[1262] | 1 | Module m_mrgrnk |
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[3241] | 2 | IMPLICIT NONE |
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[1262] | 3 | Integer, Parameter :: kdp = selected_real_kind(15) |
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| 4 | public :: mrgrnk |
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| 5 | private :: kdp |
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| 6 | private :: I_mrgrnk, D_mrgrnk |
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| 7 | interface mrgrnk |
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| 8 | module procedure D_mrgrnk, I_mrgrnk |
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| 9 | end interface mrgrnk |
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| 10 | contains |
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| 11 | |
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| 12 | Subroutine D_mrgrnk (XDONT, IRNGT) |
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| 13 | ! __________________________________________________________ |
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| 14 | ! MRGRNK = Merge-sort ranking of an array |
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| 15 | ! For performance reasons, the first 2 passes are taken |
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| 16 | ! out of the standard loop, and use dedicated coding. |
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| 17 | ! __________________________________________________________ |
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| 18 | ! __________________________________________________________ |
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| 19 | Real (kind=kdp), Dimension (:), Intent (In) :: XDONT |
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| 20 | Integer, Dimension (:), Intent (Out) :: IRNGT |
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| 21 | ! __________________________________________________________ |
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| 22 | Real (kind=kdp) :: XVALA, XVALB |
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| 23 | ! |
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| 24 | Integer, Dimension (SIZE(IRNGT)) :: JWRKT |
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| 25 | Integer :: LMTNA, LMTNC, IRNG1, IRNG2 |
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| 26 | Integer :: NVAL, IIND, IWRKD, IWRK, IWRKF, JINDA, IINDA, IINDB |
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| 27 | ! |
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| 28 | NVAL = Min (SIZE(XDONT), SIZE(IRNGT)) |
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| 29 | Select Case (NVAL) |
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| 30 | Case (:0) |
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| 31 | Return |
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| 32 | Case (1) |
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| 33 | IRNGT (1) = 1 |
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| 34 | Return |
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| 35 | Case Default |
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| 36 | Continue |
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| 37 | End Select |
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| 38 | ! |
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| 39 | ! Fill-in the index array, creating ordered couples |
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| 40 | ! |
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| 41 | Do IIND = 2, NVAL, 2 |
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| 42 | If (XDONT(IIND-1) <= XDONT(IIND)) Then |
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| 43 | IRNGT (IIND-1) = IIND - 1 |
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| 44 | IRNGT (IIND) = IIND |
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| 45 | Else |
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| 46 | IRNGT (IIND-1) = IIND |
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| 47 | IRNGT (IIND) = IIND - 1 |
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| 48 | End If |
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| 49 | End Do |
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| 50 | If (Modulo(NVAL, 2) /= 0) Then |
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| 51 | IRNGT (NVAL) = NVAL |
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| 52 | End If |
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| 53 | ! |
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| 54 | ! We will now have ordered subsets A - B - A - B - ... |
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| 55 | ! and merge A and B couples into C - C - ... |
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| 56 | ! |
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| 57 | LMTNA = 2 |
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| 58 | LMTNC = 4 |
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| 59 | ! |
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| 60 | ! First iteration. The length of the ordered subsets goes from 2 to 4 |
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| 61 | ! |
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| 62 | Do |
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| 63 | If (NVAL <= 2) Exit |
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| 64 | ! |
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| 65 | ! Loop on merges of A and B into C |
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| 66 | ! |
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| 67 | Do IWRKD = 0, NVAL - 1, 4 |
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| 68 | If ((IWRKD+4) > NVAL) Then |
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| 69 | If ((IWRKD+2) >= NVAL) Exit |
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| 70 | ! |
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| 71 | ! 1 2 3 |
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| 72 | ! |
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| 73 | If (XDONT(IRNGT(IWRKD+2)) <= XDONT(IRNGT(IWRKD+3))) Exit |
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| 74 | ! |
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| 75 | ! 1 3 2 |
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| 76 | ! |
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| 77 | If (XDONT(IRNGT(IWRKD+1)) <= XDONT(IRNGT(IWRKD+3))) Then |
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| 78 | IRNG2 = IRNGT (IWRKD+2) |
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| 79 | IRNGT (IWRKD+2) = IRNGT (IWRKD+3) |
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| 80 | IRNGT (IWRKD+3) = IRNG2 |
