pkg/cal/cal_stepsforday.F

C $Header: /u/gcmpack/development/heimbach/ecco_env/pkg/cal/cal_stepsforday.F,v 1.4 2001/02/02 16:57:22 heimbach Exp $

#include "CAL_CPPOPTIONS.h"

      subroutine cal_StepsForDay(
     I                            iday,
     O                            firststep,
     O                            laststep,
     O                            nsteps,
     I                            mythid
     &                          )

c     ==================================================================
c     SUBROUTINE cal_StepsForDay
c     ==================================================================
c
c     o Given the current day of the integration this routine returns
c       first, the last and the number of model steps the will have to
c       be performed.
c
c       This routine also checks consistency of variables quite
c       extensively.
c
c     started: Christian Eckert eckert@mit.edu  06-Apr-2000
c
c     changed: 
c
c     ==================================================================
c     SUBROUTINE cal_StepsForDay
c     ==================================================================

      implicit none

c     == global variables ==

#include "cal.h"

c     == routine arguments ==

      integer iday
      integer firststep
      integer laststep
      integer nsteps
      integer mythid

c     == local variables ==

      integer ierr
      integer mdstep
      integer numdays
      integer numsteps
      integer frac1
      integer frac2
      integer frac3
      integer frac4
      integer fullsteps
      integer firstyear
      integer firstmonth
      integer firstday
      integer lyfirst
      integer startsecs
      integer lastday
      integer endsecs

c     == external ==

      external cal_IntDays
      integer  cal_IntDays
      external cal_IsLeap
      integer  cal_IsLeap

c     == end of interface ==

      numdays    = cal_IntDays( mythid )
      lyfirst    = cal_IsLeap( firstyear, mythid )

      mdstep     = int(modelstep)

      firstyear  = modelstartdate(1)/10000
      firstmonth = mod(modelstartdate(1)/100,100)
      firstday   = mod(modelstartdate(1),100)
      lastday    = mod(modelenddate(1),100)

      startsecs  = (modelstartdate(2)/10000)*secondsperhour +
     &             mod(modelstartdate(2)/100,100)*secondsperminute +
     &             mod(modelstartdate(2),100)
      endsecs    = (modelenddate(2)/10000)*secondsperhour +
     &             mod(modelenddate(2)/100,100)*secondsperminute +
     &             mod(modelenddate(2),100)

      if ( numdays .eq. 1 ) then
        if ( iday .eq. firstday ) then
c--       Get the number of steps in the first day.
          if ( firstday .eq. lastday ) then
            firststep = 1
            laststep  = modelintsteps
          else if ( mod(firstday+1,ndaymonth(firstmonth,lyfirst)) .eq.
     &              lastday ) then
c--         This can only happen if we end at midnight of the next day.
            if ( modelenddate(2) .eq. 0 ) then
              firststep = 1
              laststep  = modelintsteps
c--           Note: This holds only if modelenddate was determined
c--                 such that it coincides with the model's final time.
            else
c--           We do not end at midnight of the first day of
c--           the next month.
              ierr = 2604
              call cal_PrintError( ierr, mythid )
              stop ' stopped in cal_StepsForDay.'
            endif
          else
c--         The first and the last day are inconsistent with iday.
            ierr = 2603
            call cal_PrintError( ierr, mythid )
            stop ' stopped in cal_StepsForDay.'
          endif
        else
c--       The variables numdays and iday are inconsistent;
c--       ( iday .gt. numdays ).
          ierr = 2602
          call cal_PrintError( ierr, mythid )
          stop ' stopped in cal_StepsForDay.'
        endif

      else if ( numdays .gt. 1 ) then
c--     More than one day of integration.
        if ( iday .eq. 1 ) then
          firststep = 1
          laststep  = int((secondsperday - startsecs)/mdstep)
        else if ( ( iday .gt. 1      ) .and.
     &            ( iday .lt. numdays) ) then
c--       Somewhere between first and last month.
c--       The first steps in iday.
          fullsteps = int((secondsperday - startsecs)/mdstep)
          numsteps  = fullsteps
c--       What's left in the first day (frac1).
          frac1     = (secondsperday - startsecs) - fullsteps*mdstep
          fullsteps = int(secondsperday/modelstep)
c--       What's left in a complete day (frac2).
          frac2     = secondsperday - fullsteps*mdstep
c--       What's left up to the current day (frac3).
          frac3     = frac1 + frac2*(iday - 1)
          numsteps  = numsteps + (iday - 1)*fullsteps +
     &                frac3/mdstep
          laststep  = numsteps
          firststep = laststep - secondsperday/mdstep + 1

