evaluates expr using automatic parallelization.
Details and Options
- Parallelize[expr] automatically distributes different parts of the evaluation of expr among different available kernels and processors.
- Parallelize[expr] normally gives the same result as evaluating expr, except for side effects during the computation.
- Parallelize has attribute HoldFirst, so that expressions are not evaluated before parallelization.
- The Method option for Parallelize specifies the parallelization method to use. Possible settings include:
"CoarsestGrained" break the computation into as many pieces as there are available kernels "FinestGrained" break the computation into the smallest possible subunits "EvaluationsPerKernel"->e break the computation into at most e pieces per kernel "ItemsPerEvaluation"->m break the computation into evaluations of at most m subunits each Automatic compromise between overhead and load-balancing
- Method->"CoarsestGrained" is suitable for computations involving many subunits, all of which take the same amount of time. It minimizes overhead, but does not provide any load balancing.
- Method->"FinestGrained" is suitable for computations involving few subunits whose evaluations take different amounts of time. It leads to higher overhead, but maximizes load balancing.
- The DistributedContexts option for Parallelize specifies which symbols appearing in expr have their definitions automatically distributed to all available kernels before the computation.
- The default value is DistributedContexts:>$Context, which distributes definitions of all symbols in the current context, but does not distribute definitions of symbols from packages.
Examplesopen allclose all
Basic Examples (3)
Listable Functions (1)
Structure-Preserving Functions (3)
Without a function, Parallelize simply evaluates the elements in parallel:
The argument does not have to be an explicit List:
Inner and Outer Products (2)
Associative Functions (1)
Functions with the attribute Flat automatically parallelize:
Generalizations & Extensions (3)
Restore the value of the DistributedContexts option to its default:
Properties & Relations (7)
Possible Issues (8)
Use DistributeDefinitions to distribute such definitions:
Alternatively, set the DistributedContexts option to include all contexts: