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!!! Downloaded from http://www.fortran-2000.com/rank/index.html |
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!!! on October 13th, 2010 |
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Module m_mrgrnk |
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! PFL 2010 Oct 13 -> |
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!Integer, Parameter :: kdp = selected_real_kind(15) |
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Integer, Parameter :: kdp = KIND(1.0D0) |
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! <- PFL 2010 Oct 13 |
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public :: mrgrnk |
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private :: kdp |
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private :: R_mrgrnk, I_mrgrnk, D_mrgrnk |
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interface mrgrnk |
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module procedure D_mrgrnk, R_mrgrnk, I_mrgrnk |
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end interface mrgrnk |
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contains |
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|
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Subroutine D_mrgrnk (XDONT, IRNGT) |
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! Subroutine Dmrgrnk (XDONT, IRNGT) |
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! __________________________________________________________ |
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! MRGRNK = Merge-sort ranking of an array |
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! For performance reasons, the first 2 passes are taken |
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! out of the standard loop, and use dedicated coding. |
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! __________________________________________________________ |
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! __________________________________________________________ |
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|
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use VarTypes |
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|
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IMPLICIT NONE |
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|
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|
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interface |
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function valid(string) result (isValid) |
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logical :: isValid |
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character(*), intent(in) :: string |
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end function valid |
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end interface |
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|
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|
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|
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Real (KREAL), Dimension (:), Intent (In) :: XDONT |
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Integer(KINT), Dimension (:), Intent (Out) :: IRNGT |
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! __________________________________________________________ |
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Real (KREAL) :: XVALA, XVALB |
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! |
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Integer(KINT), ALLOCATABLE :: JWRKT(:) ! SIZE(IRNGT) |
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Integer(KINT) :: LMTNA, LMTNC, IRNG1, IRNG2 |
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Integer(KINT) :: NVAL, IIND, IWRKD, IWRK, IWRKF, JINDA, IINDA, IINDB |
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|
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LOGICAL :: Debug |
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|
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Debug=Valid("DEBUG MRGRNK")
|
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|
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if (debug) WRITE(*,*) "================================= Entering DMRGRNK ===============" |
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! |
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NVAL = Min (SIZE(XDONT), SIZE(IRNGT)) |
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if (debug) WRITE(*,*) "D_mrgrnk",NVAL, Size(XDONT),SIZE(IRNGT) |
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Select Case (NVAL) |
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Case (:0) |
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Return |
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Case (1) |
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IRNGT (1) = 1 |
