1. Data Optimization for Reflectometer Simulation Marc Osherson Science Education Summer Intern 9/1/2005

2. FWR  A 2D simulation of a full wave reflectometer for which Eliot Feibush has been developing a GUI.  Client-server architecture.  GUI can run on a user’s laptop.  Input and Output netCDF files are on the PPPL cluster.  Files had to be transferred to the laptop, and processed there.

3. PPPL Compute Cluster User’s PC, Mac, Linux Multi – Tier Software Architecture Java Client GUI Java Servlet FWR Simulation TRANSP genxpl trxpl netCDF Files MDSplus Server TRANSP Runs Correlation Graphs FWR Input FWR Solution netCDFcon

4. Problem  Input and output files became prohibitively large for laptops, e.g. 100MB output files.  The files would take too long to transfer and process.  The Java heap memory was too small and could not handle such files.

5. Approach  Server side post-processing of input and output files.  Reduce simulation data to just the displayable image data.  Arrays of doubles converted to byte data.  Provide a means for recovering the actual data values.

6. netCDFcon (C program)  Converts the plasma input file into efficient image data.  Computes the three cutoff images and scales them into image data.  Converts the full wave solution file to image data.  Runs on the PPPL compute server, much faster than running Java on a laptop.  Roughly 100:1 speed up.  Converts a 100MB solution file to 1MB.  Significantly reduces file transfer time.  Convert once, display many times.

7. netCDFcon  Linux command line program.  Command line arguments:  Input file  Output file  Type of processing  List of variables, e.g. ne te bb  Run by the servlet in a script file.

8. FWR Screenshots

9. Reflectometer Simulation

10. FWR Demo

11. Questions ?

12. Thank you  To the entire science education staff for making this possible.  To Eliot Feibush for all the help he’s given me.  To PPPL for this opportunity.