GRIB1 decode: Correct ZeroShiftError of simple packed spherical harmonics

ChangeLog

+2010-07-05 Edi Kirk <E.Kirk@gmx.de>
+
+	* GRIB1 decode: Correct ZeroShiftError of simple packed spherical harmonics
+
 2010-07-01  Uwe Schulzweida  <Uwe.Schulzweida@zmaw.de>
 
 	* cdfInqContents: use complex packing for spectral data [report: Edi Kirk]

src/cgribex.h

@@ -166,6 +166,7 @@
 
 
 
+void  gribFixZSE(int flag);
 void  gribSetDebug(int debug);
 void  gribSetRound(int round);
 void  gribSetRefDP(double refval);

src/cgribexlib.c

 
-/* Automatically generated by m214003 at 2010-06-30, do not edit */
+/* Automatically generated by m214003 at 2010-07-05, do not edit */
 
 /* CGRIBEXLIB_VERSION="1.4.5.1" */
 
@@ -1266,6 +1266,7 @@ gribExSP(int *isec0, int *isec1, int *isec2, float *fsec2sp, int *isec3,
 }
 
 int GRB_Debug    = 0;    /* If set to 1, debugging */
+int GRB_Fix_ZSE  = 0;    /* Fix ZeroShiftError of simple packed spherical harmonics */
 
 void gribSetDebug(int debug)
 {
@@ -1277,6 +1278,16 @@ void gribSetDebug(int debug)
     Message(func, "debug level %d", debug);
 }
 
+void gribFixZSE(int flag)
+{
+  static char func[] = "gribFixZSE";
+
+  GRB_Fix_ZSE = flag;
+
+  if ( GRB_Debug )
+    Message(func, "Fix ZeroShiftError set to %d", flag);
+}
+
 void gribSetRound(int round)
 {
 }
@@ -4526,6 +4537,7 @@ int decodeBDS(int decscale, unsigned char *bds, int *isec2, int *isec4,
   double fmin = 0., zscale = 0.;
   double *fpdata = fsec4;
   int bdsLen;
+  extern int GRB_Fix_ZSE;
 
   *iret = 0;
   igrib = bds;
@@ -4748,6 +4760,16 @@ int decodeBDS(int decscale, unsigned char *bds, int *isec2, int *isec4,
       scaleComplex(fsec4, pcStart, pcScale, ISEC2_PentaJ, 1);
     }
 
+  if ( GRB_Fix_ZSE )  /* Fix ZeroShiftError of simple packed spherical harmonics */
+    if ( lspherc && !lcomplex )
+      {
+        /* 20100705: Fix ZeroShiftError - Edi Kirk */
+	if ( fsec4[1] != 0.0 )
+	  {
+	    double zserr = fsec4[1];
+	    for ( i = 1; i < ISEC4_NumValues; i++ ) fsec4[i] -= zserr;
+	  }
+      }
 
   if ( decscale )
     {
@@ -8854,7 +8876,7 @@ int  gribUnzip(unsigned char *dbuf, long dbufsize, unsigned char *sbuf, long sbu
 
   return (gribLen);
 }
-static const char grb_libvers[] = "1.4.5.1" " of ""Jun 30 2010"" ""10:28:56";
+static const char grb_libvers[] = "1.4.5.1" " of ""Jul  5 2010"" ""09:21:38";
 const char *
 cgribexLibraryVersion(void)
 {

src/stream_int.c

@@ -14,6 +14,9 @@
 #include "cdi.h"
 #include "stream_int.h"
 
+#if  defined  (HAVE_LIBCGRIBEX)
+#include "cgribex.h"
+#endif
 
 int cdiDefaultCalendar = CALENDAR_PROLEPTIC;
 
@@ -110,6 +113,10 @@ void cdiInitialize(void)
     {
       Init_CDI = TRUE;
 
+#if  defined  (HAVE_LIBCGRIBEX)
+      gribFixZSE(1); /* Fix ZeroShiftError of simple packed spherical harmonics */
+#endif
+
       value = cdiGetenvInt("CD_REGULARGRID");
       if ( value >= 0 ) cdiDataUnreduced = (int) value;