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Return |
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Case Default |
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Continue |
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End Select |
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|
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if (debug) WRITE(*,*) "D_mrgrnk, XDONT",XDONT |
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if (debug) WRITE(*,*) "D_mrgrnk, IRNGT",IRNGT |
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|
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ALLOCATE(JWRKT(SIZE(IRNGT))) |
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! |
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! Fill-in the index array, creating ordered couples |
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! |
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Do IIND = 2, NVAL, 2 |
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If (XDONT(IIND-1) <= XDONT(IIND)) Then |
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IRNGT (IIND-1) = IIND - 1 |
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IRNGT (IIND) = IIND |
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Else |
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IRNGT (IIND-1) = IIND |
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IRNGT (IIND) = IIND - 1 |
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End If |
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End Do |
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If (Modulo(NVAL, 2) /= 0) Then |
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IRNGT (NVAL) = NVAL |
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End If |
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! |
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! We will now have ordered subsets A - B - A - B - ... |
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! and merge A and B couples into C - C - ... |
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! |
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LMTNA = 2 |
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LMTNC = 4 |
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! |
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! First iteration. The length of the ordered subsets goes from 2 to 4 |
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! |
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Do |
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If (NVAL <= 2) Exit |
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! |
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! Loop on merges of A and B into C |
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! |
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Do IWRKD = 0, NVAL - 1, 4 |
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If ((IWRKD+4) > NVAL) Then |
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If ((IWRKD+2) >= NVAL) Exit |
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! |
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! 1 2 3 |
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! |
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If (XDONT(IRNGT(IWRKD+2)) <= XDONT(IRNGT(IWRKD+3))) Exit |
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! |
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! 1 3 2 |
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! |
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If (XDONT(IRNGT(IWRKD+1)) <= XDONT(IRNGT(IWRKD+3))) Then |
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IRNG2 = IRNGT (IWRKD+2) |
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IRNGT (IWRKD+2) = IRNGT (IWRKD+3) |
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IRNGT (IWRKD+3) = IRNG2 |
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! |
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! 3 1 2 |
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! |
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Else |
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IRNG1 = IRNGT (IWRKD+1) |
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IRNGT (IWRKD+1) = IRNGT (IWRKD+3) |
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IRNGT (IWRKD+3) = IRNGT (IWRKD+2) |
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IRNGT (IWRKD+2) = IRNG1 |
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End If |
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Exit |
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End If |
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! |
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! 1 2 3 4 |
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! |
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If (XDONT(IRNGT(IWRKD+2)) <= XDONT(IRNGT(IWRKD+3))) Cycle |
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! |
