draw

Draws the given graphical objects.

Prototype

	procedure draw (
		objects  : graphic   
	)

Arguments

An array of any dimensionality of plot objects.

Description

The draw procedure draws each object in the input array, where each object must be a View object. View objects are created by using one of the many gsn functions, or by calling the NCL create language construct.

If any of the ids in objects are invalid, an error message will be displayed.

See Also

NhlDraw, frame, NhlChangeWorkstation

Examples

Example 1

This example uses GSN functions to draw an XY plot with some text strings:

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)

;
; Set up resource list. Turn off the automatic frame advance so we can
; draw some text before the frame is advanced.
;
; We are also turning off the automatic draw, although this is
; not really necessary. This may sometimes be necessary if you need
; to control the draw order of various plot objects.
;
  res          = True
  res@gsnFrame = False
  res@gsnDraw  = False

;
; Create XY plot. Plot will not be drawn nor will the frame be
; advanced (yet).
;
  xy = gsn_xy(wks,x,y,res)

;
; Set up text resource list.
;
  txres               = True
  txres@txFont        = 22
  txres@txFontHeightF = 0.03

;
; Draw a couple of text strings.
;
  gsn_text_ndc(wks,"This is a string at the top",0.5,0.9,txres)
  gsn_text_ndc(wks,"This is a string at the bottom",0.5,0.1,txres)

;
; Now draw the plot and advance the frame.
;
  draw(xy)
  frame(wks)
end

Example 2

This example is the same as example 1, except it's done using the object-oriented interface to NCL's graphics:

begin
;
; Create workstation.
;
  wks = create "poly" xWorkstationClass defaultapp end create

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

  dataid = create "data" coordArraysClass noparent
    "caYArray" : y
  end create

  xy = create "xy" xyPlotClass wks
    "xyCoordData" : dataid
  end create

  text1 = create "text1" textItemClass wks
    "txString"      : "This is a string at the top" 
    "txPosYF"       : 0.5
    "txPosYF"       : 0.9
    "txFontHeightF" : 0.03
  end create

  text2 = create "text1" textItemClass wks
    "txString"      : "This is a string at the bottom"
    "txFont"        : 22
    "txPosXF"       : 0.5
    "txPosYF"       : 0.1
    "txFontHeightF" : 0.03
  end create

  draw((/xy,text1,text2/))
  frame(wks)
end