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| 81 | ! |
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| 82 | ! 3 1 2 |
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| 83 | ! |
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| 84 | Else |
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| 85 | IRNG1 = IRNGT (IWRKD+1) |
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| 86 | IRNGT (IWRKD+1) = IRNGT (IWRKD+3) |
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| 87 | IRNGT (IWRKD+3) = IRNGT (IWRKD+2) |
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| 88 | IRNGT (IWRKD+2) = IRNG1 |
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| 89 | End If |
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| 90 | Exit |
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| 91 | End If |
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| 92 | ! |
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| 93 | ! 1 2 3 4 |
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| 94 | ! |
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| 95 | If (XDONT(IRNGT(IWRKD+2)) <= XDONT(IRNGT(IWRKD+3))) Cycle |
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| 96 | ! |
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| 97 | ! 1 3 x x |
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| 98 | ! |
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| 99 | If (XDONT(IRNGT(IWRKD+1)) <= XDONT(IRNGT(IWRKD+3))) Then |
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| 100 | IRNG2 = IRNGT (IWRKD+2) |
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| 101 | IRNGT (IWRKD+2) = IRNGT (IWRKD+3) |
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| 102 | If (XDONT(IRNG2) <= XDONT(IRNGT(IWRKD+4))) Then |
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| 103 | ! 1 3 2 4 |
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| 104 | IRNGT (IWRKD+3) = IRNG2 |
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| 105 | Else |
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| 106 | ! 1 3 4 2 |
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| 107 | IRNGT (IWRKD+3) = IRNGT (IWRKD+4) |
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| 108 | IRNGT (IWRKD+4) = IRNG2 |
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| 109 | End If |
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| 110 | ! |
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| 111 | ! 3 x x x |
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| 112 | ! |
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| 113 | Else |
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| 114 | IRNG1 = IRNGT (IWRKD+1) |
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| 115 | IRNG2 = IRNGT (IWRKD+2) |
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| 116 | IRNGT (IWRKD+1) = IRNGT (IWRKD+3) |
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| 117 | If (XDONT(IRNG1) <= XDONT(IRNGT(IWRKD+4))) Then |
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| 118 | IRNGT (IWRKD+2) = IRNG1 |
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| 119 | If (XDONT(IRNG2) <= XDONT(IRNGT(IWRKD+4))) Then |
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| 120 | ! 3 1 2 4 |
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| 121 | IRNGT (IWRKD+3) = IRNG2 |
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| 122 | Else |
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| 123 | ! 3 1 4 2 |
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| 124 | IRNGT (IWRKD+3) = IRNGT (IWRKD+4) |
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| 125 | IRNGT (IWRKD+4) = IRNG2 |
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| 126 | End If |
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| 127 | Else |
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| 128 | ! 3 4 1 2 |
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| 129 | IRNGT (IWRKD+2) = IRNGT (IWRKD+4) |
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| 130 | IRNGT (IWRKD+3) = IRNG1 |
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| 131 | IRNGT (IWRKD+4) = IRNG2 |
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| 132 | End If |
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| 133 | End If |
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| 134 | End Do |
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| 135 | ! |
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| 136 | ! The Cs become As and Bs |
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| 137 | ! |
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| 138 | LMTNA = 4 |
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| 139 | Exit |
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| 140 | End Do |
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| 141 | ! |
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| 142 | ! Iteration loop. Each time, the length of the ordered subsets |
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| 143 | ! is doubled. |
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| 144 | ! |
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| 145 | Do |
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| 146 | If (LMTNA >= NVAL) Exit |
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| 147 | IWRKF = 0 |
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| 148 | LMTNC = 2 * LMTNC |
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| 149 | ! |
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| 150 | ! Loop on merges of A and B into C |
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| 151 | ! |
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| 152 | Do |
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| 153 | IWRK = IWRKF |
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| 154 | IWRKD = IWRKF + 1 |
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| 155 | JINDA = IWRKF + LMTNA |
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| 156 | IWRKF = IWRKF + LMTNC |
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| 157 | If (IWRKF >= NVAL) Then |
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| 158 | If (JINDA >= NVAL) Exit |
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| 159 | IWRKF = NVAL |
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| 160 | End If |
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| 161 | IINDA = 1 |
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| 162 | IINDB = JINDA + 1 |
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| 163 | ! |
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| 164 | ! Shortcut for the case when the max of A is smaller |
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| 165 | ! than the min of B. This line may be activated when the |