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! 1 3 x x |
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! |
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If (XDONT(IRNGT(IWRKD+1)) <= XDONT(IRNGT(IWRKD+3))) Then |
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IRNG2 = IRNGT (IWRKD+2) |
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IRNGT (IWRKD+2) = IRNGT (IWRKD+3) |
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If (XDONT(IRNG2) <= XDONT(IRNGT(IWRKD+4))) Then |
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! 1 3 2 4 |
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IRNGT (IWRKD+3) = IRNG2 |
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Else |
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! 1 3 4 2 |
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IRNGT (IWRKD+3) = IRNGT (IWRKD+4) |
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IRNGT (IWRKD+4) = IRNG2 |
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End If |
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! |
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! 3 x x x |
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! |
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Else |
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IRNG1 = IRNGT (IWRKD+1) |
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IRNG2 = IRNGT (IWRKD+2) |
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IRNGT (IWRKD+1) = IRNGT (IWRKD+3) |
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If (XDONT(IRNG1) <= XDONT(IRNGT(IWRKD+4))) Then |
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IRNGT (IWRKD+2) = IRNG1 |
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If (XDONT(IRNG2) <= XDONT(IRNGT(IWRKD+4))) Then |
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! 3 1 2 4 |
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IRNGT (IWRKD+3) = IRNG2 |
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Else |
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! 3 1 4 2 |
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IRNGT (IWRKD+3) = IRNGT (IWRKD+4) |
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IRNGT (IWRKD+4) = IRNG2 |
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End If |
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Else |
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! 3 4 1 2 |
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IRNGT (IWRKD+2) = IRNGT (IWRKD+4) |
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IRNGT (IWRKD+3) = IRNG1 |
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IRNGT (IWRKD+4) = IRNG2 |
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End If |
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End If |
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End Do |
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! |
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! The Cs become As and Bs |
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! |
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LMTNA = 4 |
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Exit |
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End Do |
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! |
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! Iteration loop. Each time, the length of the ordered subsets |
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! is doubled. |
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! |
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Do |
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If (LMTNA >= NVAL) Exit |
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IWRKF = 0 |
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LMTNC = 2 * LMTNC |
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! |
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! Loop on merges of A and B into C |
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! |
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Do |
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IWRK = IWRKF |
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IWRKD = IWRKF + 1 |
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JINDA = IWRKF + LMTNA |
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IWRKF = IWRKF + LMTNC |
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If (IWRKF >= NVAL) Then |
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If (JINDA >= NVAL) Exit |
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IWRKF = NVAL |
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End If |
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IINDA = 1 |
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IINDB = JINDA + 1 |
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! |
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! Shortcut for the case when the max of A is smaller |
