SUM, AVG, in Pig are not working - hadoop

Question

I am analyzing Cluster user log files with the following code in pig:
t_data = load 'log_flies/*' using PigStorage(',');
A = foreach t_data generate $0 as (jobid:int),
$1 as (indexid:int), $2 as (clusterid:int), $6 as (user:chararray),
$7 as (stat:chararray), $13 as (queue:chararray), $32 as (projectName:chararray), $52 as (cpu_used:float), $55 as (efficiency:float), $59 as (numThreads:int),
$61 as (numNodes:int), $62 as (numCPU:int),$72 as (comTime:int),
$73 as (penTime:int), $75 as (runTime:int), $52/($62*$75) as (allEff: float), SUBSTRING($68, 0, 11) as (endTime: chararray);
---describe A;
A = foreach A generate jobid, indexid, clusterid, user, cpu_used, numThreads, runTime, allEff, endTime;
B = group A by user;
f_data = foreach B {
grp = group;
count = COUNT(A);
avg = AVG(A.cpu_used);
generate FLATTEN(grp), count, avg;
};
f_data = limit f_data 10;
dump f_data;
Code works for group and COUNT but when I includes AVG and SUM, it shows the errors:
ERROR org.apache.pig.tools.grunt.Grunt - ERROR 1066: Unable to open
iterator for alias f_data
I checked data types. All are fine. Do you have any suggestions where I missed it?. Thank you in advance for your help.

Answer 1

Its an syntax error. Read http://chimera.labs.oreilly.com/books/1234000001811/ch06.html#more_on_foreach (section : Nested foreach) for details.
Pig Script
A = LOAD 'a.csv' USING PigStorage(',') AS (user:chararray, cpu_used:float);
B = GROUP A BY user;
C = FOREACH B {
cpu_used_bag = A.cpu_used;
GENERATE group AS user, AVG(cpu_used_bag) AS avg_cpu_used, SUM(cpu_used_bag) AS total_cpu_used;
};
Input : a.csv
a,3
a,4
b,5
Output :
(a,3.5,7.0)
(b,5.0,5.0)

Answer 2

Your pig is full of errors
do not use same Alias at both side of = ;
using PigLoader() as (mention your schema appropriately );
A = foreach A generate jobid, indexid, clusterid, user, cpu_used, numThreads, runTime, allEff, endTime;
CHANGE THIS TO
F = foreach A generate jobid, indexid, clusterid, user, cpu_used, numThreads, runTime, allEff, endTime;
f_data = limit f_data 10;
CHANGE left F_data with someother name .
Stop making your life complex.
General rule of debugging Pigscript
run in local mode
dump after everyline
Wrote a sample pig to mimic ur pig :(working)
t_data = load './file' using PigStorage(',') as (jobid:int,cpu_used:float);
C = foreach t_data generate jobid, cpu_used ;
B = group C by jobid ;
f_data = foreach B {
count = COUNT(C);
sum = SUM(C.cpu_used);
avg = AVG(C.cpu_used);
generate FLATTEN(group), count,sum,avg;
};
never_f_data = limit f_data 10;
dump never_f_data;