How to Make a Private MDSplus Tree

• pick a nice name for your tree: 'mytesttree'

• define the environment variable for your tree

      [yourname@sunfire]$ export mytesttree_path=/u/yourname/testtreedir
      (the directory can be anything you have write access to )
   

• create the directory (if it doesn't already exist)

      mkdir testtreedir
   

• create a "model tree":

     
      [yourname@sunfire]$ mdstcl
      TCL> edit/new mytesttree
      
      that's it!  now start filling the tree with nodes.
   

  To find an existing model tree from which to start, see How to find the files of an MDSplus Tree

• Create nodes in your new tree using the TRAVERSER app (or TCL commands)

      
      [yourname@sunfire] module load/nstx mdsplus  (this is probably done when you log in)
  
      [yourname@sunfire] traverser -tree mytesttree -shot -1 -edit
      (shot -1 is the model tree)
      
      In Traverser, select "TOP" with the mouse, 
      then select Edit...Add Node...Signal. 
      
      Enter a Node Name, say 'onedim'. 
      
      Quit Traverser while saving the tree.
  

• Copy the model tree to another shot number, say to the number 10:

  Note that the "shot" number is actually just an ID number and need not be related to an actual shot. In fact, ID numbers for TRANSP runs are NOT shot numbers (there is a database that relates shots and ID numbers).

      
      [yourname@sunfire] tcl
      TCL> set tree mytesttree
      TCL> create pulse 10
      TCL> exit
   

• Write to your signal

      
      [yourname@sunfire] idl
      IDL> MDSOPEN, 'mytesttree', 10
      IDL> x = FINDGEN(10)  &  data = x ^2
      IDL> mdsput,':onedim','build_signal($,*,$)',data, x
   

• Read it back

      
      [yourname@sunfire] idl
      IDL> MDSOPEN, 'mytesttree', 10
      IDL> print, MDSVALUE(':onedim')
   

  You can also examine the signal's contents in Traverser.

Comments can be mailed to

updated: 04-Dec-2008
by: Gretchen Zimmer