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! than the min of B. This line may be activated when the |
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! initial set is already close to sorted. |
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! |
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! IF (XDONT(IRNGT(JINDA)) <= XDONT(IRNGT(IINDB))) CYCLE |
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! |
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! One steps in the C subset, that we build in the final rank array |
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! |
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! Make a copy of the rank array for the merge iteration |
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! |
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JWRKT (1:LMTNA) = IRNGT (IWRKD:JINDA) |
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! |
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XVALA = XDONT (JWRKT(IINDA)) |
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XVALB = XDONT (IRNGT(IINDB)) |
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! |
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Do |
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IWRK = IWRK + 1 |
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! |
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! We still have unprocessed values in both A and B |
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! |
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If (XVALA > XVALB) Then |
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IRNGT (IWRK) = IRNGT (IINDB) |
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IINDB = IINDB + 1 |
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If (IINDB > IWRKF) Then |
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! Only A still with unprocessed values |
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IRNGT (IWRK+1:IWRKF) = JWRKT (IINDA:LMTNA) |
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Exit |
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End If |
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XVALB = XDONT (IRNGT(IINDB)) |
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Else |
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IRNGT (IWRK) = JWRKT (IINDA) |
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IINDA = IINDA + 1 |
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If (IINDA > LMTNA) Exit! Only B still with unprocessed values |
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XVALA = XDONT (JWRKT(IINDA)) |
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End If |
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! |
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End Do |
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End Do |
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! |
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! The Cs become As and Bs |
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! |
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LMTNA = 2 * LMTNA |
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End Do |
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|
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DEALLOCATE(JWRKT) |
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if (debug) WRITE(*,*) "================================= Exiting DMRGRNK ===============" |
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! |
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Return |
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! |
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End Subroutine D_mrgrnk |
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|
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Subroutine R_mrgrnk (XDONT, IRNGT) |
| 249 |
! __________________________________________________________ |
| 250 |
! MRGRNK = Merge-sort ranking of an array |
| 251 |
! For performance reasons, the first 2 passes are taken |
| 252 |
! out of the standard loop, and use dedicated coding. |
| 253 |
! __________________________________________________________ |
| 254 |
! _________________________________________________________ |
| 255 |
Real, Dimension (:), Intent (In) :: XDONT |
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Integer, Dimension (:), Intent (Out) :: IRNGT |
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! __________________________________________________________ |
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Real :: XVALA, XVALB |
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! |
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Integer, Dimension (SIZE(IRNGT)) :: JWRKT |
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Integer :: LMTNA, LMTNC, IRNG1, IRNG2 |
