The SQRT() function is used to calculate the square root of a given expression.
Here is the syntax of the SQRT() 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 square root values of the contents of the math.txt file using SQRT() function as shown below.
grunt> sqrt_data = foreach math_data generate (data), SQRT(data);
The above statement stores the result in the relation named sqrt_data. Verify the contents of the relation using the Dump operator as shown below.
grunt> Dump sqrt_data; (5.0,2.23606797749979) (16.0,4.0) (9.0,3.0) (2.5,1.5811388300841898) (5.9,2.4289915799292987) (3.1,1.76068165908337)