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| 166 | ! initial set is already close to sorted. |
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| 167 | ! |
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| 168 | ! IF (XDONT(IRNGT(JINDA)) <= XDONT(IRNGT(IINDB))) CYCLE |
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| 169 | ! |
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| 170 | ! One steps in the C subset, that we build in the final rank array |
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| 171 | ! |
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| 172 | ! Make a copy of the rank array for the merge iteration |
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| 173 | ! |
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| 174 | JWRKT (1:LMTNA) = IRNGT (IWRKD:JINDA) |
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| 175 | ! |
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| 176 | XVALA = XDONT (JWRKT(IINDA)) |
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| 177 | XVALB = XDONT (IRNGT(IINDB)) |
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| 178 | ! |
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| 179 | Do |
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| 180 | IWRK = IWRK + 1 |
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| 181 | ! |
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| 182 | ! We still have unprocessed values in both A and B |
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| 183 | ! |
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| 184 | If (XVALA > XVALB) Then |
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| 185 | IRNGT (IWRK) = IRNGT (IINDB) |
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| 186 | IINDB = IINDB + 1 |
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| 187 | If (IINDB > IWRKF) Then |
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| 188 | ! Only A still with unprocessed values |
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| 189 | IRNGT (IWRK+1:IWRKF) = JWRKT (IINDA:LMTNA) |
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| 190 | Exit |
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| 191 | End If |
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| 192 | XVALB = XDONT (IRNGT(IINDB)) |
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| 193 | Else |
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| 194 | IRNGT (IWRK) = JWRKT (IINDA) |
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| 195 | IINDA = IINDA + 1 |
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| 196 | If (IINDA > LMTNA) Exit! Only B still with unprocessed values |
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| 197 | XVALA = XDONT (JWRKT(IINDA)) |
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| 198 | End If |
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| 199 | ! |
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| 200 | End Do |
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| 201 | End Do |
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| 202 | ! |
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| 203 | ! The Cs become As and Bs |
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| 204 | ! |
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| 205 | LMTNA = 2 * LMTNA |
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| 206 | End Do |
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| 207 | ! |
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| 208 | Return |
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| 209 | ! |
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| 210 | End Subroutine D_mrgrnk |
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| 211 | |
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| 212 | Subroutine I_mrgrnk (XDONT, IRNGT) |
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| 213 | ! __________________________________________________________ |
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| 214 | ! MRGRNK = Merge-sort ranking of an array |
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| 215 | ! For performance reasons, the first 2 passes are taken |
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| 216 | ! out of the standard loop, and use dedicated coding. |
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| 217 | ! __________________________________________________________ |
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| 218 | ! __________________________________________________________ |
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| 219 | Integer, Dimension (:), Intent (In) :: XDONT |
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| 220 | Integer, Dimension (:), Intent (Out) :: IRNGT |
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| 221 | ! __________________________________________________________ |
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| 222 | Integer :: XVALA, XVALB |
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| 223 | ! |
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| 224 | Integer, Dimension (SIZE(IRNGT)) :: JWRKT |
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| 225 | Integer :: LMTNA, LMTNC, IRNG1, IRNG2 |
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| 226 | Integer :: NVAL, IIND, IWRKD, IWRK, IWRKF, JINDA, IINDA, IINDB |
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| 227 | ! |
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| 228 | NVAL = Min (SIZE(XDONT), SIZE(IRNGT)) |
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| 229 | Select Case (NVAL) |
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| 230 | Case (:0) |
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| 231 | Return |
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| 232 | Case (1) |
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| 233 | IRNGT (1) = 1 |
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| 234 | Return |
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| 235 | Case Default |
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| 236 | Continue |
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| 237 | End Select |
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| 238 | ! |
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| 239 | ! Fill-in the index array, creating ordered couples |
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| 240 | ! |
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| 241 | Do IIND = 2, NVAL, 2 |
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| 242 | If (XDONT(IIND-1) <= XDONT(IIND)) Then |
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| 243 | IRNGT (IIND-1) = IIND - 1 |
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| 244 | IRNGT (IIND) = IIND |
