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Returns True for each given object that is a DataItem object.


	function NhlIsDataItem (
		objects  : graphic   

	return_val [dimsizes(objects)] :  logical



An array of one or more instances of NCL objects. NCL objects are created by using one of the many gsn functions, or by calling the NCL create language construct.

Return value

This function returns a logical array with the same dimensions as the input argument objects.


For each object identifier in the objects array, the value True is returned if the object is a DataItem object, and False otherwise. If any of the input values is an invalid object, then a missing value is returned for that element.

DataItem objects are objects used to represent data, like ScalarField and VectorField objects. When you use one of the gsn plotting functions, like gsn_contour, gsn_csm_xy, or gsn_csm_vector_map, the DataItem object that is created internally is returned as an attribute of the return variable called "data".

See Also

NhlIsApp, NhlIsDataComm, NhlIsDataSpec, NhlIsTransform, NhlIsView, NhlIsWorkstation


Example 1

This example creates various NCL objects using both gsn functions, and by calling the NCL create language construct to create a text string.

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"

; Create workstation.
  wks = gsn_open_wks("x11","test")

; Create a data object.
  npts = 500
  x    = fspan(0,npts-1,npts)
  y    = 500.+ 0.9 * x * sin(0.031415926535898*x)
  xy   = gsn_xy(wks,x,y,False)

; Use the "create" construct to create a text string.
 text = create "text1" textItemClass wks
    "txString"      : "This is a string"
    "txPosYF"       : 0.5
    "txPosYF"       : 0.9
  end create

  map = gsn_map(wks,"LambertConformal",False)

  print(NhlIsDataItem((/xy,xy@data,xy@dataspec,map,text/)))   ; Should be (/False,True,False,False,False/)