...

• many of the "building block" tools can be used at FELs around the world: e.g. python, MPI and scikit-beam algorithms
• part of the world-standard conda python ecosystem
• same code works for online/offline analysis analysis (with real-time plot display), allowing users to do their entire analysis chain with one tool
• ability to use both simple and complex languages (python/C++)
• users don't have to wait for xtc-to-hdf5 conversion time
• access to calibrated images both online/offline (pedestals, common-mode, geometry, bad-pixel mask) for complex detectors (CSPAD, pnCCD, EPIX)
• local support at SLAC from ~10 people (core offline group and instrument engineers)
• simple detector names using experiment-specific "aliases"
• free
• ability to randomly access xtc data ("jump" to event in middle of file)
• support for fast parallel processing of xtc files with hundreds of cores using MPI
• ability to run entire psana code on Windows/Mac machines using virtual box (useful for off-site visualization or code development, for example)
  

Legacy versions of psana

The command above:

source /reg/g/psdm/etc/psconda.sh

Activates the latest version of psana. However, it might still be useful, for compatibility with existing code, to run a legacy version of psana. After running the command above, the complete list of available psana versions can be displayed using the following command:

conda info --envs

To run a legacy version of psana, the current psana environment needs to be deactivated. The required version of psana can then be launched. For example, if version 4.0.23 is required, it can be accessed with the following sequence of commands

conda deactivate
conda activate ana-4.0.23

Please be aware that legacy versions of psana, while keeping compatibility with existing software, cannot of course take advantage of features and improvement introduced in more recent versions of the environment.