Siddharth Manay Chandrika Kamath Center for Applied Scientific Computing 2 March 2005 Progress Report on Data Analysis Work at LLNL: Aug’04 - Feb’05 http://www.llnl.gov/casc/sapphire/ UCRL-PRES-209947-DRAFT This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.
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Siddharth Manay Chandrika Kamath Center for Applied Scientific Computing 2 March 2005 Progress Report on Data Analysis Work at LLNL: Aug’04 - Feb’05
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Siddharth ManayChandrika Kamath
Center for Applied Scientific Computing
2 March 2005
Progress Report on Data Analysis Work at LLNL: Aug’04 - Feb’05
http://www.llnl.gov/casc/sapphire/
UCRL-PRES-209947-DRAFT This work was performed under the auspices of the U.S. Department of Energy by
University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.
Sapphire/SDM AHM/SM 2CASC
Our progress on earlier applications
Feature selection for EHOs (data from DIII-D)— IDL code + instructions transferred to Keith@GAT— visit to GAT + talk— interest in licensing Sapphire software— sample scenario ready for the web
Separation of signals in climate data— a standalone C++ code available which uses our
libraries for PCA/ICA— to be used in illustrating creation of workflows— sample scenario ready for the web
Work done by Erick Cantu-Paz, Imola K. Fodor, Abel Gezahegne, Nu Ai Tang
Sapphire/SDM AHM/SM 3CASC
New application: tracking in NSTX data
Joint work with PPPL (Klasky) Problem: track the plasma over time IDL code implementing a variant of
block matching is too slow Prototyping other block-matching
approaches
National SphericalTorus Experiment
Leveraging LDRD funding (CK); work done by Erick Cantu-Paz, Cyrus Harrison
Sapphire/SDM AHM/SM 4CASC
Joint work with PPPL (Klasky, Pomphrey, Monticello)
Classify each of the nodes: quasiperiodic, islands, separatrix
Connections between the nodes Want accurate and robust
classification, valid when few points in each node
New application: classification of puncture (Poincaré) plots for NCSX
National Compact Stellarator Experiment
Quasiperiodic Islands Separatrix
Piecewise Polynomial Models for Classification of Puncture Plots
Sapphire/SDM AHM/SM 6CASC
Polar Coordinates
Transform the (x,y) data to Polar coordinates (r,). Advantages of polar coordinates:
—Radial exaggeration reveals some features that are hard to see otherwise.
—Automatically restricts analysis to radial band with data, ignoring inside and outside.
—Easy to handle rotational invariance.
Sapphire/SDM AHM/SM 7CASC
Piecewise Polynomial Fitting: Dividing data into intervals.
Use the -histograms to find intervals. Need to divide the domain into intervals that are:
—Restricted to regions of that have data.—Small enough so that polynomial will fit the data.—Large enough to span gaps where data is missing
The number of polynomials needed to fit the data and the number of gaps gives the information needed to classify the node:
Number of polynomials
Gaps one two
ZeroQuasiperiodic
Separatrix
> Zero Islands
2 Polynomials2 Gaps Islands
2 Polynomials0 Gaps Separatrix
Sapphire/SDM AHM/SM 10CASC
Results
3995 points, Separatrix 250 points, 3 Islands
Puncture 1, node 79
Zoom around =1.6 Zoom around =1.6
Sapphire/SDM AHM/SM 17CASC
Future work
Set up web pages for climate and fusion scenarios NSTX data: continue building and testing block-
matching algorithms NCSX data
— continue interactions with Neil, Don, Scott — continue to refine and validate approach— investigate ways of making it more robust— investigate exploiting nearby nodes— design and implement in C++ for insertion into