Github user andrewor14 commented on a diff in the pull request:
https://github.com/apache/spark/pull/139#discussion_r10616840
--- Diff: python/pyspark/rdd.py ---
@@ -566,8 +566,32 @@ def func(iterator):
vals = self.mapPartitions(func).collect()
return reduce(op, vals, zeroValue)
- # TODO: aggregate
+ def aggregate(self, zeroValue, seqOp, combOp):
+ """
+ Aggregate the elements of each partition, and then the results for
all
+ the partitions, using a given combine functions and a neutral "zero
+ value."
+
+ The functions C{op(t1, t2)} is allowed to modify C{t1} and return
it
+ as its result value to avoid object allocation; however, it should
not
+ modify C{t2}.
+
+ The first function (seqOp) can return a different result type, U,
than
+ the type of this RDD. Thus, we need one operation for merging a T
into an U
+ and one operation for merging two U
+ >>> seqOp = (lambda x, y: (x[0]+y, x[1] + 1))
+ >>> combOp = (lambda x, y: (x[0]+y[0], x[1] + y[1]))
--- End diff --
nit: spacing around `+` is inconsistent
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
