Apache Pig - COS()


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The COS() function of Pig Latin is used to calculate the cosine value of a given expression.

Syntax

Here is the syntax of the COS() function.

grunt> COS(expression)

Example

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.

math.txt

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)

Now, let’s calculate the cosine values of the contents of the math.txt file using COS() function as shown below.

grunt> cos_data = foreach math_data generate (data), COS(data);

The above statement stores the result in the relation named cos_data. Verify the contents of the relation using the Dump operator as shown below.

grunt> Dump cos_data;
 
(5.0,0.28366218546322625) 
(16.0,-0.9576594803233847) 
(9.0,-0.9111302618846769) 
(2.5,-0.8011436155469337) 
(5.9,0.9274784663996888) 
(3.1,-0.999135146307834) 
apache_pig_math_functions.htm
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