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Integer :: NVAL, IIND, IWRKD, IWRK, IWRKF, JINDA, IINDA, IINDB |
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! |
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|
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NVAL = Min (SIZE(XDONT), SIZE(IRNGT)) |
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! if (debug) WRITE(*,*) "R_MRGRNK:", NVAL |
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Select Case (NVAL) |
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Case (:0) |
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Return |
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Case (1) |
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IRNGT (1) = 1 |
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Return |
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Case Default |
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Continue |
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End Select |
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! |
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! Fill-in the index array, creating ordered couples |
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! |
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Do IIND = 2, NVAL, 2 |
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If (XDONT(IIND-1) <= XDONT(IIND)) Then |
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IRNGT (IIND-1) = IIND - 1 |
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IRNGT (IIND) = IIND |
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Else |
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IRNGT (IIND-1) = IIND |
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IRNGT (IIND) = IIND - 1 |
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End If |
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End Do |
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If (Modulo(NVAL, 2) /= 0) Then |
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IRNGT (NVAL) = NVAL |
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End If |
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! |
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! We will now have ordered subsets A - B - A - B - ... |
| 293 |
! and merge A and B couples into C - C - ... |
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! |
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LMTNA = 2 |
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LMTNC = 4 |
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! |
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! First iteration. The length of the ordered subsets goes from 2 to 4 |
| 299 |
! |
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Do |
| 301 |
If (NVAL <= 2) Exit |
| 302 |
! |
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! Loop on merges of A and B into C |
| 304 |
! |
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Do IWRKD = 0, NVAL - 1, 4 |
| 306 |
If ((IWRKD+4) > NVAL) Then |
| 307 |
If ((IWRKD+2) >= NVAL) Exit |
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! |
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! 1 2 3 |
| 310 |
! |
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If (XDONT(IRNGT(IWRKD+2)) <= XDONT(IRNGT(IWRKD+3))) Exit |
| 312 |
! |
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! 1 3 2 |
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! |
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If (XDONT(IRNGT(IWRKD+1)) <= XDONT(IRNGT(IWRKD+3))) Then |
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IRNG2 = IRNGT (IWRKD+2) |
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IRNGT (IWRKD+2) = IRNGT (IWRKD+3) |
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IRNGT (IWRKD+3) = IRNG2 |
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! |
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! 3 1 2 |
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! |
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Else |
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IRNG1 = IRNGT (IWRKD+1) |
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IRNGT (IWRKD+1) = IRNGT (IWRKD+3) |
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IRNGT (IWRKD+3) = IRNGT (IWRKD+2) |
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IRNGT (IWRKD+2) = IRNG1 |
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End If |
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Exit |
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End If |
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! |
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! 1 2 3 4 |
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! |
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If (XDONT(IRNGT(IWRKD+2)) <= XDONT(IRNGT(IWRKD+3))) Cycle |
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! |
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! 1 3 x x |