        else if ( iday .eq. numdays ) then
c--       The last day of integration.
c--       The first step in iday.
          fullsteps = int((secondsperday - startsecs)/mdstep)
          numsteps  = fullsteps
c--       What's left in the first day (frac1).
          frac1     = (secondsperday - startsecs) - fullsteps*mdstep
          fullsteps = int(secondsperday/modelstep)
c--       What's left in a complete day (frac2).
          frac2     = secondsperday - fullsteps*mdstep
c--       What's left up to the day before the last (frac3).
          frac3     = frac1 + frac2*(iday - 2)
          numsteps  = numsteps + (iday - 2)*fullsteps
c--       The last step in iday.
          if ( modelenddate(2) .eq. 0 ) then
c--         This can only happen if we end at midnight of the next day.
            laststep  = numsteps + fullsteps
            firststep = numsteps + 1
c--         Note: There should be no fraction left
c--               ( mod(frac3,mdstep) = frac3/mdstep ) if modelenddate
c--               is based on an integral number of timesteps.
          else
            frac4     = frac3 + endsecs
            numsteps  = numsteps + frac4/mdstep
            laststep  = numsteps

c--         Note: There should be no fraction left
c--               ( mod(frac4,mdstep = frac4/mdstep ) if modelenddate
c--               is based on an integral number of timesteps.

            firststep = laststep - endsecs/mdstep + 1
          endif
        else
c--       The variables iday and numdays are inconsistent.
          ierr = 2605
          call cal_PrintError( ierr, mythid )
          stop ' stopped in cal_DaysForMonth.'
        endif
      else
c--     The number of days to integrate is wrong; check cal_IntDays.
        ierr = 2601
        call cal_PrintError( ierr, mythid )
        stop ' stopped in cal_StepsForDay.'
      endif

c--   The number of days to integrate in the given month.
      nsteps = laststep - firststep + 1

