[Plplot-cvs] SF.net SVN: plplot:[9480] trunk/lib/qsastime

[<ai...@us...>]

Revision: 9480
          http://plplot.svn.sourceforge.net/plplot/?rev=9480&view=rev
Author:   airwin
Date:     2009-02-09 21:01:38 +0000 (Mon, 09 Feb 2009)

Log Message:
-----------
AWI for Tony Allen.  Fix bugs in negative years and negative Julian dates
for breakDownMJD and associated helper and extra functions.

Modified Paths:
--------------
    trunk/lib/qsastime/qsastime.c
    trunk/lib/qsastime/qsastime_extra.c

Modified: trunk/lib/qsastime/qsastime.c
===================================================================
--- trunk/lib/qsastime/qsastime.c	2009-02-09 10:47:34 UTC (rev 9479)
+++ trunk/lib/qsastime/qsastime.c	2009-02-09 21:01:38 UTC (rev 9480)
@@ -79,6 +79,7 @@
     year100 = year - 1;
     year400 = year - 1;
   }  
+  
   if((forceJulian == 0 && (year < 1582 || (year == 1582 && month < 9) || (year == 1582 && month == 9 && day < 15))) || forceJulian == 1)
     {
       /* count leap years on proleptic Julian Calendar */
@@ -147,6 +148,7 @@
 {
   static char *dow = {"Wed\0Thu\0Fri\0Sat\0Sun\0Mon\0Tue"};
   int d = MJD->base_day % 7;
+  if(d < 0) d += 7;
   return &(dow[d*4]);
 }
 
@@ -154,6 +156,7 @@
 {
   static char *dow = {"Wednesday\0Thursday\0\0Friday\0\0\0\0Saturday\0\0Sunday\0\0\0\0Monday\0\0\0\0Tuesday"};
   int d = MJD->base_day % 7;
+  if(d < 0) d += 7;
   return &(dow[d*10]);
 }
 
@@ -190,33 +193,37 @@
 
   j = MJD->base_day + extra_days;
 	
-  if( j <= -678943) {
+	if( j < -678943) {
 	
-    /* BCE dates */
+		/* Negative CE dates */
 
-    j += 678943;
-    if( j > 0)
-      {
-	/* must be in year BCE 1 (CE year 0) */
-	year = 0;
-	/* subtract nothing from j */
-      }
-    else
-      {
-	/* negative years */
-	year = (int) ((float)j / 365.25) -1;
-	doy = j - (int)(year  * 365.25);
-      }
+		j += 678943; 
 		
-  }
+		/* negative years */
+		year = (int) ((float)(j-365) / 365.25);
+		doy = j +1 - year * 365.25;
+				
+	}
+	else if( j < -678577) {
+	
+		/* CE = 0, BCE = 1 dates */
+
+		j += 678943; 
+		
+		/* negative years */
+		year = 0;
+		doy = j +1;
+		
+	}
   else if( j < -100840 || forceJulian == 1)
     {
       /* Julian Dates */
       j += 678943;
 		
       year = (int) ((float)j / 365.25);
-	
-      doy = j - (int)(year * 365.25);
+	  lastyear = year - 1;
+	  doy = j - year * 365 - lastyear / 4;
+
 		
     }
   else
@@ -255,23 +262,22 @@
 
   j = MJD->base_day + extra_days;
 	
-  if( j <= -678943) {
+  if( j <= -678577) {
 	
     /* BCE dates */
 
     j += 678943;
-    if( j > 0)
-      {
-	/* must be in year BCE 1 (CE year 0) */
-	*year = 0;
-	/* subtract nothing from j */
-      }
-    else
-      {
-	/* negative years */
-	*year = (int) ((float)j / 365.25) -1;
-	j = j - (int)((*year)  * 365.25);
-      }
+	if( j>=0) 
+	{
+		*year = 0;
+		j++;
+	}
+	else
+	{
+		/* negative years */
+		*year = (int) ((float)(j-365) / 365.25);
+		j = j +1 - *year * 365.25;
+	}
 		
     /* j is now always positive */
     *month = -1;
@@ -287,8 +293,6 @@
       }
     else
       {
-	/* put this year's leap day back as it is done here */
-	j++;
 	while(j > MonthStartDOY_L[*month +1])
 	  {
 	    (*month)++;
@@ -304,7 +308,8 @@
 		
       *year = (int) ((float)j / 365.25);
 	
-      j = j - (int)(*year * 365.25);
+		lastyear = *year - 1;
+		 j = j - *year * 365 - lastyear / 4;
 		
       *month = -1;
       if(*year%4 != 0)
@@ -318,8 +323,6 @@
 	}
       else
 	{
-	  /* put leap day back for this year as done here */
-	  j++;
 	  while(j > MonthStartDOY_L[*month + 1])
 	    {
 	      (*month)++;

Modified: trunk/lib/qsastime/qsastime_extra.c
===================================================================
--- trunk/lib/qsastime/qsastime_extra.c	2009-02-09 10:47:34 UTC (rev 9479)
+++ trunk/lib/qsastime/qsastime_extra.c	2009-02-09 21:01:38 UTC (rev 9480)
@@ -55,6 +55,7 @@
   /* parse off year */
 
   y = strtol(&(ISOstring[startAt]), NULL, 10);
+  if(ISOstring[startAt] == '-' || ISOstring[startAt] == '+') startAt++;
   startAt += 5;
   if(startAt > len) return 1;
 
@@ -100,7 +101,7 @@
       /* MJD for Jan 1 0000 (correctly Jan 01, BCE 1) is  - 678943, count from there */
       /* negative CE (AD) years convert to BCE (BC) as  BCE = 1 - CE, e.g. 2 BCE = -1 CE */
 		
-      leaps = year / 4 - 1 ; /* (note leaps is negative here and year 0 (1 BCE) was a leap year */
+      leaps = (year -4) / 4; /* (note leaps is negative here and year 0 (1 BCE) was a leap year */
       MJD->base_day = year * 365 + leaps + doy - 678943;
 
     }


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