The ACOS() function of Pig Latin is used to calculate the arc cosine value of a given expression.
Here is the syntax of the ACOS() 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 arc cosine values of the contents of the math.txt file using ACOS() function as shown below.
grunt> acos_data = foreach math_data generate (data), ACOS(data);
The above statement stores the result in the relation named abs_data. Verify the contents of the relation using the Dump operator as shown below.
grunt> Dump acos_data; (5.0,NaN) (16.0,NaN) (9.0,NaN) (2.5,NaN) (5.9,NaN) (3.1,NaN)