

     module procedure init_grib1_descriptor

     module procedure init_grib2_descriptor


  end interface init_descriptor


contains


  function init_grib1_descriptor(gds) result(desc)

    type(grib1_descriptor) :: desc

    integer, intent(in) :: gds(:)

    desc%gds = gds

    desc%grid_num = gds(1)


    !call desc%decode_template()


  end function init_grib1_descriptor


  function init_grib2_descriptor(gdt_num, gdt_len, gdt_tmpl) result(desc)

    type(grib2_descriptor) :: desc

    integer, intent(in) :: gdt_num, gdt_len, gdt_tmpl(:)

    desc%grid_num = gdt_num


    desc%gdt_num = gdt_num

    desc%gdt_len = gdt_len

    allocate(desc%gdt_tmpl(gdt_len))

    desc%gdt_tmpl = gdt_tmpl


    !call desc%decode_template()


  end function init_grib2_descriptor


  logical function is_same_grid(grid1, grid2)

    class(ip_grid_descriptor), intent(in) :: grid1, grid2


    select type(grid1)

    type is(grib1_descriptor)

       select type(grid2)

       type is(grib1_descriptor)

          is_same_grid = grid1%is_same_grid_grib1(grid2)

          class default

          is_same_grid = .false.

       end select

    type is(grib2_descriptor)

       select type(grid2)

       type is(grib2_descriptor)

          is_same_grid = grid1%is_same_grid_grib2(grid2)

          class default

          is_same_grid = .false.

       end select

    end select


  end function is_same_grid


  logical function is_same_grid_grib1(self, grid_desc) result(same_grid)

    class(grib1_descriptor), intent(in) :: self, grid_desc


    if (all(self%gds == grid_desc%gds)) then

       same_grid = .true.

    else

       same_grid = .false.

    end if


  end function is_same_grid_grib1


  logical function is_same_grid_grib2(self, grid_desc) result(same_grid)

    class(grib2_descriptor), intent(in) :: self, grid_desc


    same_grid = .false.

    if (self%grid_num == grid_desc%grid_num) then

       if (self%gdt_len == grid_desc%gdt_len) then

          if (all(self%gdt_tmpl == grid_desc%gdt_tmpl)) then

             same_grid = .true.

          end if

       end if

    end if


  end function is_same_grid_grib2


  ! subroutine decode_template_grib1(self)

  !   type(grib1_descriptor), intent(inout) :: self


  !   integer                            :: im, jm, iwrap, jg

  !   integer                            :: iscan, kscan, nscan, nscan_field_pos

  !   integer                            :: jwrap1, jwrap2


  !   real                               :: dlat, dlon

  !   real                               :: rlat1, rlat2

  !   real                               :: rlon1, rlon2


  !   ! set a default value for this to check if it has changed

  !   ! for rotated grids nscan is set = 3, but in other places it's not, so use this special value

  !   ! just for field_position routine

  !   nscan_field_pos = -1


  !   im = self%gds(2)

  !   jm = self%gds(3)

  !   iwrap = 0

  !   jwrap1 = 0

  !   jwrap2 = 0

  !   nscan = mod(self%gds(11) / 32, 2)

  !   kscan = 0


  !   select case(self%gds(1))

  !   case(0)

  !      rlon1=self%gds(5)*1.e-3

  !      rlon2=self%gds(8)*1.e-3

  !      iscan=mod(self%gds(11)/128,2)

  !      if(iscan.eq.0) then

  !         dlon=(mod(rlon2-rlon1-1+3600,360.)+1)/(im-1)

  !      else

  !         dlon=-(mod(rlon1-rlon2-1+3600,360.)+1)/(im-1)

  !      endif

  !      iwrap=nint(360/abs(dlon))

  !      if(im.lt.iwrap) iwrap=0

  !      if(iwrap.gt.0.and.mod(iwrap,2).eq.0) then

  !         rlat1=self%gds(4)*1.e-3

  !         rlat2=self%gds(7)*1.e-3

  !         dlat=abs(rlat2-rlat1)/(jm-1)

  !         if(abs(rlat1).gt.90-0.25*dlat) then

  !            jwrap1=2

  !         elseif(abs(rlat1).gt.90-0.75*dlat) then

  !            jwrap1=1

  !         endif

  !         if(abs(rlat2).gt.90-0.25*dlat) then

  !            jwrap2=2*jm

  !         elseif(abs(rlat2).gt.90-0.75*dlat) then

  !            jwrap2=2*jm+1

  !         endif

  !      endif

  !   case(1)

  !      rlon1=self%gds(5)*1.e-3

  !      rlon2=self%gds(8)*1.e-3

  !      iscan=mod(self%gds(11)/128,2)

  !      if(iscan.eq.0) then

  !         dlon=(mod(rlon2-rlon1-1+3600,360.)+1)/(im-1)

