pig tutorial - apache pig tutorial - Apache Pig - CBRT() - pig latin - apache pig - pig hadoop
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)