The CBRT() function of Pig Latin is used to calculate the cube root of a given expression.
Here is the syntax of the CBRT() function.
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 calculate the cube root values of the contents of the math.txt file using CBRT() function as shown below.
grunt> cbrt_data = foreach 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; (5.0,1.709975946676697) (16.0,2.5198420997897464) (9.0,2.080083823051904) (2.5,1.3572088082974532) (5.9,1.8069688790571206) (3.1,1.4580997208745365)