pig分析脚本

--读取数据
data = LOAD '/user/mapred/PigData.txt' USING PigStorage('|') AS ( imsi:chararray,time:chararray,loc:chararray);


--转换格式
REGISTER /home/mapred/software/hadoops/pig/pig-0.11.1/contrib/piggybank/java/piggybank.jar;
REGISTER /home/mapred/practise/joda-time-2.0.jar;


DEFINE CustomFormatToISO org.apache.pig.piggybank.evaluation.datetime.convert.CustomFormatToISO();


toISO = FOREACH data GENERATE imsi, CustomFormatToISO( SUBSTRING(time,0,13),'YYYY-MM-dd HH') AS time:chararray,loc;


--数据分组
grp = GROUP toISO BY imsi;


--连续获取数据
REGISTER /home/mapred/practise/datafu-1.2.0.jar
DEFINE MarkovPairs datafu.pig.stats.MarkovPairs();


pairs = FOREACH grp
{
sorted = ORDER toISO BY time;
pair = MarkovPairs(sorted);
GENERATE FLATTEN(pair) AS (data:tuple(imsi,time,loc),next:tuple(imsi,time,loc) );
}


--展开数据
prj = FOREACH pairs GENERATE data.imsi AS imsi,data.time AS time,next.time AS next_time,data.loc AS loc,next.loc AS next_loc;




DEFINE ISODaysBetween org.apache.pig.piggybank.evaluation.datetime.diff.ISODaysBetween();


flt = FILTER prj BY ISODaysBetween(next_time, time) == 0L;




--计算每一个位置的总数


total_count = FOREACH (GROUP flt BY loc) GENERATE group AS loc,COUNT(flt) AS total;


--计算每一对位置的数目
pairs_count = FOREACH (GROUP flt by (loc,next_loc) ) GENERATE FLATTEN(group) AS (loc,next_loc),COUNT(flt) AS cnt;




jnd = JOIN pairs_count BY loc,total_count BY loc USING 'replicated';


prob = FOREACH jnd GENERATE pairs_count::loc AS loc, pairs_count::next_loc AS next_loc,(double)cnt/(double)total AS probability;


top3 = FOREACH (GROUP prob BY loc)
{
sorted = ORDER prob BY probability DESC;
top = LIMIT sorted 3;
GENERATE FLATTEN(top);
};


STORE top3 INTO 'output';


cat output;