MOM_hor_index.F90

1! This file is part of MOM6, the Modular Ocean Model version 6.

2! See the LICENSE file for licensing information.

3! SPDX-License-Identifier: Apache-2.0

4

5!> Defines the horizontal index type (hor_index_type) used for providing index ranges

6module mom_hor_index

7

8use mom_domains, only : mom_domain_type, get_domain_extent, get_global_shape

9use mom_error_handler, only : mom_error, mom_mesg, fatal

10use mom_file_parser, only : get_param, log_param, log_version, param_file_type

11

12implicit none ; private

13

14public :: hor_index_init, assignment(=)

15public :: rotate_hor_index

16

17!> Container for horizontal index ranges for data, computational and global domains

18type, public :: hor_index_type

19 integer :: isc !< The start i-index of cell centers within the computational domain

20 integer :: iec !< The end i-index of cell centers within the computational domain

21 integer :: jsc !< The start j-index of cell centers within the computational domain

22 integer :: jec !< The end j-index of cell centers within the computational domain

23

24 integer :: isd !< The start i-index of cell centers within the data domain

25 integer :: ied !< The end i-index of cell centers within the data domain

26 integer :: jsd !< The start j-index of cell centers within the data domain

27 integer :: jed !< The end j-index of cell centers within the data domain

28

29 integer :: isg !< The start i-index of cell centers within the global domain

30 integer :: ieg !< The end i-index of cell centers within the global domain

31 integer :: jsg !< The start j-index of cell centers within the global domain

32 integer :: jeg !< The end j-index of cell centers within the global domain

33

34 integer :: iscb !< The start i-index of cell vertices within the computational domain

35 integer :: iecb !< The end i-index of cell vertices within the computational domain

36 integer :: jscb !< The start j-index of cell vertices within the computational domain

37 integer :: jecb !< The end j-index of cell vertices within the computational domain

38

39 integer :: isdb !< The start i-index of cell vertices within the data domain

40 integer :: iedb !< The end i-index of cell vertices within the data domain

41 integer :: jsdb !< The start j-index of cell vertices within the data domain

42 integer :: jedb !< The end j-index of cell vertices within the data domain

43

44 integer :: isgb !< The start i-index of cell vertices within the global domain

45 integer :: iegb !< The end i-index of cell vertices within the global domain

46 integer :: jsgb !< The start j-index of cell vertices within the global domain

47 integer :: jegb !< The end j-index of cell vertices within the global domain

48

49 integer :: idg_offset !< The offset between the corresponding global and local i-indices.

50 integer :: jdg_offset !< The offset between the corresponding global and local j-indices.

51 logical :: symmetric !< True if symmetric memory is used.

52

53 integer :: niglobal !< The global number of h-cells in the i-direction

54 integer :: njglobal !< The global number of h-cells in the j-direction

55

56 integer :: turns !< Number of quarter-turn rotations from input to model

57end type hor_index_type

58

59!> Copy the contents of one horizontal index type into another

60interface assignment(=) ; module procedure HIT_assign ; end interface

61

62contains

63

64!> Sets various index values in a hor_index_type.

65subroutine hor_index_init(Domain, HI, param_file, local_indexing, index_offset)

66 type(mom_domain_type), intent(in) :: domain !< The MOM domain from which to extract information.

67 type(hor_index_type), intent(inout) :: hi !< A horizontal index type to populate with data

68 type(param_file_type), optional, intent(in) :: param_file !< Parameter file handle

69 logical, optional, intent(in) :: local_indexing !< If true, all tracer data domains start at 1

70 integer, optional, intent(in) :: index_offset !< A fixed additional offset to all indices

71

72! This include declares and sets the variable "version".

73#include "version_variable.h"

74

75 ! get_domain_extent ensures that domains start at 1 for compatibility between

76 ! static and dynamically allocated arrays.

77 call get_domain_extent(domain, hi%isc, hi%iec, hi%jsc, hi%jec, &

78 hi%isd, hi%ied, hi%jsd, hi%jed, &

79 hi%isg, hi%ieg, hi%jsg, hi%jeg, &

80 hi%idg_offset, hi%jdg_offset, hi%symmetric, &

81 local_indexing=local_indexing)

82 call get_global_shape(domain, hi%niglobal, hi%njglobal)

83

84 ! Read all relevant parameters and write them to the model log.

85 if (present(param_file)) &

86 call log_version(param_file, "MOM_hor_index", version, &

87 "Sets the horizontal array index types.", all_default=.true.)

88

89 hi%IscB = hi%isc ; hi%JscB = hi%jsc

90 hi%IsdB = hi%isd ; hi%JsdB = hi%jsd

91 hi%IsgB = hi%isg ; hi%JsgB = hi%jsg

92 if (hi%symmetric) then

93 hi%IscB = hi%isc-1 ; hi%JscB = hi%jsc-1

94 hi%IsdB = hi%isd-1 ; hi%JsdB = hi%jsd-1

95 hi%IsgB = hi%isg-1 ; hi%JsgB = hi%jsg-1

96 endif

97 hi%IecB = hi%iec ; hi%JecB = hi%jec

98 hi%IedB = hi%ied ; hi%JedB = hi%jed

99 hi%IegB = hi%ieg ; hi%JegB = hi%jeg

100

101 hi%turns = 0

102end subroutine hor_index_init

103

104!> HIT_assign copies one hor_index_type into another. It is accessed via an

105!! assignment (=) operator.

