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C $Header: /u/gcmpack/MITgcm/pkg/cal/cal_getmonthsrec.F,v 1.2 2003/10/09 04:19:19 edhill Exp $ |
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C $Name: $ |
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|
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#include "CAL_OPTIONS.h" |
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|
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subroutine cal_GetMonthsRec( |
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O fac, first, changed, |
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O count0, count1, |
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I mytime, myiter, mythid |
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& ) |
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|
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c ================================================================== |
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c SUBROUTINE cal_GetMonthsRec |
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c ================================================================== |
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c |
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c o Given the current model time or iteration number this routine |
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c returns the corrresponding months that will have to be used in |
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c order to interpolate monthly mean fields. The routine derives |
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c from *exf_GetMonthsRec* of the external forcing package. |
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c |
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c started: Christian Eckert eckert@mit.edu 21-Apr-2000 |
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c - ported from the external forcing package and slightly |
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c modified (10 --> nmonthyear-2, 12 --> nmonthyear). |
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c |
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c changed: Patrick Heimbach heimbach@mit.edu 15-Jun-2000 |
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c - fixed bug for count1 = nmonthyear |
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c |
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c ================================================================== |
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c SUBROUTINE cal_GetMonthsRec |
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c ================================================================== |
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|
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implicit none |
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|
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c == global variables == |
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|
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#include "cal.h" |
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|
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c == routine arguments == |
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|
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_RL fac |
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logical first |
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logical changed |
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integer count0 |
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integer count1 |
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_RL mytime |
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integer myiter |
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integer mythid |
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|
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c == local variables == |
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|
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integer currentdate(4) |
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integer midtime(4) |
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integer middate(4) |
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integer tempDate(4) |
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integer middate0_1, middate0_2 |
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integer middate0(4) |
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integer middate1_1, middate1_2 |
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integer middate1(4) |
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integer prevdate(4) |
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integer shifttime(4) |
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integer startofmonth_1, startofmonth_2 |
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integer endofmonth_1, endofmonth_2 |
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integer startofmonth(4) |
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integer endofmonth(4) |
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integer difftime(4) |
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integer present |
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integer previous |
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integer next |
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integer prevcount |
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integer modelsteptime(4) |
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|
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_RL currentsecs |
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_RL prevsecs |
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_RL midsecs_np |
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_RL diffsecs |
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_RL midsecs |
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|
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c == end of interface == |
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|
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ce --> Include a check whether the right calendar is used. |
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|
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shifttime(1) = 1 |
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shifttime(2) = 0 |
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shifttime(3) = 0 |
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shifttime(4) = -1 |
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|
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call cal_TimeInterval( -modelstep, 'secs', modelsteptime, |
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& mythid ) |
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|
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c Determine the current date and the current month. |
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call cal_GetDate( myiter, mytime, currentdate, mythid ) |
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|
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present = mod(currentdate(1)/100,100) |
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startofmonth_1 = (currentdate(1)/100)*100 + 1 |
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startofmonth_2 = 0 |
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call cal_FullDate( startofmonth_1, startofmonth_2, |
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& startofmonth, mythid ) |
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|
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endofmonth_1 = (currentdate(1)/100)*100 + |
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& ndaymonth(present,currentdate(3)) |
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endofmonth_2 = 235959 |
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call cal_FullDate( endofmonth_1, endofmonth_2, |
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& endofmonth, mythid ) |
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|
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c Determine middle of current month. |
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currentsecs = float( |
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& (mod(currentdate(1),100)-1)*secondsperday + |
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& currentdate(2)/10000*secondsperhour + |
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& mod(currentdate(2)/100,100)*secondsperminute + |
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& mod(currentdate(2),100) |
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& ) |
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midsecs = float(ndaymonth(present,currentdate(3))* |
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& secondsperday/2) |
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|
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call cal_TimeInterval( midsecs, 'secs', midtime, mythid ) |
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call cal_AddTime( startofmonth, midtime, middate, mythid ) |
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call cal_AddTime( currentdate, modelsteptime, prevdate, mythid ) |
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|
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prevsecs = float( |
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& (mod(prevdate(1),100)-1)*secondsperday + |
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& prevdate(2)/10000*secondsperhour + |
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& mod(prevdate(2)/100,100)*secondsperminute + |
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& mod(prevdate(2),100) |
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& ) |
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|
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c-- Set switches for reading new records. |
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first = ((mytime - modelstart) .lt. 0.5*modelstep) |
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|
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if ( first ) then |
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changed = .false. |
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endif |
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|
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if ( currentsecs .lt. midsecs ) then |
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|
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count0 = mod(present+nmonthyear-2,nmonthyear)+1 |
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prevcount = count0 |
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|
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shifttime(1) = -shifttime(1) |
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call cal_AddTime( startofmonth, shifttime, middate0, mythid ) |
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middate0_1 = (middate0(1)/100)*100 + 1 |
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middate0_2 = 0 |
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call cal_FullDate( middate0_1, middate0_2, tempDate, |
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& mythid ) |
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|
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previous = mod(tempDate(1)/100,100) |
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|
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midsecs_np = float(ndaymonth(previous,tempDate(3))* |
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& secondsperday/2) |
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|
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call cal_TimeInterval( midsecs_np, 'secs', midtime, mythid ) |
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call cal_AddTime( tempDate, midtime, middate0, mythid ) |
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|
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count1 = present |
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|
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middate1(1) = middate(1) |
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middate1(2) = middate(2) |
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middate1(3) = middate(3) |
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middate1(4) = middate(4) |
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|
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else |
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|
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count0 = present |
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|
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if ( prevsecs .lt. midsecs ) then |
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prevcount = mod(present+nmonthyear-2,nmonthyear)+1 |
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else |
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prevcount = present |
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endif |
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|
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middate0(1) = middate(1) |
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middate0(2) = middate(2) |
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middate0(3) = middate(3) |
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middate0(4) = middate(4) |
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|
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count1 = mod(present+1,nmonthyear) |
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if ( count1 .EQ. 0 ) count1 = nmonthyear |
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|
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call cal_AddTime( endofmonth, shifttime, middate1, mythid ) |
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middate1_1 = (middate1(1)/100)*100 + 1 |
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middate1_2 = 0 |
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|
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call cal_FullDate( middate1_1, middate1_2, tempDate, |
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& mythid ) |
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next = mod(tempDate(1)/100,100) |
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midsecs_np = float(ndaymonth(next,tempDate(3))* |
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& secondsperday/2) |
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call cal_TimeInterval( midsecs_np, 'secs', midtime, mythid ) |
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call cal_AddTime( tempDate, midtime, middate1, mythid ) |
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|
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endif |
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|
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call cal_SubDates( middate1, middate0, difftime, mythid ) |
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call cal_ToSeconds( difftime, diffsecs, mythid ) |
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|
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c Set counters, switches, and the linear interpolation factor. |
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if ( (.not. first) .and. (prevcount .ne. count0) ) then |
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changed = .true. |
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else |
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changed = .false. |
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endif |
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|
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if ( currentsecs .lt. midsecs ) then |
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fac = (midsecs - currentsecs)/diffsecs |
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else |
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fac = (2.*midsecs + midsecs_np - currentsecs)/ |
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& diffsecs |
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endif |
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|
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return |
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end |
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