NCL Website header
NCL Home > Documentation > HLUs > API


The Fortran name of this function is NhlFUpdateData.

This function is used to force a DataComm object to update its internal state to any changes that have occurred in associated DataItems.

C synopsis

#include <ncarg/hlu/DataComm.h>

NhlErrorTypes NhlUpdateData(
		int		dcommid

Fortran synopsis

      subroutine NhlFUpdateData(dcommid, ierr)
      integer dcommid, ierr


dcommid (input)
Identifies the DataComm object to update.
ierr (output, Fortran only)
Error code.


Type name:		NhlTErrorTypes
typedef enum _NhlErrType{
	NhlFATAL	= -4,	/* "FATAL"	*/
	NhlWARNING	= -3,	/* "WARNING"	*/
	NhlINFO		= -2,	/* "INFO"	*/
	NhlNOERROR	= -1	/* "NOERROR"	*/
} NhlErrorTypes;


This function is used to force the given DataComm object to update its internal state. This function is only useful if the dcDelayCompute resource of the DataComm object is set to true. Otherwise the DataComm object will already be up to date. It is not really necessary to call this function, since the DataComm object automatically updates itself when the NhlDraw function is called.

The does not get out-of-date when the application programmer makes AddData or RemoveData calls to it. It is only if the application programmer makes a SetValues call to an associated DataItem object that the DataComm object has the possibility of being out-of-date. For example, if the application programmer changed the Minimum value in an associated DataItem object, it is possible the data extents of the plot (DataComm object) may be affected. It is important that the DataComm object respond to these changes in the data.

Return values

The NhlUpdateData C function returns a value of type NhlErrorTypes, and the NhlFUpdateData Fortran subroutine returns the error in ierr. The following table indicates what the return error values mean:
Value	|			Meaning
NOERROR	|	The DataComm object was updated without
	|	any problem. (It may have already been
	|	up-to-date.)
INFO	|	Recoverable error.
WARNING	|	Recoverable error, but there may be more
	|	problems.
FATAL	|	Unable to update the DataComm object.

See also