xrjjm%scint.span@VLSI.JPL.NASA.GOV (08/05/87)
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*Site: NASA Goddard Space Flight Center - Greenbelt, Maryland, USA.
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*From: John J. McMahon, Systems Programmer, STX - ST Systems Corporation.
*Project: COBE Science Data Room (CSDR), Code 401.1
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Lately I have been playing with the various F$xTIME commands that DCL
offers and I have noticed a couple of things that either are shortcomings,
or more likely things I have missed somewhere.
The first is converting a "Comparison" time to an "Absolute" time. The
only difference I can find is that "Comparison" times use numeric
months, while "Absolute" uses JAN, FEB, MAR... etc.
I have a routine that wants to calculate a date 2 months back. I take
an Absolute time as input, Convert it to Comparison, perform a calculation
(Month - 2)... then what ? How do I convert it back to absolute ? (In DCL).
I have considered using Delta times (Subtract 60 days or something similar)
but that doesn't fit my bill for accuracy. I ruled out a HLL because this was
supposed to be a Quick and Dirty job...
My second time question is, how does one calculate a delta time between two
dates (also in DCL). I am primarily concerned with the number of days
between two dates, but knowing how to figure it out to the second would be
nice.
I have solved both of these problems already... I am just looking for the
more elegant solution.
--- Ok, next problem... Lately I haven't seen any mail from INFO-VAX, and I
am trying to track down all of the possible failure points. If you have
have sent mail to INFO-VAX lately, AND gotten a 'failed' message on my
address (xrjjm%csdr.span@jpl-vlsi.arpa) could you try and send me a
copy of the mail headers, or send me some mail describing the problem.
(If you can't get it to the address above, send it to ZMJJM@SCFVM.BITNET,
Internet: ZMJJM@SCFVM.BITNET@WISCVM.WISC.EDU)
Thanks & Regards,
^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v^v
John J. McMahon (Fast-Eddie)
Disclaimer: Views expressed in this letter are my own,
and are not meant to represent the views of my employers.u3369429@murdu.OZ (Michael Bednarek) (08/07/87)
In article <870805075119.03q@VLSI.JPL.NASA.GOV> xrjjm%scint.span@VLSI.JPL.NASA.GOV writes: > [Things about F$CVTIME] >I have a routine that wants to calculate a date 2 months back. I take >an Absolute time as input, Convert it to Comparison, perform a calculation >(Month - 2)... then what ? How do I convert it back to absolute ? (In DCL). >I have considered using Delta times (Subtract 60 days or something similar) >but that doesn't fit my bill for accuracy. I ruled out a HLL because this was >supposed to be a Quick and Dirty job... Well, this might not be the precise answer to your problems, but as I didn't feel much like doing something productive this morning, I translated two subroutines which deal with dates from Fortran to DCL. One, JULIAN, takes a Gregorian date (dd-MON-yyyy) and returns a) the Julian daynumber within that year, b) a Julian day number since 1-Jan-0001. These day numbers can then be used to perform some calculations. Its sister (brother ?) routine, GREGOR, takes b) from JULIAN and returns a Gregorian date. Now, anybody interested in a routine which calculates the date of easter (a la D. Knuth) for any year? ....................... Cut between dotted lines and save ...................... $!.............................................................................. $! VAX/VMS archive file created by VMS_SHAR V-4.03 05-Aug-1987 $! which was written by Michael Bednarek (U3369429@ucsvc.dn.mu.oz.au) $! To unpack, simply save and execute (@) this file. $! $! This archive was created by U3369429 (Michael Bednarek) $! on Friday 7-AUG-1987 15:50:09.27 $! $! It contains the following 1 file: $! JULGREG.COM $!