Added gridInqXvalsPart() and gridInqYvalsPart().

ChangeLog

@@ -3,6 +3,10 @@
         * using EXSE library version 1.4.1
 	* Version 1.9.6 released
 
+2018-09-26  Uwe Schulzweida
+
+	* Added gridInqXvalsPart() and gridInqYvalsPart() [patch from: Niklas Rber]
+
 2018-09-17  Uwe Schulzweida
 
 	* Added function cdiInqGridMissval()

src/cdi.h

@@ -760,6 +760,7 @@ void    gridDefXvals(int gridID, const double xvals[]);
 
 /*      gridInqXvals: Get all values of a X-axis */
 size_t  gridInqXvals(int gridID, double xvals[]);
+size_t  gridInqXvalsPart(int gridID, int start, size_t size, double xvals[]);
 
 /*      gridInqXIsc: Find out whether X-coordinate is of type CHAR */
 int     gridInqXIsc(int gridID);
@@ -772,6 +773,7 @@ void    gridDefYvals(int gridID, const double yvals[]);
 
 /*      gridInqYvals: Get all values of a Y-axis */
 size_t  gridInqYvals(int gridID, double yvals[]);
+size_t  gridInqYvalsPart(int gridID, int start, size_t size, double yvals[]);
 
 /*      gridInqYIsc: Find out whether Y-coordinate is of type CHAR */
 int     gridInqYIsc(int gridID);

src/grid.c

@@ -1542,6 +1542,32 @@ size_t gridInqXValsSerial(grid_t *gridptr, double *xvals)
   return size;
 }
 
+static
+size_t gridInqXValsPartSerial(grid_t *gridptr, int start, size_t length, double *xvals)
+{
+  size_t size;
+  if ( gridptr->type == GRID_CURVILINEAR || gridptr->type == GRID_UNSTRUCTURED )
+    size = gridptr->size;
+  else if ( gridptr->type == GRID_GAUSSIAN_REDUCED )
+    size = 2;
+  else
+    size = gridptr->x.size;
+
+  if ( CDI_Debug && size == 0 )
+    Warning("size undefined for gridID = %d", gridptr->self);
+
+  if ( gridptr->x.vals )
+    {
+      if ( size && xvals )
+        {
+          const double *gridptr_xvals = gridptr->vtable->inqXValsPtr(gridptr);
+          memcpy(xvals, gridptr_xvals+start, length * sizeof (double));
+        }
+    }
+  else
+    size = 0;
+}
+
 static
 size_t gridInqXCvalsSerial(grid_t *gridptr, char **xcvals)
 {
@@ -1600,6 +1626,13 @@ size_t gridInqXvals(int gridID, double *xvals)
 }
 
 
+size_t gridInqXvalsPart(int gridID, int start, size_t length, double *xvals)
+{
+  grid_t *gridptr = grid_to_pointer(gridID);
+  return gridptr->vtable->inqXValsPart(gridptr, start, length, xvals);
+}
+
+
 size_t gridInqXCvals(int gridID, char **xcvals)
 {
   grid_t *gridptr = grid_to_pointer(gridID);
@@ -1712,6 +1745,30 @@ size_t gridInqYValsSerial(grid_t *gridptr, double *yvals)
   return size;
 }
 
+static
+size_t gridInqYValsPartSerial(grid_t *gridptr, int start, size_t length, double *yvals)
+{
+  int gridtype = gridptr->type;
+  size_t size = (gridtype == GRID_CURVILINEAR || gridtype == GRID_UNSTRUCTURED)
+            ? gridptr->size : gridptr->y.size;
+
+  if ( CDI_Debug && size == 0 )
+    Warning("size undefined for gridID = %d!", gridptr->self);
+
+  if ( gridptr->y.vals )
+    {
+      if ( size && yvals )
+        {
+          const double *gridptr_yvals = gridptr->vtable->inqYValsPtr(gridptr);
+          memcpy(yvals, gridptr_yvals+start, length * sizeof (double));
+        }
+    }
+  else
+    size = 0;
+
+  return size;
+}
+
 /*
 @Function  gridInqYvals
 @Title     Get all values of a Y-axis
@@ -1739,6 +1796,13 @@ size_t gridInqYvals(int gridID, double *yvals)
 }
 
 
+size_t gridInqYvalsPart(int gridID, int start, size_t size, double *yvals)
+{
+  grid_t *gridptr = grid_to_pointer(gridID);
+  return gridptr->vtable->inqYValsPart(gridptr, start, size, yvals);
+}
+
+
 size_t gridInqYCvals(int gridID, char **ycvals)
 {
   grid_t *gridptr = grid_to_pointer(gridID);
@@ -5057,9 +5121,11 @@ const struct gridVirtTable cdiGridVtable
   .inqXVal = gridInqXValSerial,
   .inqYVal = gridInqYValSerial,
   .inqXVals = gridInqXValsSerial,
+  .inqXValsPart = gridInqXValsPartSerial,
   .inqXCvals = gridInqXCvalsSerial,
   .inqXIsc = gridInqXIscSerial,
   .inqYVals = gridInqYValsSerial,
+  .inqYValsPart = gridInqYValsPartSerial,
   .inqYCvals = gridInqYCvalsSerial,
   .inqYIsc = gridInqYIscSerial,
   .inqXValsPtr = gridInqXValsPtrSerial,

src/grid.h

@@ -31,9 +31,11 @@ struct gridVirtTable
   double (*inqXVal)(grid_t *gridptr, size_t index);
   double (*inqYVal)(grid_t *gridptr, size_t index);
   size_t (*inqXVals)(grid_t *gridptr, double *xvals);
+  size_t (*inqXValsPart)(grid_t *gridptr, int start, size_t length, double *xvals);
   size_t (*inqXCvals)(grid_t *gridptr, char **xcvals);
   int (*inqXIsc)(grid_t *gridptr);
   size_t (*inqYVals)(grid_t *gridptr, double *yvals);
+  size_t (*inqYValsPart)(grid_t *gridptr, int start, size_t length, double *yvals);
   size_t (*inqYCvals)(grid_t *gridptr, char **ycvals);
   int (*inqYIsc)(grid_t *gridptr);
   const double *(*inqXValsPtr)(grid_t *gridptr);