  !      else

  !         dlon=-(mod(rlon1-rlon2-1+3600,360.)+1)/(im-1)

  !      endif

  !      iwrap=nint(360/abs(dlon))

  !      if(im.lt.iwrap) iwrap=0

  !   case(4)

  !      rlon1=self%gds(5)*1.e-3

  !      rlon2=self%gds(8)*1.e-3

  !      iscan=mod(self%gds(11)/128,2)

  !      if(iscan.eq.0) then

  !         dlon=(mod(rlon2-rlon1-1+3600,360.)+1)/(im-1)

  !      else

  !         dlon=-(mod(rlon1-rlon2-1+3600,360.)+1)/(im-1)

  !      endif

  !      iwrap=nint(360/abs(dlon))

  !      if(im.lt.iwrap) iwrap=0

  !      if(iwrap.gt.0.and.mod(iwrap,2).eq.0) then

  !         jg=self%gds(10)*2

  !         if(jm.eq.jg) then

  !            jwrap1=1

  !            jwrap2=2*jm+1

  !         endif

  !      endif

  !   case(203)

  !      ! why is nscan set to 3 for this grid?

  !      nscan_field_pos = 3

  !      kscan=mod(self%gds(11) / 256, 2)

  !   case default

  !      print *, "grib1 grid type ", self%gds(1), " not recognized"

  !      error stop

  !   end select


  !   self%im = im

  !   self%jm = jm

  !   self%nm = im * jm

  !   self%iwrap = iwrap

  !   self%jwrap1 = jwrap1

  !   self%jwrap2 = jwrap2

  !   self%nscan = nscan


  !   if (nscan_field_pos == -1) then

  !      ! just use regular value of nscan

  !      self%nscan_field_pos = nscan

  !   else

  !      ! nscan = 3 for rotated grids and is set to 3 for use in field_position

  !      self%nscan_field_pos = nscan_field_pos

  !   end if


  !   self%kscan = kscan


  ! end subroutine decode_template_grib1


  ! subroutine decode_template_grib2(self)

  !   type(grib2_descriptor), intent(inout) :: self


  !   integer                            :: im, jm, iwrap, jg

  !   integer                            :: i_offset_odd, i_offset_even

  !   integer                            :: iscan, kscan, nscan, nscan_field_pos

  !   integer                            :: jwrap1, jwrap2, iscale


  !   real                               :: dlat, dlon

  !   real                               :: rlat1, rlat2

  !   real                               :: rlon1, rlon2


  !   nscan_field_pos = -1


  !   select case(self%gdt_num)

  !   ! EQUIDISTANT CYLINDRICAL

  !   case(0)

  !      im=self%gdt_tmpl(8)

  !      jm=self%gdt_tmpl(9)

  !      nscan=mod(self%gdt_tmpl(19)/32,2)

  !      kscan=0

  !      iscale=self%gdt_tmpl(10)*self%gdt_tmpl(11)

  !      if(iscale==0) iscale=10**6

  !      rlon1=float(self%gdt_tmpl(13))/float(iscale)

  !      rlon2=float(self%gdt_tmpl(16))/float(iscale)

  !      iscan=mod(self%gdt_tmpl(19)/128,2)

  !      if(iscan.eq.0) then

  !         dlon=(mod(rlon2-rlon1-1+3600,360.)+1)/(im-1)

  !      else

  !         dlon=-(mod(rlon1-rlon2-1+3600,360.)+1)/(im-1)

  !      endif

  !      iwrap=nint(360/abs(dlon))

  !      if(im.lt.iwrap) iwrap=0

  !      jwrap1=0

  !      jwrap2=0

  !      if(iwrap.gt.0.and.mod(iwrap,2).eq.0) then

  !         rlat1=float(self%gdt_tmpl(12))/float(iscale)

  !         rlat2=float(self%gdt_tmpl(15))/float(iscale)

  !         dlat=abs(rlat2-rlat1)/(jm-1)

  !         if(abs(rlat1).gt.90-0.25*dlat) then

  !            jwrap1=2

  !         elseif(abs(rlat1).gt.90-0.75*dlat) then

  !            jwrap1=1

  !         endif

  !         if(abs(rlat2).gt.90-0.25*dlat) then

  !            jwrap2=2*jm

  !         elseif(abs(rlat2).gt.90-0.75*dlat) then

  !            jwrap2=2*jm+1

  !         endif

  !      endif

  !   case(1)

  !      i_offset_odd=mod(self%gdt_tmpl(19)/8,2)

  !      i_offset_even=mod(self%gdt_tmpl(19)/4,2)

  !      im=self%gdt_tmpl(8)

  !      jm=self%gdt_tmpl(9)

  !      iwrap=0

  !      jwrap1=0

  !      jwrap2=0

  !      kscan=0

  !      nscan=mod(self%gdt_tmpl(19)/32,2)

