You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@spark.apache.org by Sherd Fox <sh...@gmail.com> on 2022/01/21 09:25:30 UTC
questions on these functions
Hello sparkers,
What were the differences for leftFold, rightFold and the fold in RDD
functions?
I am not very clear about the usage of them.
Thanks.
Re: questions on these functions
Posted by Sean Owen <sr...@gmail.com>.
Eh, are you talking about foldLeft and foldRight in Scala? those are not
from Hadoop or Spark.
They are common functions in functional languages. They 'fold' a value into
a new value by apply a function to the starting value and every element of
a collection.
Because the op may be non-commutative, doing this left to right or right to
left is different, hence two functions.
On Fri, Jan 21, 2022 at 6:59 AM Theodore J Griesenbrock <te...@ibm.com>
wrote:
> I discovered several instances of discussion on leftFold and rightFold in
> a variety of forums, but I can not find anything related to RDD in the
> official documentation:
>
>
> https://spark.apache.org/docs/latest/api/scala/org/apache/spark/rdd/RDD.html
>
> It appears to be non-related to Spark, and probably something
> Hadoop-related. Can you please be more specific on how leftFold and
> rightFold is imported and the language you are using to implement Spark?
>
> Thanks!
>
> -T.J.
>
>
> *T.J. Griesenbrock*
> Technical Release Manager
> Watson Health
> He/Him/His
>
> +1 (602) 377-7673 (Text only)
> teej@ibm.com
>
> IBM
>
>
>
> ----- Original message -----
> From: "Sherd Fox" <sh...@gmail.com>
> To: user@spark.apache.org
> Cc:
> Subject: [EXTERNAL] questions on these functions
> Date: Fri, Jan 21, 2022 04:26
>
> Hello sparkers,
>
> What were the differences for leftFold, rightFold and the fold in RDD
> functions?
>
> I am not very clear about the usage of them.
>
> Thanks.
>
>
>
>
> --------------------------------------------------------------------- To
> unsubscribe e-mail: user-unsubscribe@spark.apache.org
Re: questions on these functions
Posted by Sherd Fox <sh...@gmail.com>.
sorry I am programming with scala who has these functions.
regards.
On Fri, 21 Jan 2022 at 20:59, Theodore J Griesenbrock <te...@ibm.com> wrote:
> I discovered several instances of discussion on leftFold and rightFold in
> a variety of forums, but I can not find anything related to RDD in the
> official documentation:
>
>
> https://spark.apache.org/docs/latest/api/scala/org/apache/spark/rdd/RDD.html
>
> It appears to be non-related to Spark, and probably something
> Hadoop-related. Can you please be more specific on how leftFold and
> rightFold is imported and the language you are using to implement Spark?
>
> Thanks!
>
> -T.J.
>
>
> *T.J. Griesenbrock*
> Technical Release Manager
> Watson Health
> He/Him/His
>
> +1 (602) 377-7673 (Text only)
> teej@ibm.com
>
> IBM
>
>
>
> ----- Original message -----
> From: "Sherd Fox" <sh...@gmail.com>
> To: user@spark.apache.org
> Cc:
> Subject: [EXTERNAL] questions on these functions
> Date: Fri, Jan 21, 2022 04:26
>
> Hello sparkers,
>
> What were the differences for leftFold, rightFold and the fold in RDD
> functions?
>
> I am not very clear about the usage of them.
>
> Thanks.
>
>
>
>
>
Re: questions on these functions
Posted by Theodore J Griesenbrock <te...@ibm.com>.
I discovered several instances of discussion on leftFold and rightFold in a
variety of forums, but I can not find anything related to RDD in the official
documentation:
<https://spark.apache.org/docs/latest/api/scala/org/apache/spark/rdd/RDD.html>
It appears to be non-related to Spark, and probably something Hadoop-related.
Can you please be more specific on how leftFold and rightFold is imported and
the language you are using to implement Spark?
Thanks!
-T.J.
**T.J. Griesenbrock**
Technical Release Manager
Watson Health
He/Him/His
+1 (602) 377-7673 (Text only)
teej@ibm.com
IBM
> \----- Original message -----
> From: "Sherd Fox" <sh...@gmail.com>
> To: user@spark.apache.org
> Cc:
> Subject: [EXTERNAL] questions on these functions
> Date: Fri, Jan 21, 2022 04:26
>
>
>
> Hello sparkers,
>
>
>
> What were the differences for leftFold, rightFold and the fold in RDD
> functions?
>
>
>
> I am not very clear about the usage of them.
>
>
>
> Thanks.
\--------------------------------------------------------------------- To
unsubscribe e-mail: user-unsubscribe@spark.apache.org