============================================================================== $ Set Symbol/Scope=(NoLocal,NoGlobal) $ Version=F$GetSYI("VERSION") ! See what VMS version we have here: $ If Version.ges."V4.4" then goto Version_OK $ Write SYS$Output "Sorry, you are running VMS ",Version, - ", but this procedure requires V4.4 or higher." $ Exit 44 $Version_OK: CR[0,8]=13 $ Pass_or_Failed="failed!,passed." $ Goto Start $Convert_File: $ Read/Time_Out=0/Error=No_Error1/Prompt="creating ''File_is'" SYS$Command ddd $No_Error1: Define/User_Mode SYS$Output NL: $ Edit/TPU/NoSection/NoDisplay/Command=SYS$Input/Output='File_is' - VMS_SHAR_DUMMY.DUMMY f:=Get_Info(Command_Line,"File_Name");b:=Create_Buffer("",f); o:=Get_Info(Command_Line,"Output_File");Set (Output_File,b,o); Position (Beginning_of(b));Loop x:=Erase_Character(1); Loop ExitIf x<>"V"; Move_Vertical(1);x:=Erase_Character(1);Append_Line;Move_Horizontal (-Current_Offset);EndLoop;Move_Vertical(1);ExitIf Mark(None)=End_of(b) EndLoop;Exit; $ Delete VMS_SHAR_DUMMY.DUMMY;* $ Checksum 'File_is $ Success=F$Element(Check_Sum_is.eq.CHECKSUM$CHECKSUM,",",Pass_or_Failed)+CR $ Read/Time_Out=0/Error=No_Error2/Prompt=" CHECKSUM ''Success'" SYS$Command ddd $No_Error2: Return $Start: $ File_is="JULGREG.COM" $ Check_Sum_is=1148729702 $ Copy SYS$Input VMS_SHAR_DUMMY.DUMMY X$ Verify='F$Verify(0) X$! Playing around with Julian and Gregorian dates X$ Facility_Name= "JULGREG" X$ Facility_Version= "V-1.00 07-Aug-1987" X$! X$!Michael Bednarek u3369429@{murdu.oz.au | ucsvc.dn.mu.oz.au} X$!Institute of Applied Economic -- or -- X$! and Social Research (IAESR) ...{UUNET.UU.NET | seismo.CSS.GOV}!munnari! X$!Melbourne University {murdu.oz | ucsvc.dn.mu.oz}!u3369429 X$!Parkville 3052, Phone : +61 3 344 5744 X$!AUSTRALIA X$! X$! Copyright (c) 1987, by Michael Bednarek X$! The distribution of this file is unrestricted as long as this notice X$! remains intact. X$! X$! Usage: @JULGREG Date1 Date2 X$! X$ Say="Write SYS$Output" X$ Ask="Inquire/NoPunctuation" X$ Say Facility_Name," ",Facility_Version X$ Say "" X$! X$ On Warning then Exit X$ If P1.eqs."" then Ask P1 "Enter Date 1: " X$ P1=F$CVTime(P1,"Absolute") X$ If P2.eqs."" then Ask P2 "Enter Date 2: " X$ P2=F$CVTime(P2,"Absolute") X$ Call Julian "''P1'" YJDay1 AJDay1 X$ Call Julian "''P2'" YJDay2 AJDay2 X$ Say F$FAO("The difference is !SL day!%S",AJDay2-AJDay1) X$! Testing Gregor: X$ Call Gregor 'AJDay1 Date1 X$ Call Gregor 'AJDay2 Date2 X$ Say "GREGOR returns: ",Date1," and ",Date2 X$ Exit X$Julian: Subroutine X$ On Warning then Exit X$! Converts Gregorian Date into Julian Day X$! This is a straight translation from an old Fortran routine of mine. X$ M2=" 0,31,59,90,120,151,181,212,243,273,304,334" X$! Input: X$! P1 = Date in absolute format as returned from F$CVTIME X$! X$! Output: X$! P2 = YJDay = Julian Day in this year X$! P3 = AJDay = Julian Day since 1-Jan-0001 A.D X$! (can be used as input to GREGOR) X$! X$ Year =F$Integer(F$CVTime(P1,,"Year")) X$ Month=F$Integer(F$CVTime(P1,,"Month")) X$ Day =F$Integer(F$CVTime(P1,,"Day")) X$! X$! detect leap year X$ Leap=Year-Year/400*400.eq.0 .or. - X Year-Year/100*100.ne.0 .and. Year-Year/4*4.eq.0 X$! X$! Calculate this year's Julian Day X$ 'P2==F$Integer(F$Element(Month-1,",",M2))+Day X$ If Month.gt.2 .and. Leap then 'P2=='P2+1 X$! X$! Calculate the Absolute Julian Day X$ Year=Year-1 X$ 'P3==Year*365+Year/4-Year/100+Year/400+'P2 X$ EndSubroutine X$Gregor: Subroutine X$ On Warning then Exit X$! Converts Julian Day into Gregorian Date X$! Although this routine is not required in this context, I thought I'd X$! include it anyway. X$! Input: X$! P1 = AJDay = Julian Day since 1-Jan-0001 A.D. (as obtained from JULIAN) X$! X$! Output: X$! P2 = Date in absolute format (dd-MON-yyyy) X$ M1=" 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31" X$ M3="Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec" X$! X$ i=P1 X$ im=i/146097 X$ Year=im*400 X$ i=i-im*146097 X$! X$ im=i/36524 X$ Year=Year+im*100 X$ i=i-im*36524 X$! X$ im=i/1461 X$ Year=Year+im*4 X$ i=i-im*1461 X$! X$ im=(i+364)/365-1 X$ Year=Year+im X$! X$ YJDay=P1-Year*365-Year/4+Year/100-Year/400 X$ Year=Year+1 X$! X$ Leap=Year-Year/400*400.eq.0 .or. - X Year-Year/100*100.ne.0 .and. Year-Year/4*4.eq.0 X$! X$ If Leap .and. YJDay.gt.59 then M1[5,2]:="29" X$ n1=0 X$ Month=0 X$Loop: X$ Month=Month+1 X$ n2=n1 X$ n1=n1+F$Integer(F$Element(Month-1,",",M1)) X$ If YJDay.le.n1 then goto Done X$ If Month.lt.12 then goto Loop X$Done: X$ Day=YJDay-n2 X$ Month=F$Element(Month-1,",",M3) X$ 'P2==F$CVTime("''Day'-''Month'-''Year'","Absolute","Date") X$ EndSubroutine $ GoSub Convert_File $ Exit