  !      if(i_offset_odd/=i_offset_even)then

  !         kscan=i_offset_odd

  !         nscan_field_pos=3

  !      endif

  !   ! MERCATOR CYLINDRICAL

  !   case(10)

  !      im=self%gdt_tmpl(8)

  !      jm=self%gdt_tmpl(9)

  !      rlon1=float(self%gdt_tmpl(11))*1.0e-6

  !      rlon2=float(self%gdt_tmpl(15))*1.0e-6

  !      iscan=mod(self%gdt_tmpl(16)/128,2)

  !      if(iscan.eq.0) then

  !         dlon=(mod(rlon2-rlon1-1+3600,360.)+1)/(im-1)

  !      else

  !         dlon=-(mod(rlon1-rlon2-1+3600,360.)+1)/(im-1)

  !      endif

  !      iwrap=nint(360/abs(dlon))

  !      if(im.lt.iwrap) iwrap=0

  !      jwrap1=0

  !      jwrap2=0

  !      kscan=0

  !      nscan=mod(self%gdt_tmpl(16)/32,2)

  !   ! POLAR STEREOGRAPHIC AZIMUTHAL

  !   case(20)

  !      im=self%gdt_tmpl(8)

  !      jm=self%gdt_tmpl(9)

  !      nscan=mod(self%gdt_tmpl(18)/32,2)

  !      iwrap=0

  !      jwrap1=0

  !      jwrap2=0

  !      kscan=0

  !   ! LAMBERT CONFORMAL CONICAL

  !   case(30)

  !      im=self%gdt_tmpl(8)

  !      jm=self%gdt_tmpl(9)

  !      nscan=mod(self%gdt_tmpl(18)/32,2)

  !      iwrap=0

  !      jwrap1=0

  !      jwrap2=0

  !      kscan=0

  !   ! GAUSSIAN CYLINDRICAL

  !   case(40)

  !      im=self%gdt_tmpl(8)

  !      jm=self%gdt_tmpl(9)

  !      iscale=self%gdt_tmpl(10)*self%gdt_tmpl(11)

  !      if(iscale==0) iscale=10**6

  !      rlon1=float(self%gdt_tmpl(13))/float(iscale)

  !      rlon2=float(self%gdt_tmpl(16))/float(iscale)

  !      iscan=mod(self%gdt_tmpl(19)/128,2)

  !      if(iscan.eq.0) then

  !         dlon=(mod(rlon2-rlon1-1+3600,360.)+1)/(im-1)

  !      else

  !         dlon=-(mod(rlon1-rlon2-1+3600,360.)+1)/(im-1)

  !      endif

  !      iwrap=nint(360/abs(dlon))

  !      if(im.lt.iwrap) iwrap=0

  !      jwrap1=0

  !      jwrap2=0

  !      if(iwrap.gt.0.and.mod(iwrap,2).eq.0) then

  !         jg=self%gdt_tmpl(18)*2

  !         if(jm.eq.jg) then

  !            jwrap1=1

  !            jwrap2=2*jm+1

  !         endif

  !      endif

  !      nscan=mod(self%gdt_tmpl(19)/32,2)

  !      kscan=0

  !   case default

  !      print *, "gdt_num ", self%gdt_num, " not recognized"

  !      error stop

  !   end select


  !   self%im = im

  !   self%jm = jm

  !   self%nm = im*jm

  !   self%iwrap = iwrap

  !   self%jwrap1 = jwrap1

  !   self%jwrap2 = jwrap2

  !   self%nscan = nscan

  !   if (nscan_field_pos == -1) then

  !      self%nscan_field_pos = nscan

  !   else

  !      self%nscan_field_pos = nscan_field_pos

  !   end if

  !   self%kscan = kscan


  ! end subroutine decode_template_grib2


  ! subroutine earth_radius(self, radius, eccen_squared)

  !   class(ip_grid_descriptor), intent(in) :: self

  !   real, intent(out) :: radius, eccen_squared


  !   real :: flat, major_axis, minor_axis

  !   logical :: elliptical


  !   select type(self)

  !   type is(grib1_descriptor)

  !      associate(gds => self%gds)

  !        select case(gds(1))

  !        case(0)

  !           radius = 6.3712d6

  !           eccen_squared = 0d0

  !        case(1)

  !           radius = 6.3712d6

  !           eccen_squared = 0d0

  !        case(3)

  !           radius = 6.3712d6

  !           eccen_squared = 0d0

  !        case(4)

  !           radius = 6.3712d6

  !           eccen_squared = 0d0

  !        case(5)

  !           elliptical = mod(gds(6) / 64, 2) == 1

  !           if (.not. elliptical) then

  !              radius = 6.3712d6

  !              eccen_squared = 0d0

  !           else

  !              radius = 6.378137E6 ! WGS-84

  !              eccen_squared = 0.00669437999013d0

  !           end if

  !        case(203)

