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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)

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