好奇怪:::
<br />
require(rmr2)</p>
<p>from.dfs(mapreduce(input = groups2, map = function(k,v) keyval(v, 1),<br />
reduce = function(k,vv) keyval(k, length(vv)),<br />
output = '/user/yibo/tmp'))</p>
<p>$key<br />
[1] 6 8 9 10 11 12 13 14 15 16 17 19<br />
$val<br />
[1] 1 1 5 4 9 7 5 6 4 2 4 2</p>
<p>system('hadoop fs -cat /user/yibo/tmp/part-00000')<br />
SEQ/org@3yibo@chen:~$ edbytes.TypedBytesWritable/org.apache.hadoop.typedbytes.TypedBytesWritablel\�������b�"</p>
<p>from.dfs(mapreduce(input = groups2, map = function(k,v) keyval(v, 1),<br />
reduce = function(k,vv) keyval(k, length(vv)),<br />
output.format='text',<br />
output = '/user/yibo/tmp2'))</p>
<p>$key<br />
[1] 0 4 8 12 17 22 27 32 37 42 47 52<br />
$val<br />
[1] "6\t1" "8\t1" "9\t5" "10\t4" "11\t9" "12\t7" "13\t5" "14\t6" "15\t4"<br />
[10] "16\t2" "17\t4" "19\t2"</p>
<p>system('hadoop fs -cat /user/yibo/tmp2/part-00000')<br />
6 1<br />
8 1<br />
9 5<br />
10 4<br />
11 9<br />
12 7<br />
13 5<br />
14 6<br />
15 4<br />
16 2<br />
17 4<br />
19 2<br />
</p>