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| 245 | Else |
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| 246 | IRNGT (IIND-1) = IIND |
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| 247 | IRNGT (IIND) = IIND - 1 |
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| 248 | End If |
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| 249 | End Do |
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| 250 | If (Modulo(NVAL, 2) /= 0) Then |
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| 251 | IRNGT (NVAL) = NVAL |
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| 252 | End If |
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| 253 | ! |
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| 254 | ! We will now have ordered subsets A - B - A - B - ... |
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| 255 | ! and merge A and B couples into C - C - ... |
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| 256 | ! |
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| 257 | LMTNA = 2 |
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| 258 | LMTNC = 4 |
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| 259 | ! |
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| 260 | ! First iteration. The length of the ordered subsets goes from 2 to 4 |
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| 261 | ! |
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| 262 | Do |
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| 263 | If (NVAL <= 2) Exit |
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| 264 | ! |
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| 265 | ! Loop on merges of A and B into C |
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| 266 | ! |
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| 267 | Do IWRKD = 0, NVAL - 1, 4 |
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| 268 | If ((IWRKD+4) > NVAL) Then |
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| 269 | If ((IWRKD+2) >= NVAL) Exit |
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| 270 | ! |
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| 271 | ! 1 2 3 |
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| 272 | ! |
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| 273 | If (XDONT(IRNGT(IWRKD+2)) <= XDONT(IRNGT(IWRKD+3))) Exit |
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| 274 | ! |
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| 275 | ! 1 3 2 |
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| 276 | ! |
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| 277 | If (XDONT(IRNGT(IWRKD+1)) <= XDONT(IRNGT(IWRKD+3))) Then |
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| 278 | IRNG2 = IRNGT (IWRKD+2) |
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| 279 | IRNGT (IWRKD+2) = IRNGT (IWRKD+3) |
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| 280 | IRNGT (IWRKD+3) = IRNG2 |
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| 281 | ! |
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| 282 | ! 3 1 2 |
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| 283 | ! |
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| 284 | Else |
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| 285 | IRNG1 = IRNGT (IWRKD+1) |
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| 286 | IRNGT (IWRKD+1) = IRNGT (IWRKD+3) |
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| 287 | IRNGT (IWRKD+3) = IRNGT (IWRKD+2) |
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| 288 | IRNGT (IWRKD+2) = IRNG1 |
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| 289 | End If |
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| 290 | Exit |
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| 291 | End If |
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| 292 | ! |
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| 293 | ! 1 2 3 4 |
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| 294 | ! |
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| 295 | If (XDONT(IRNGT(IWRKD+2)) <= XDONT(IRNGT(IWRKD+3))) Cycle |
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| 296 | ! |
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| 297 | ! 1 3 x x |
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| 298 | ! |
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| 299 | If (XDONT(IRNGT(IWRKD+1)) <= XDONT(IRNGT(IWRKD+3))) Then |
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| 300 | IRNG2 = IRNGT (IWRKD+2) |
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| 301 | IRNGT (IWRKD+2) = IRNGT (IWRKD+3) |
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| 302 | If (XDONT(IRNG2) <= XDONT(IRNGT(IWRKD+4))) Then |
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| 303 | ! 1 3 2 4 |
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| 304 | IRNGT (IWRKD+3) = IRNG2 |
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| 305 | Else |
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| 306 | ! 1 3 4 2 |
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| 307 | IRNGT (IWRKD+3) = IRNGT (IWRKD+4) |
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| 308 | IRNGT (IWRKD+4) = IRNG2 |
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| 309 | End If |
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| 310 | ! |
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| 311 | ! 3 x x x |
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| 312 | ! |
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| 313 | Else |
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| 314 | IRNG1 = IRNGT (IWRKD+1) |
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| 315 | IRNG2 = IRNGT (IWRKD+2) |
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| 316 | IRNGT (IWRKD+1) = IRNGT (IWRKD+3) |
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| 317 | If (XDONT(IRNG1) <= XDONT(IRNGT(IWRKD+4))) Then |
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| 318 | IRNGT (IWRKD+2) = IRNG1 |
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| 319 | If (XDONT(IRNG2) <= XDONT(IRNGT(IWRKD+4))) Then |
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| 320 | ! 3 1 2 4 |
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| 321 | IRNGT (IWRKD+3) = IRNG2 |
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| 322 | Else |
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| 323 | ! 3 1 4 2 |
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| 324 | IRNGT (IWRKD+3) = IRNGT (IWRKD+4) |
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| 325 | IRNGT (IWRKD+4) = IRNG2 |
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| 326 | End If |
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| 327 | Else |
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| 328 | ! 3 4 1 2 |
