skewt

Hello:

In the description of skewt, it shows:
Example: Let skewT be the returned object. The data mat be retrieved via:
   cape = skewT@Cape
   pwat = skewT@Pwat

I wrote the following in my script as:
;...............
  skewt_bkgd = skewT_BackGround (wks, skewtOpts)
  skewt_data = skewT_PlotData (wks, skewt_bkgd, pp,tt,tc,h \
                                    , wsp,dir, dataOpts)
  draw (skewt_bkgd)
  draw (skewt_data)
  frame(wks)
print(skewt_data@Cape)
;.........................

However, when I run it, I got the following information:
warning:Attempt to reference attribute (Cape) which is undefined
(0) -999

But the CAPE value was shown in the diagram generated by my script.

Can you tell me what is wrong? I use NCL
 Copyright (C) 1995-2010 - All Rights Reserved
 University Corporation for Atmospheric Research
 NCAR Command Language Version 5.2.0
 The use of this software is governed by a License Agreement.
 See http://www.ncl.ucar.edu/ for more details.

Thank you very much!

Ed
_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Sun Feb 26 18:15:16 2012