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NhlIsApp

Returns True for each given object that is an App object.

Prototype

	function NhlIsApp (
		objects  : graphic   
	)

	return_val [dimsizes(objects)] :  logical

Arguments

objects

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.

Description

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

When you use the gsn_open_wks function to create a workstation, an App object is created internally and attached to the returned workstation id as an attribute called "app". You can also retrieve the default App class that NCL creates internally by calling the NhlAppGetDefaultParentId function.

See Also

NhlAppGetDefaultParentId, NhlIsDataComm, NhlIsDataItem, NhlIsDataSpec, NhlIsTransform, NhlIsView, NhlIsWorkstation

Examples

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"

begin
;
; 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

  print(NhlIsApp((/wks,wks@app,xy,text/)))   ; Should be (/False,True,False,False/)