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NOTE: In python, if you want to exit early you often use a "break" statement. When running psana-python with mpi parallelization, however, not all cores will see this statement, and the result will be that your job will hang at the end. To avoid this use the "max_events" keyword argument to DataSource. For example: "DataSource(exp='tmoc00118',run=123,max_events=10)".
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from psana import DataSource
import numpy as np
# called back on each SRV node, for every smd.event() call below
def test_callback(data_dict):
print(data_dict)
ds = DataSource(exp='tmoc00118', run=123)
# batch_size here specifies how often the dictionary of information
# is sent to the SRV nodes
smd = ds.smalldata(filename='my.h5', batch_size=5, callbacks=[test_callback])
run = next(ds.runs())
# necessary (instead of "None") since some ranks may not receive events
# and the smd.sum() below could fail
arrsum = np.zeros((2), dtype=np.int)
for i,evt in enumerate(run.events()):
myones = np.ones_like(arrsum)
smd.event(evt, myfloat=2.0, arrint=myones)
arrsum += myones
if smd.summary:
smd.sum(arrsum)
smd.save_summary({'summary_array' : arrsum}, summary_int=1)
smd.done() |
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