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From David Ortiz <dpo5...@gmail.com>
Subject Re: How to count MemPipeline?
Date Wed, 11 Mar 2015 13:44:32 GMT
Kristoffer,

      Based on that code snippet, why not just do:

PCollection<String> lines =
MemPipeline.typedCollectionOf(Writables.strings(), input);
PTable<String, Long> lineCount = lines.count();

Since the initial snippet is just creating a pair with two copies of the
input string, I believe that would accomplish what you're after.  If you
need the String twice with the count you could add a MapFn afterwards to
create whatever Tuple structure you need.

Thanks,
     Dave


On Wed, Mar 11, 2015 at 9:41 AM Kristoffer Sjögren <stoffe@gmail.com> wrote:

> Hi Micah
>
> Ah yes, i'm using the static import from Writables.string().
>
> Cheers,
> -Kristoffer
>
> On Wed, Mar 11, 2015 at 2:29 PM, Micah Whitacre <mkwhitacre@gmail.com>
> wrote:
>
>> Kristoffer,
>>   What PTypeFamily are you using for the "tableOf(strings(),
>> strings())"?  It looks like you are using Writables.strings() up above but
>> looks like you are using static imports down below so wasn't sure if you
>> had switched to AvroTypeFamily instead.
>>
>> Micah
>>
>> On Wed, Mar 11, 2015 at 8:17 AM, Kristoffer Sjögren <stoffe@gmail.com>
>> wrote:
>>
>>> Hi
>>>
>>> I'm trying to count the occurrence of a key in a grouped table. But the
>>> following code snippet [1] fails [2] when calling count() on a MemPipeline
>>> in version 0.8.2+71-cdh4.6.0.
>>>
>>> Am I using the API incorrectly or is this a bug?
>>>
>>> Cheers,
>>> -Kristoffer
>>>
>>> [1]
>>>
>>> PCollection<String> lines =
>>> MemPipeline.typedCollectionOf(Writables.strings(), input);
>>> lines.parallelDo(new DoFn<String, Pair<String, String>>() {
>>>   @Override
>>>   public void process(String input, Emitter<Pair<String, String>>
>>> emitter) {
>>>     emitter.emit(Pair.of(input, input));
>>>   }
>>> }, tableOf(strings(), strings()))
>>> .groupByKey()
>>> .count();
>>>
>>> [2]
>>>
>>> java.lang.IllegalArgumentException: Key type must be of class
>>> WritableType
>>> at org.apache.crunch.types.writable.Writables.tableOf(Writables.java:351)
>>> at
>>> org.apache.crunch.types.writable.WritableTypeFamily.tableOf(WritableTypeFamily.java:95)
>>> at org.apache.crunch.lib.Aggregate.count(Aggregate.java:65)
>>> at org.apache.crunch.lib.Aggregate.count(Aggregate.java:56)
>>> at
>>> org.apache.crunch.impl.mem.collect.MemCollection.count(MemCollection.java:230)
>>> at
>>> mapred.functions.FunctionsTest.testGroupActionCount(FunctionsTest.java:79)
>>>
>>
>>
>

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