  !           radius = 6.3712d6

  !           eccen_squared = 0d0

  !        case(205)

  !           radius = 6.3712d6

  !           eccen_squared = 0d0

  !        case default

  !           print *, "grib1 grid not recognized. gds(1) = ", gds(1)

  !           error stop

  !        end select

  !      end associate

  !   type is(grib2_descriptor)

  !      associate(gdt_tmpl => self%gdt_tmpl)

  !        select case (gdt_tmpl(1))

  !        case (0)

  !           radius = 6367470.0

  !           eccen_squared = 0.0

  !        case (1)  ! user specified spherical

  !           radius = float(gdt_tmpl(3))/float(10**gdt_tmpl(2))

  !           eccen_squared = 0.0

  !        case (2)  ! iau 1965

  !           radius = 6378160.0      ! semi major axis

  !           flat = 1.0/297.0      ! flattening

  !           eccen_squared = (2.0*flat) - (flat**2)

  !        case (3)  ! user specified elliptical (km)

  !           major_axis = float(gdt_tmpl(5))/float(10**gdt_tmpl(4))

  !           major_axis = major_axis * 1000.0

  !           minor_axis = float(gdt_tmpl(7))/float(10**gdt_tmpl(6))

  !           minor_axis = minor_axis * 1000.0

  !           eccen_squared = 1.0 - (minor_axis**2 / major_axis**2)

  !           radius = major_axis

  !        case (4)  ! iag-grs80 model

  !           radius = 6378137.0      ! semi major axis

  !           flat = 1.0/298.2572   ! flattening

  !           eccen_squared = (2.0*flat) - (flat**2)

  !        case (5)  ! wgs84 datum

  !           radius = 6378137.0      ! semi major axis

  !           eccen_squared = 0.00669437999013

  !        case (6)

  !           radius = 6371229.0

  !           eccen_squared = 0.0

  !        case (7)  ! user specified elliptical (m)

  !           major_axis = float(gdt_tmpl(5))/float(10**gdt_tmpl(4))

  !           minor_axis = float(gdt_tmpl(7))/float(10**gdt_tmpl(6))

  !           eccen_squared = 1.0 - (minor_axis**2 / major_axis**2)

  !           radius = major_axis

  !        case (8)

  !           radius = 6371200.0

  !           eccen_squared = 0.0

  !        case default

  !           radius = -9999.

  !           eccen_squared = -9999.

  !           error stop

  !        end select

  !      end associate

  !   class default

  !      print *, "unknown descriptor type"

  !      error stop

  !   end select

  ! end subroutine earth_radius


end module ip_grid_descriptor_mod

ip_grid_descriptor_mod::init_descriptor
Definition ip_grid_descriptor_mod.F90:63

ip_grid_descriptor_mod
Users derived type grid descriptor objects to abstract away the raw GRIB1 and GRIB2 grid definitions.
Definition ip_grid_descriptor_mod.F90:15

ip_grid_descriptor_mod::init_grib2_descriptor
type(grib2_descriptor) function, public init_grib2_descriptor(gdt_num, gdt_len, gdt_tmpl)
Initialize grib-2 descriptor from integer grid definition template (GDT).
Definition ip_grid_descriptor_mod.F90:97

ip_grid_descriptor_mod::is_same_grid
logical function is_same_grid(grid1, grid2)
Test whether two grid descriptors are the same.
Definition ip_grid_descriptor_mod.F90:119

ip_grid_descriptor_mod::is_same_grid_grib1
logical function is_same_grid_grib1(self, grid_desc)
Test whether two grib1_descriptors are the same.
Definition ip_grid_descriptor_mod.F90:149

ip_grid_descriptor_mod::is_same_grid_grib2
logical function is_same_grid_grib2(self, grid_desc)
Test whether two grib2_descriptors are the same.
Definition ip_grid_descriptor_mod.F90:168

ip_grid_descriptor_mod::init_grib1_descriptor
type(grib1_descriptor) function, public init_grib1_descriptor(gds)
Initialize grib-1 descriptor from integer grid definition section (GDS).
Definition ip_grid_descriptor_mod.F90:78

ip_grid_descriptor_mod::grib1_descriptor
Descriptor representing a grib1 grib descriptor section (GDS) with an integer array.
Definition ip_grid_descriptor_mod.F90:39

ip_grid_descriptor_mod::grib2_descriptor
Grib-2 descriptor containing a grib2 GDT represented by an integer array.
Definition ip_grid_descriptor_mod.F90:49

ip_grid_descriptor_mod::ip_grid_descriptor
Abstract descriptor object which represents a grib1 or grib2 descriptor.
Definition ip_grid_descriptor_mod.F90:28