pig tutorial - apache pig tutorial - Apache Pig - ABS() - pig latin - apache pig - pig hadoop
What is Apache Pig - ABS()?
- The ABS() function of Pig Latin is used to calculate the absolute value of a given expression.
- In mathematics, the absolute value or modulus. | x. ... of a real number x is the non-negative value of x without regard to its sign.
Syntax:
- Here is the syntax of the ABS() function.
grunt> ABS(expression)
Example:
- Assume that there is a file named wikitechy_math.txt in the HDFSdirectory /pig_data/. This file contains integer and floating point values as shown below.
- wikitechy_math.txt
3
10
15
7.5
2.9
6.5
And, we have loaded this file into Pig with a relation named wikitechy_math_data as shown below.
grunt> wikitechy_math_data = LOAD 'hdfs://localhost:9000/pig_data/ wikitechy_math.txt' USING PigStorage(',')
as (data:float);
Let us calculate the absolute values of the contents of the math.txt file using ABS() as shown below.
grunt> abs_data = foreach wikitechy_math_data generate (data), ABS(data);
The above statement stores the result in the relation named abs_data. Verify the contents of the relation using the Dump operator as shown below.
grunt> Dump abs_data;
(3.0,3.0)
(10.0,10.0)
(15.0,15.0)
(7.5,7.5)
(2.9,2.9)
(6.5,6.5)