| 336 |
! |
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If (XDONT(IRNGT(IWRKD+1)) <= XDONT(IRNGT(IWRKD+3))) Then |
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IRNG2 = IRNGT (IWRKD+2) |
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IRNGT (IWRKD+2) = IRNGT (IWRKD+3) |
| 340 |
If (XDONT(IRNG2) <= XDONT(IRNGT(IWRKD+4))) Then |
| 341 |
! 1 3 2 4 |
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IRNGT (IWRKD+3) = IRNG2 |
| 343 |
Else |
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! 1 3 4 2 |
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IRNGT (IWRKD+3) = IRNGT (IWRKD+4) |
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IRNGT (IWRKD+4) = IRNG2 |
| 347 |
End If |
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! |
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! 3 x x x |
| 350 |
! |
| 351 |
Else |
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IRNG1 = IRNGT (IWRKD+1) |
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IRNG2 = IRNGT (IWRKD+2) |
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IRNGT (IWRKD+1) = IRNGT (IWRKD+3) |
| 355 |
If (XDONT(IRNG1) <= XDONT(IRNGT(IWRKD+4))) Then |
| 356 |
IRNGT (IWRKD+2) = IRNG1 |
| 357 |
If (XDONT(IRNG2) <= XDONT(IRNGT(IWRKD+4))) Then |
| 358 |
! 3 1 2 4 |
| 359 |
IRNGT (IWRKD+3) = IRNG2 |
| 360 |
Else |
| 361 |
! 3 1 4 2 |
| 362 |
IRNGT (IWRKD+3) = IRNGT (IWRKD+4) |
| 363 |
IRNGT (IWRKD+4) = IRNG2 |
| 364 |
End If |
| 365 |
Else |
| 366 |
! 3 4 1 2 |
| 367 |
IRNGT (IWRKD+2) = IRNGT (IWRKD+4) |
| 368 |
IRNGT (IWRKD+3) = IRNG1 |
| 369 |
IRNGT (IWRKD+4) = IRNG2 |
| 370 |
End If |
| 371 |
End If |
| 372 |
End Do |
| 373 |
! |
| 374 |
! The Cs become As and Bs |
| 375 |
! |
| 376 |
LMTNA = 4 |
| 377 |
Exit |
| 378 |
End Do |
| 379 |
! |
| 380 |
! Iteration loop. Each time, the length of the ordered subsets |
| 381 |
! is doubled. |
| 382 |
! |
| 383 |
Do |
| 384 |
If (LMTNA >= NVAL) Exit |
| 385 |
IWRKF = 0 |
| 386 |
LMTNC = 2 * LMTNC |
| 387 |
! |
| 388 |
! Loop on merges of A and B into C |
| 389 |
! |
| 390 |
Do |
| 391 |
IWRK = IWRKF |
| 392 |
IWRKD = IWRKF + 1 |
| 393 |
JINDA = IWRKF + LMTNA |
| 394 |
IWRKF = IWRKF + LMTNC |
| 395 |
If (IWRKF >= NVAL) Then |
| 396 |
If (JINDA >= NVAL) Exit |
| 397 |
IWRKF = NVAL |
| 398 |
End If |
| 399 |
IINDA = 1 |
| 400 |
IINDB = JINDA + 1 |
| 401 |
! |
| 402 |
! Shortcut for the case when the max of A is smaller |
| 403 |
! than the min of B. This line may be activated when the |
| 404 |
! initial set is already close to sorted. |
| 405 |
! |
| 406 |
! IF (XDONT(IRNGT(JINDA)) <= XDONT(IRNGT(IINDB))) CYCLE |
| 407 |
! |
| 408 |
! One steps in the C subset, that we build in the final rank array |
| 409 |
! |
| 410 |
! Make a copy of the rank array for the merge iteration |
| 411 |
! |
| 412 |
JWRKT (1:LMTNA) = IRNGT (IWRKD:JINDA) |
| 413 |
! |
| 414 |
XVALA = XDONT (JWRKT(IINDA)) |
| 415 |
XVALB = XDONT (IRNGT(IINDB)) |
| 416 |
! |
| 417 |
Do |
| 418 |
IWRK = IWRK + 1 |
| 419 |
! |
| 420 |
! We still have unprocessed values in both A and B |
| 421 |
! |
| 422 |
If (XVALA > XVALB) Then |
| 423 |
IRNGT (IWRK) = IRNGT (IINDB) |
| 424 |
IINDB = IINDB + 1 |
| 425 |
If (IINDB > IWRKF) Then |
| 426 |
! Only A still with unprocessed values |
| 427 |
IRNGT (IWRK+1:IWRKF) = JWRKT (IINDA:LMTNA) |
| 428 |
Exit |
| 429 |
End If |
| 430 |
XVALB = XDONT (IRNGT(IINDB)) |
| 431 |
Else |
| 432 |
IRNGT (IWRK) = JWRKT (IINDA) |
| 433 |
IINDA = IINDA + 1 |
| 434 |
If (IINDA > LMTNA) Exit! Only B still with unprocessed values |
| 435 |
XVALA = XDONT (JWRKT(IINDA)) |
| 436 |
End If |
| 437 |
! |
| 438 |
End Do |
| 439 |
End Do |
| 440 |
! |
| 441 |
! The Cs become As and Bs |
| 442 |
! |
| 443 |
LMTNA = 2 * LMTNA |
| 444 |
End Do |
| 445 |
! |
| 446 |
Return |
| 447 |
! |
| 448 |
End Subroutine R_mrgrnk |
| 449 |
Subroutine I_mrgrnk (XDONT, IRNGT) |
| 450 |
! __________________________________________________________ |
| 451 |
! MRGRNK = Merge-sort ranking of an array |
| 452 |
! For performance reasons, the first 2 passes are taken |
| 453 |
! out of the standard loop, and use dedicated coding. |
| 454 |
! __________________________________________________________ |
| 455 |
! __________________________________________________________ |
| 456 |
Integer, Dimension (:), Intent (In) :: XDONT |
| 457 |
Integer, Dimension (:), Intent (Out) :: IRNGT |
| 458 |
! __________________________________________________________ |
| 459 |
Integer :: XVALA, XVALB |
| 460 |
! |
| 461 |
Integer, Dimension (SIZE(IRNGT)) :: JWRKT |
| 462 |
Integer :: LMTNA, LMTNC, IRNG1, IRNG2 |
| 463 |
Integer :: NVAL, IIND, IWRKD, IWRK, IWRKF, JINDA, IINDA, IINDB |
| 464 |
! |
| 465 |
NVAL = Min (SIZE(XDONT), SIZE(IRNGT)) |
| 466 |
! WRITE(*,*) "I_mrgrnk",NVAL |
| 467 |
Select Case (NVAL) |
| 468 |
Case (:0) |
| 469 |
Return |
| 470 |
Case (1) |
| 471 |
IRNGT (1) = 1 |
| 472 |
Return |
| 473 |
Case Default |
| 474 |
Continue |
| 475 |
End Select |
| 476 |
! |
| 477 |
