cf.set_performance(chunksize=None, free_memory_factor=None)[source]

Tune performance of parallelisation by setting chunksize and free memory factor. By just providing the chunksize it can be changed to a smaller value than an upper limit, which is determined by the existing free memory factor. If just the free memory factor is provided then the chunksize is set to the corresponding upper limit. Note that the free memory factor is the fraction of memory kept free as a temporary workspace and must be a sensible value between zero and one. If both arguments are provided then the free memory factor is changed first and then the chunksize is set provided it is consistent with the new free memory value. If any of the arguments is invalid then an error is raised and no parameters are changed. When called with no arguments the existing values of the parameters are returned in a tuple.

chunksize: float, optional

The size in bytes of a chunk used by LAMA to partition the data array.

free_memory_factor: float, optional

The fraction of memory to keep free as a temporary workspace.


A tuple of the previous chunksize and free_memory_factor.