Introductory Notes

From Robert Underwood at Compression Workshop on Feb. 15, 2024

Performance

A document that shows SZ performance with LCLS crystallographic data (relative error bounds) is here.  It does not have results for the absolute-error-bound case, which we think is more relevant for LCLS-II, but Chuck Yoon has studied that for crystallography data (see JIRA tickets).

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Increasing the compression factor to 17 ((maximum absolute error  =200, SZ3 compression) does appear to degrade the final result (figures not included). 

Some results from Ric Claus running this compression algorithm in the DAQ system are here: EpixHR Emulator.

analysis:

Low Intensity SAXS/WAXS Compression Results

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Code for analysis with compression is in a fork of small data tools, and jupyter notebook, plus the "reduce scattering code" (in https://github.com/Solution-Phase-Chemistry/ReduceScatt 

cuSZ Performance

Courtesy of Jiannan Tian.  Status of behavior/performance of cuSZ on 4/28/24 (a work-in-progress).

Running Stefano's Code

On old psana system:

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python batch_jobs.py  --exp xpplz0620 --runs 'range(249, 251)' --abserrors '[0, 100, 120]' --pretransforms '[0]' --forreal 01

(Step2) (3 minutes) (run the above "non-compressed" notebook xpp_example_249_50.ipynb on the generated h5 file using use ana-4.0.50-py3 environment to generate the above plot.   saves the middle "uncompressed" figure above.

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