! Fill-in the index array, creating ordered couples |
| 478 |
! |
| 479 |
Do IIND = 2, NVAL, 2 |
| 480 |
If (XDONT(IIND-1) <= XDONT(IIND)) Then |
| 481 |
IRNGT (IIND-1) = IIND - 1 |
| 482 |
IRNGT (IIND) = IIND |
| 483 |
Else |
| 484 |
IRNGT (IIND-1) = IIND |
| 485 |
IRNGT (IIND) = IIND - 1 |
| 486 |
End If |
| 487 |
End Do |
| 488 |
If (Modulo(NVAL, 2) /= 0) Then |
| 489 |
IRNGT (NVAL) = NVAL |
| 490 |
End If |
| 491 |
! |
| 492 |
! We will now have ordered subsets A - B - A - B - ... |
| 493 |
! and merge A and B couples into C - C - ... |
| 494 |
! |
| 495 |
LMTNA = 2 |
| 496 |
LMTNC = 4 |
| 497 |
! |
| 498 |
! First iteration. The length of the ordered subsets goes from 2 to 4 |
| 499 |
! |
| 500 |
Do |
| 501 |
If (NVAL <= 2) Exit |
| 502 |
! |
| 503 |
! Loop on merges of A and B into C |
| 504 |
! |
| 505 |
Do IWRKD = 0, NVAL - 1, 4 |
| 506 |
If ((IWRKD+4) > NVAL) Then |
| 507 |
If ((IWRKD+2) >= NVAL) Exit |
| 508 |
! |
| 509 |
! 1 2 3 |
| 510 |
! |
| 511 |
If (XDONT(IRNGT(IWRKD+2)) <= XDONT(IRNGT(IWRKD+3))) Exit |
| 512 |
! |
| 513 |
! 1 3 2 |
| 514 |
! |
| 515 |
If (XDONT(IRNGT(IWRKD+1)) <= XDONT(IRNGT(IWRKD+3))) Then |
| 516 |
IRNG2 = IRNGT (IWRKD+2) |
| 517 |
IRNGT (IWRKD+2) = IRNGT (IWRKD+3) |
| 518 |
IRNGT (IWRKD+3) = IRNG2 |
| 519 |
! |
| 520 |
! 3 1 2 |
| 521 |
! |
| 522 |
Else |
| 523 |
IRNG1 = IRNGT (IWRKD+1) |
| 524 |
IRNGT (IWRKD+1) = IRNGT (IWRKD+3) |
| 525 |
IRNGT (IWRKD+3) = IRNGT (IWRKD+2) |
| 526 |
IRNGT (IWRKD+2) = IRNG1 |
| 527 |
End If |
| 528 |
Exit |
| 529 |
End If |
| 530 |
! |
| 531 |
! 1 2 3 4 |
| 532 |
! |
| 533 |
If (XDONT(IRNGT(IWRKD+2)) <= XDONT(IRNGT(IWRKD+3))) Cycle |
| 534 |
! |
| 535 |
! 1 3 x x |
| 536 |
! |
| 537 |
If (XDONT(IRNGT(IWRKD+1)) <= XDONT(IRNGT(IWRKD+3))) Then |
| 538 |
IRNG2 = IRNGT (IWRKD+2) |
| 539 |
IRNGT (IWRKD+2) = IRNGT (IWRKD+3) |
| 540 |
If (XDONT(IRNG2) <= XDONT(IRNGT(IWRKD+4))) Then |
| 541 |
! 1 3 2 4 |
| 542 |
IRNGT (IWRKD+3) = IRNG2 |
| 543 |
Else |
| 544 |
! 1 3 4 2 |
| 545 |
IRNGT (IWRKD+3) = IRNGT (IWRKD+4) |
| 546 |
IRNGT (IWRKD+4) = IRNG2 |
| 547 |
End If |
| 548 |
! |
| 549 |
! 3 x x x |
| 550 |
! |
| 551 |
Else |
| 552 |
IRNG1 = IRNGT (IWRKD+1) |
| 553 |
IRNG2 = IRNGT (IWRKD+2) |
| 554 |
IRNGT (IWRKD+1) = IRNGT (IWRKD+3) |
| 555 |
If (XDONT(IRNG1) <= XDONT(IRNGT(IWRKD+4))) Then |
| 556 |
IRNGT (IWRKD+2) = IRNG1 |
| 557 |
If (XDONT(IRNG2) <= XDONT(IRNGT(IWRKD+4))) Then |
| 558 |
! 3 1 2 4 |
| 559 |
IRNGT (IWRKD+3) = IRNG2 |
| 560 |
Else |
| 561 |
! 3 1 4 2 |
| 562 |
IRNGT (IWRKD+3) = IRNGT (IWRKD+4) |
| 563 |
IRNGT (IWRKD+4) = IRNG2 |
| 564 |
End If |
| 565 |
Else |
| 566 |
! 3 4 1 2 |
| 567 |
IRNGT (IWRKD+2) = IRNGT (IWRKD+4) |
| 568 |
IRNGT (IWRKD+3) = IRNG1 |
| 569 |
IRNGT (IWRKD+4) = IRNG2 |
| 570 |
End If |
| 571 |
End If |
| 572 |
End Do |
| 573 |
! |
| 574 |
! The Cs become As and Bs |
| 575 |
! |
| 576 |
LMTNA = 4 |
| 577 |
Exit |
| 578 |
End Do |
| 579 |
! |
| 580 |
! Iteration loop. Each time, the length of the ordered subsets |
| 581 |
! is doubled. |
| 582 |
! |
| 583 |
Do |
| 584 |
If (LMTNA >= NVAL) Exit |
| 585 |
IWRKF = 0 |
| 586 |
LMTNC = 2 * LMTNC |
| 587 |
! |
| 588 |
! Loop on merges of A and B into C |
| 589 |
! |
| 590 |
Do |
| 591 |
IWRK = IWRKF |
| 592 |
IWRKD = IWRKF + 1 |
| 593 |
JINDA = IWRKF + LMTNA |
| 594 |
IWRKF = IWRKF + LMTNC |
| 595 |
If (IWRKF >= NVAL) Then |
| 596 |
If (JINDA >= NVAL) Exit |
| 597 |
IWRKF = NVAL |
| 598 |
End If |
| 599 |
IINDA = 1 |
| 600 |
IINDB = JINDA + 1 |
| 601 |
! |
| 602 |
! Shortcut for the case when the max of A is smaller |
| 603 |
! than the min of B. This line may be activated when the |
| 604 |
! initial set is already close to sorted. |
| 605 |
! |
| 606 |
! IF (XDONT(IRNGT(JINDA)) <= XDONT(IRNGT(IINDB))) CYCLE |
| 607 |
! |
| 608 |
! One steps in the C subset, that we build in the final rank array |
| 609 |
! |
| 610 |
! Make a copy of the rank array for the merge iteration |
| 611 |
! |
| 612 |
JWRKT (1:LMTNA) = IRNGT (IWRKD:JINDA) |
| 613 |
! |
| 614 |
XVALA = XDONT (JWRKT(IINDA)) |
| 615 |
XVALB = XDONT (IRNGT(IINDB)) |
| 616 |
! |
| 617 |
Do |
| 618 |
IWRK = IWRK + 1 |
| 619 |
! |
| 620 |
! We still have unprocessed values in both A and B |
| 621 |
! |
| 622 |
If (XVALA > XVALB) Then |
| 623 |
IRNGT (IWRK) = IRNGT (IINDB) |
| 624 |
IINDB = IINDB + 1 |
| 625 |
If (IINDB > IWRKF) Then |
| 626 |
! Only A still with unprocessed values |
| 627 |
IRNGT (IWRK+1:IWRKF) = JWRKT (IINDA:LMTNA) |
| 628 |
Exit |
| 629 |
End If |
| 630 |
XVALB = XDONT (IRNGT(IINDB)) |
| 631 |
Else |
| 632 |
IRNGT (IWRK) = JWRKT (IINDA) |
| 633 |
IINDA = IINDA + 1 |
| 634 |
If (IINDA > LMTNA) Exit! Only B still with unprocessed values |
| 635 |
XVALA = XDONT (JWRKT(IINDA)) |
| 636 |
End If |
| 637 |
! |
| 638 |
End Do |
| 639 |
End Do |
| 640 |
! |
| 641 |
! The Cs become As and Bs |
| 642 |
! |
| 643 |
LMTNA = 2 * LMTNA |
| 644 |
End Do |
| 645 |
! |
| 646 |
Return |
| 647 |
! |
| 648 |
End Subroutine I_mrgrnk |
| 649 |
end module m_mrgrnk |