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Note the use of the key "do_not_translate:xxx" the :xxx is not necessary, but it helps to uniquely quality the event data, and it will affect the become a part of the 'src' group name where the do_not_translate event data is written to.  Since both std::string and a ndarray<float,1> are types that the Translator knows how to write, it will create the following groups and datasets in the hdf5 file:

• /Configure:0000/Run:0000/Filtered:0000/time  - this is as discussed above
• /Configure:0000/Run:0000/Filtered:0000/std::string/message/data  - this will be a dataset of variable length strings, each entry will be the string "The beam energy is bad"
• /Configure:0000/Run:0000/Filtered:0000/NDArray/measurements/data - this will be a dataset where each entry is a 1D array of 4 floats, with the values 0.4, 1.3, 2.2, 3.1

Filtering from Python Modules

Presently the only types that a Python module can add to the event store which will be seen by C++ modules are ndarrays. A python module will need to add one of the ndarrays that the translator knows about to filter events.

Filtering Types

The psana.cfg file accepts a number of parameters that will filter out sets of psana types.  For example setting

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