d2b@rayssd.RAY.COM (Donald A. Borsay) (08/21/87)
In article <870805075119.03q@VLSI.JPL.NASA.GOV> xrjjm%scint.span@VLSI.JPL.NASA.GOV (John McMahon writes: > >Lately I have been playing with the various F$xTIME commands that DCL >offers and I have noticed a couple of things that either are shortcomings, >or more likely things I have missed somewhere. ... >My second time question is, how does one calculate a delta time between two >dates (also in DCL). I am primarily concerned with the number of days >between two dates, but knowing how to figure it out to the second would be >nice. Ok, John and other Netlanders, here's a program I wipped up to assist me in some benchmark DCL procedures I did a while back. Simply cut at the dotted line and replace all $$ with a tab (I here tabs cause some mailers pain). I know this works with Fortran 4.4 and VMS 4.4. Enjoy!! ---- Don |Raytheon Company, Submarine Signal Division, Portsmouth, RI Borsay |ARPAnet: d2b%rayssd.RAY.COM@a.cs.uiuc.edu |UUCPmail: {allegra, decvax!brunix, linus!raybed2}!rayssd!d2b ----------- CUT HERE ---------- CUT HERE ------- CUT HERE -------------- $$program delta !delta_return = p1 - p2 $$implicit none c************************************************************************* c PROGRAM:$$DELTA c WRITTEN BY:$$Don Borsay c c DELTA takes p1 and p2 are absolute ascii times, and creates the DCL c global symbol delta_return as the delta ascii time difference of c P1 - P2 c************************************************************************* $$integer sys$bintim, !Converts ascii time to binary x$$ sys$asctim, !Converts binary time to ascii x$$ lib$subx, !Subtracts binary of arbitrary length x$$ lib$get_foreign,!Get parameters from foreign command line x$$ index, !Position of substring (p2) in string (p1) x$$ lib$set_symbol !Generate DCL symbol for return value $$integer time_a(2), !Binary form of p1 x$$ time_b(2), !Binary form of p2 x$$ delta_return(2),!Binary form of subtracted result x$$ string_length*2 !Length of string_delta_return $$logical status*4 !Status code returned from system routines $$character string_a*64, !Character form of p1 x$$ string_b*64, !Character form of p2 x$$ string_delta_return*64 !Character form of subtracted result $$integer i $$character*80 line $$status = lib$get_foreign(line) $$if (line.eq.' ') then $$ status = lib$get_foreign(string_a,'Enter 1st absolute time: ') $$ status = lib$get_foreign(string_b,'Enter 2nd absolute time: ') $$else $$ i = index (line,',') $$ string_a = line(1:i-1) $$ string_b = line(i+1:) $$end if $$if (string_a.eq.' '.and.string_b.eq.' ') call exit $$status = sys$bintim(string_a,time_a) $$if (.not.status) x$$ call error('Converting 1st parameter',status) $$status = sys$bintim(string_b,time_b) $$if (.not.status) x$$ call error('Converting 2nd parameter',status) $$status = lib$subx(time_B,time_A,delta_return,2) $$if (.not.status) x$$ call error('Performing p1 - p2',status) $$status = sys$asctim(string_length,string_delta_return, x$$ delta_return,%val(0)) $$if (.not.status) x$$ call error('Generating return ascii time',status) $$status = lib$set_symbol('DELTA_RETURN', x$$ string_delta_return(1:string_length)) $$if (.not.status) x$$ call error('DELTA_RETURN could not be created',status) $$call exit(status) $$end $$subroutine error(message,code) $$integer lib$signal !Signals error, producing error messages $$integer code, !Error message code returned from routines x$$ len !Built in routine to return length of string $$character message*(*) !Error message to be outputted on SYS$OUTPUT $$print 10,message 10$$format(1x,'Error ',a<len(message)>,', reason follows:') $$call lib$signal(%val(code)) $$return $$end -- Don |Raytheon Company, Submarine Signal Division, Portsmouth, RI Borsay |ARPAnet: d2b%rayssd.RAY.COM@a.cs.uiuc.edu |UUCPmail: {allegra, decvax!brunix, linus!raybed2}!rayssd!d2b