Data Sources#

Psana1 Data Sources#

The following Data Source classes are compatible with the Psana1EventSource event source.

Psana1Timestamp#

This Data Source class retrieves timestamp information from a psana1 data event.

  • The timestamp information is returned as a numpy array of type float64. The array encodes the timestamp in epoch format as a string of the form <seconds>.<nanoseconds>.

Configuration Parameters for Psana1Timestamp#

This Data Source does not require any configuration parameters beyond the mandatory type entry.

Psana1DetectorInterface#

This Data Source class provides a generic interface for retrieving data from any detector or EPICS process variable stored in a psana1 data event. It accesses the detector or variable via the psana1 Detector interface and supports using attribute names and callable methods to retrieve the desired data.

  • The retrieved data is returned as a numpy array. The default type is float64 unless overridden via the dtype configuration parameter.

  • If the psana_name contains a colon (:) and psana_fields is not specified, the data source is treated as an EPICS process variable (PV) and its current value is retrieved directly.

  • If the psana_name refers to a detector whose psana_fields value is eventCodes, the returned array is always a 1D integer array of size 256. The EVR codes associated with the event are stored at the beginning of the array; any remaining space is filled with the integer value 0.

Configuration Parameters for Psana1DetectorInterface#

  • psana_name (str): The name or alias of the detector or EPICS variable in the psana1 framework. Example: Jungfrau1M

  • psana_fields (str or list of str): This parameter is optional when psana_name contains a colon (PV access). Otherwise it is required. It specifies the dot-separated chain of psana1 detector attributes and/or callable methods used to retrieve the data. If a list is provided, each element is retrieved independently and the results are stacked into a single array. Example: calib or ["calib", "raw"]

  • dtype (str): This parameter is optional. It specifies the numpy dtype of the returned array. The default value is float64. Example: int32

Psana2 Data Sources#

The following Data Source classes are compatible with the Psana2EventSource event source.

Psana2Timestamp#

This Data Source class retrieves timestamp information from a psana2 data event.

  • The timestamp information is returned as a 1D numpy array of type float64.

Configuration Parameters for Psana2Timestamp#

This Data Source does not require any configuration parameters beyond the mandatory type entry.

Psana2DetectorInterface#

This Data Source class provides a generic interface for retrieving data from any detector or EPICS process variable stored in a psana2 data event. It accesses the detector or variable via the psana2 run.Detector interface and supports using attribute names and callable methods to retrieve the desired data.

  • The retrieved data is returned as a numpy array. The default type is float64 unless overridden via the dtype configuration parameter.

  • If the psana_name contains a colon (:) and psana_fields is not specified, the data source is treated as a process variable and its current value is retrieved directly.

Configuration Parameters for Psana2DetectorInterface#

  • psana_name (str): The name or alias of the detector or process variable in the psana2 framework. Example: epicsinfo

  • psana_fields (str or list of str): This parameter is optional when psana_name contains a colon (PV access). Otherwise it is required. It specifies the dot-separated chain of psana2 detector attributes and/or callable methods used to retrieve the data. If a list is provided, each element is retrieved independently and the results are stacked into a single array. Example: raw.calib

  • dtype (str): This parameter is optional. It specifies the numpy dtype of the returned array. The default value is float64. Example: float32

Psana2RunInfo#

This Data Source class retrieves run-level metadata from a psana2 data run. It returns information that is constant across all events in a run,.

  • The metadata is returned as a 1D numpy array of type str containing four elements, in order: the experiment name, the run start timestamp, the run number, and the source identifier string.

Configuration Parameters for Psana2RunInfo#

This Data Source does not require any configuration parameters beyond the mandatory type entry.

Generic Data Sources#

The following Data Source classes are not tied to any specific data-acquisition framework and can be used with any compatible Event Source.

GenericRandomNumpyArray#

This Data Source class generates a random numerical array of a size and type chosen by the user. It is primarily intended for testing and development.

  • The generated array has a shape and dtype defined by the configuration parameters. Integer arrays are filled with random integers uniformly sampled from [0, 255]. Floating-point arrays are filled with random values uniformly sampled from [0, 1).

Configuration Parameters for GenericRandomNumpyArray#

  • array_shape (str): The shape of the generated array, expressed as a comma-separated list of integers following the same convention as numpy’s shape attribute. Example: 512, 512

  • array_dtype (str): The numerical type of the generated array, in the same format as numpy dtype strings. Only integer and floating-point types are supported. Example: float32

FloatValue#

This Data Source class returns a fixed floating-point scalar value defined in the configuration file.

  • The value is returned as a 0-dimensional numpy array of type float64.

Configuration Parameters for FloatValue#

  • value (float): The scalar floating-point value to be returned by this data source on every event. Example: 3.14

IntValue#

This Data Source class returns a fixed integer scalar value defined in the configuration file.

  • The value is returned as a 0-dimensional numpy array of type int.

Configuration Parameters for IntValue#

  • value (int): The scalar integer value to be returned by this data source on every event. Example: 42

SourceIdentifier#

This Data Source class returns the source_identifier string that was provided in the top-level LCLStreamer configuration. It is useful for embedding provenance information into the serialized data.

  • The source identifier is returned as a 0-dimensional numpy array of type str.

Configuration Parameters for SourceIdentifier#

This Data Source does not require any configuration parameters beyond the mandatory type entry.