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What is Apache Pig - CBRT()?

  • The CBRT() function of Pig Latin is used to calculate the cube root of a given expression.

Syntax

  • Here is the syntax of the CBRT() function.
grunt> CBRT(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

4 
15 
10 
3.5 
6.9 
5.5 
  • 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 now calculate the cube root values of the contents of the wikitechy_math.txt file using CBRT() function as shown below.
grunt> cbrt_data = foreach wikitechy_math_data generate (data), CBRT(data);
  • The above statement stores the result in the relation named cbrt_data. Verify the contents of the relation using the Dump operator as shown below.
grunt> Dump cbrt_data;
 
(4.0,1.709975946676697) 
(15.0,2.5198420997897464) 
(10.0,2.080083823051904) 
(3.5,1.3572088082974532) 
(6.9,1.8069688790571206) 
(5.5,1.4580997208745365) 

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