The ROUND() function is used to get the value of an expression rounded to an integer (if the result type is float) or rounded to a long (if the result type is double).
Assume that there is a file named math.txt in the HDFS directory /pig_data/. This file contains integer and floating point values as shown below.
5 16 9 2.5 5.9 3.1
And, we have loaded this file into Pig with a relation named math_data as shown below.
grunt> math_data = LOAD 'hdfs://localhost:9000/pig_data/math.txt' USING PigStorage(',') as (data:float);
Let us now generate round values of the contents of the math.txt file using ROUND() function as shown below.
grunt> round_data = foreach math_data generate (data), ROUND(data);
The above statement stores the result in the relation named round_data. Verify the contents of the relation using the Dump operator as shown below.
grunt> Dump round_data; (5.0,5) (16.0,16) (9.0,9) (2.5,3) (5.9,6) (3.1,3)