      return
      end

1	C $Header: /u/gcmpack/development/heimbach/ecco_env/pkg/cal/cal_stepsforday.F,v 1.4 2001/02/02 16:57:22 heimbach Exp $
2
3	#include "CAL_CPPOPTIONS.h"
4
5	subroutine cal_StepsForDay(
6	I iday,
7	O firststep,
8	O laststep,
9	O nsteps,
10	I mythid
11	& )
12
13	c ==================================================================
14	c SUBROUTINE cal_StepsForDay
15	c ==================================================================
16	c
17	c o Given the current day of the integration this routine returns
18	c first, the last and the number of model steps the will have to
19	c be performed.
20	c
21	c This routine also checks consistency of variables quite
22	c extensively.
23	c
24	c started: Christian Eckert eckert@mit.edu 06-Apr-2000
25	c
26	c changed:
27	c
28	c ==================================================================
29	c SUBROUTINE cal_StepsForDay
30	c ==================================================================
31
32	implicit none
33
34	c == global variables ==
35
36	#include "cal.h"
37
38	c == routine arguments ==
39
40	integer iday
41	integer firststep
42	integer laststep
43	integer nsteps
44	integer mythid
45
46	c == local variables ==
47
48	integer ierr
49	integer mdstep
50	integer numdays
51	integer numsteps
52	integer frac1
53	integer frac2
54	integer frac3
55	integer frac4
56	integer fullsteps
57	integer firstyear
58	integer firstmonth
59	integer firstday
60	integer lyfirst
61	integer startsecs
62	integer lastday
63	integer endsecs
64
65	c == external ==
66
67	external cal_IntDays
68	integer cal_IntDays
69	external cal_IsLeap
70	integer cal_IsLeap
71
72	c == end of interface ==
73
74	numdays = cal_IntDays( mythid )
75	lyfirst = cal_IsLeap( firstyear, mythid )
76
77	mdstep = int(modelstep)
78
79	firstyear = modelstartdate(1)/10000
80	firstmonth = mod(modelstartdate(1)/100,100)
81	firstday = mod(modelstartdate(1),100)
82	lastday = mod(modelenddate(1),100)
83
84	startsecs = (modelstartdate(2)/10000)*secondsperhour +
85	& mod(modelstartdate(2)/100,100)*secondsperminute +
86	& mod(modelstartdate(2),100)
87	endsecs = (modelenddate(2)/10000)*secondsperhour +
88	& mod(modelenddate(2)/100,100)*secondsperminute +
89	& mod(modelenddate(2),100)
90
91	if ( numdays .eq. 1 ) then
92	if ( iday .eq. firstday ) then
93	c-- Get the number of steps in the first day.
94	if ( firstday .eq. lastday ) then
95	firststep = 1
96	laststep = modelintsteps
97	else if ( mod(firstday+1,ndaymonth(firstmonth,lyfirst)) .eq.
98	& lastday ) then
99	c-- This can only happen if we end at midnight of the next day.
100	if ( modelenddate(2) .eq. 0 ) then
101	firststep = 1
102	laststep = modelintsteps
103	c-- Note: This holds only if modelenddate was determined
104	c-- such that it coincides with the model's final time.
105	else
106	c-- We do not end at midnight of the first day of
107	c-- the next month.
108	ierr = 2604
109	call cal_PrintError( ierr, mythid )
110	stop ' stopped in cal_StepsForDay.'
111	endif
112	else
113	c-- The first and the last day are inconsistent with iday.
114	ierr = 2603
115	call cal_PrintError( ierr, mythid )
116	stop ' stopped in cal_StepsForDay.'
117	endif
118	else
119	c-- The variables numdays and iday are inconsistent;
120	c-- ( iday .gt. numdays ).
121	ierr = 2602
122	call cal_PrintError( ierr, mythid )
123	stop ' stopped in cal_StepsForDay.'
124	endif
125
126	else if ( numdays .gt. 1 ) then
127	c-- More than one day of integration.
128	if ( iday .eq. 1 ) then
129	firststep = 1
130	laststep = int((secondsperday - startsecs)/mdstep)
131	else if ( ( iday .gt. 1 ) .and.
132	& ( iday .lt. numdays) ) then
133	c-- Somewhere between first and last month.
134	c-- The first steps in iday.
135	fullsteps = int((secondsperday - startsecs)/mdstep)
136	numsteps = fullsteps
137	c-- What's left in the first day (frac1).
138	frac1 = (secondsperday - startsecs) - fullsteps*mdstep
139	fullsteps = int(secondsperday/modelstep)
140	c-- What's left in a complete day (frac2).
141	frac2 = secondsperday - fullsteps*mdstep
142	c-- What's left up to the current day (frac3).
143	frac3 = frac1 + frac2*(iday - 1)
144	numsteps = numsteps + (iday - 1)*fullsteps +
145	& frac3/mdstep
146	laststep = numsteps
147	firststep = laststep - secondsperday/mdstep + 1
148
149	else if ( iday .eq. numdays ) then
150	c-- The last day of integration.
151	c-- The first step in iday.
152	fullsteps = int((secondsperday - startsecs)/mdstep)
153	numsteps = fullsteps
154	c-- What's left in the first day (frac1).
155	frac1 = (secondsperday - startsecs) - fullsteps*mdstep
156	fullsteps = int(secondsperday/modelstep)
157	c-- What's left in a complete day (frac2).
158	frac2 = secondsperday - fullsteps*mdstep
159	c-- What's left up to the day before the last (frac3).
160	frac3 = frac1 + frac2*(iday - 2)
161	numsteps = numsteps + (iday - 2)*fullsteps
162	c-- The last step in iday.
163	if ( modelenddate(2) .eq. 0 ) then
164	c-- This can only happen if we end at midnight of the next day.
165	laststep = numsteps + fullsteps
166	firststep = numsteps + 1
167	c-- Note: There should be no fraction left
168	c-- ( mod(frac3,mdstep) = frac3/mdstep ) if modelenddate
169	c-- is based on an integral number of timesteps.
170	else
171	frac4 = frac3 + endsecs
172	numsteps = numsteps + frac4/mdstep
173	laststep = numsteps
174
175	c-- Note: There should be no fraction left
176	c-- ( mod(frac4,mdstep = frac4/mdstep ) if modelenddate
177	c-- is based on an integral number of timesteps.
178
179	firststep = laststep - endsecs/mdstep + 1
180	endif
181	else
182	c-- The variables iday and numdays are inconsistent.
183	ierr = 2605
184	call cal_PrintError( ierr, mythid )
185	stop ' stopped in cal_DaysForMonth.'
186	endif
187	else
188	c-- The number of days to integrate is wrong; check cal_IntDays.
189	ierr = 2601
190	call cal_PrintError( ierr, mythid )
191	stop ' stopped in cal_StepsForDay.'
192	endif
193
194	c-- The number of days to integrate in the given month.
195	nsteps = laststep - firststep + 1
196
197	return
198	end
199