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What is Apache Pig ATAN()?
- The ATAN() function of Pig Latin is used to calculate the arc tan value of a given expression.
Syntax:
Here is the syntax of the ATAN() function.
grunt> ATAN(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
5
16
9
2.5
5.9
3.1
- 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 arc tan values of the contents of the wikitechy_math.txt file using ATAN() function as shown below.
grunt> atan_data = foreach wikitechy_math_data generate (data), ATAN(data);
- The above statement stores the result in the relation named asin_data. Verify the contents of the relation using the Dump operator as shown below.
grunt> Dump atan_data;
(5.0,1.373400766945016)
(16.0,1.5083775167989393)
(9.0,1.460139105621001)
(2.5,1.1902899496825317)
(5.9,1.4029004062076729)
(3.1,1.2587541962439153)