106subroutine hit_assign(HI1, HI2)

107 type(hor_index_type), intent(out) :: HI1 !< Horizontal index type to copy to

108 type(hor_index_type), intent(in) :: HI2 !< Horizontal index type to copy from

109 ! This subroutine copies all components of the horizontal array index type

110 ! variable on the RHS (HI2) to the variable on the LHS (HI1).

111

112 hi1%isc = hi2%isc ; hi1%iec = hi2%iec ; hi1%jsc = hi2%jsc ; hi1%jec = hi2%jec

113 hi1%isd = hi2%isd ; hi1%ied = hi2%ied ; hi1%jsd = hi2%jsd ; hi1%jed = hi2%jed

114 hi1%isg = hi2%isg ; hi1%ieg = hi2%ieg ; hi1%jsg = hi2%jsg ; hi1%jeg = hi2%jeg

115

116 hi1%IscB = hi2%IscB ; hi1%IecB = hi2%IecB ; hi1%JscB = hi2%JscB ; hi1%JecB = hi2%JecB

117 hi1%IsdB = hi2%IsdB ; hi1%IedB = hi2%IedB ; hi1%JsdB = hi2%JsdB ; hi1%JedB = hi2%JedB

118 hi1%IsgB = hi2%IsgB ; hi1%IegB = hi2%IegB ; hi1%JsgB = hi2%JsgB ; hi1%JegB = hi2%JegB

119

120 hi1%niglobal = hi2%niglobal ; hi1%njglobal = hi2%njglobal

121 hi1%idg_offset = hi2%idg_offset ; hi1%jdg_offset = hi2%jdg_offset

122 hi1%symmetric = hi2%symmetric

123 hi1%turns = hi2%turns

124end subroutine hit_assign

125

126!> Rotate the horizontal index ranges from the input to the output map.

127subroutine rotate_hor_index(HI_in, turns, HI)

128 type(hor_index_type), intent(in) :: hi_in !< Unrotated horizontal indices

129 integer, intent(in) :: turns !< Number of quarter turns

130 type(hor_index_type), intent(inout) :: hi !< Rotated horizontal indices

131

132 if (modulo(turns, 2) /= 0) then

133 hi%isc = hi_in%jsc

134 hi%iec = hi_in%jec

135 hi%jsc = hi_in%isc

136 hi%jec = hi_in%iec

137 hi%isd = hi_in%jsd

138 hi%ied = hi_in%jed

139 hi%jsd = hi_in%isd

140 hi%jed = hi_in%ied

141 hi%isg = hi_in%jsg

142 hi%ieg = hi_in%jeg

143 hi%jsg = hi_in%isg

144 hi%jeg = hi_in%ieg

145

146 hi%IscB = hi_in%JscB

147 hi%IecB = hi_in%JecB

148 hi%JscB = hi_in%IscB

149 hi%JecB = hi_in%IecB

150 hi%IsdB = hi_in%JsdB

151 hi%IedB = hi_in%JedB

152 hi%JsdB = hi_in%IsdB

153 hi%JedB = hi_in%IedB

154 hi%IsgB = hi_in%JsgB

155 hi%IegB = hi_in%JegB

156 hi%JsgB = hi_in%IsgB

157 hi%JegB = hi_in%IegB

158

159 hi%niglobal = hi_in%njglobal

160 hi%njglobal = hi_in%niglobal

161 hi%idg_offset = hi_in%jdg_offset

162 hi%jdg_offset = hi_in%idg_offset

163

164 hi%symmetric = hi_in%symmetric

165 else

166 hi = hi_in

167 endif

168 hi%turns = hi_in%turns + turns

169end subroutine rotate_hor_index

170

171!> \namespace mom_hor_index

172!!

173!! The hor_index_type provides the declarations and loop ranges for almost all data with horizontal extent.

174!!

175!! Declarations and loop ranges should always be coded with the symmetric memory model in mind.

176!! The non-symmetric memory mode will then also work, albeit with a different (less efficient) communication pattern.

177!!

178!! Using the hor_index_type HI:

179!! - declaration of h-point data is of the form `h(HI%%isd:HI%%ied,HI%%jsd:HI%%jed)`

180!! - declaration of q-point data is of the form `q(HI%%IsdB:HI%%IedB,HI%%JsdB:HI%%JedB)`

181!! - declaration of u-point data is of the form `u(HI%%IsdB:HI%%IedB,HI%%jsd:HI%%jed)`

182!! - declaration of v-point data is of the form `v(HI%%isd:HI%%ied,HI%%JsdB:HI%%JedB)`.

183!!

184!! For more detail explanation of horizontal indexing see \ref Horizontal_Indexing.

185

186

187end module mom_hor_index