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| 329 | IRNGT (IWRKD+2) = IRNGT (IWRKD+4) |
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| 330 | IRNGT (IWRKD+3) = IRNG1 |
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| 331 | IRNGT (IWRKD+4) = IRNG2 |
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| 332 | End If |
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| 333 | End If |
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| 334 | End Do |
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| 335 | ! |
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| 336 | ! The Cs become As and Bs |
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| 337 | ! |
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| 338 | LMTNA = 4 |
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| 339 | Exit |
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| 340 | End Do |
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| 341 | ! |
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| 342 | ! Iteration loop. Each time, the length of the ordered subsets |
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| 343 | ! is doubled. |
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| 344 | ! |
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| 345 | Do |
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| 346 | If (LMTNA >= NVAL) Exit |
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| 347 | IWRKF = 0 |
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| 348 | LMTNC = 2 * LMTNC |
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| 349 | ! |
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| 350 | ! Loop on merges of A and B into C |
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| 351 | ! |
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| 352 | Do |
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| 353 | IWRK = IWRKF |
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| 354 | IWRKD = IWRKF + 1 |
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| 355 | JINDA = IWRKF + LMTNA |
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| 356 | IWRKF = IWRKF + LMTNC |
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| 357 | If (IWRKF >= NVAL) Then |
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| 358 | If (JINDA >= NVAL) Exit |
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| 359 | IWRKF = NVAL |
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| 360 | End If |
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| 361 | IINDA = 1 |
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| 362 | IINDB = JINDA + 1 |
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| 363 | ! |
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| 364 | ! Shortcut for the case when the max of A is smaller |
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| 365 | ! than the min of B. This line may be activated when the |
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| 366 | ! initial set is already close to sorted. |
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| 367 | ! |
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| 368 | ! IF (XDONT(IRNGT(JINDA)) <= XDONT(IRNGT(IINDB))) CYCLE |
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| 369 | ! |
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| 370 | ! One steps in the C subset, that we build in the final rank array |
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| 371 | ! |
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| 372 | ! Make a copy of the rank array for the merge iteration |
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| 373 | ! |
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| 374 | JWRKT (1:LMTNA) = IRNGT (IWRKD:JINDA) |
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| 375 | ! |
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| 376 | XVALA = XDONT (JWRKT(IINDA)) |
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| 377 | XVALB = XDONT (IRNGT(IINDB)) |
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| 378 | ! |
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| 379 | Do |
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| 380 | IWRK = IWRK + 1 |
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| 381 | ! |
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| 382 | ! We still have unprocessed values in both A and B |
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| 383 | ! |
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| 384 | If (XVALA > XVALB) Then |
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| 385 | IRNGT (IWRK) = IRNGT (IINDB) |
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| 386 | IINDB = IINDB + 1 |
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| 387 | If (IINDB > IWRKF) Then |
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| 388 | ! Only A still with unprocessed values |
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| 389 | IRNGT (IWRK+1:IWRKF) = JWRKT (IINDA:LMTNA) |
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| 390 | Exit |
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| 391 | End If |
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| 392 | XVALB = XDONT (IRNGT(IINDB)) |
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| 393 | Else |
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| 394 | IRNGT (IWRK) = JWRKT (IINDA) |
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| 395 | IINDA = IINDA + 1 |
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| 396 | If (IINDA > LMTNA) Exit! Only B still with unprocessed values |
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| 397 | XVALA = XDONT (JWRKT(IINDA)) |
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| 398 | End If |
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| 399 | ! |
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| 400 | End Do |
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| 401 | End Do |
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| 402 | ! |
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| 403 | ! The Cs become As and Bs |
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| 404 | ! |
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| 405 | LMTNA = 2 * LMTNA |
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| 406 | End Do |
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| 407 | ! |
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| 408 | Return |
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| 409 | ! |
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| 410 | End Subroutine I_mrgrnk |
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| 411 | end module m_mrgrnk |
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