org.apache.pig.piggybank.evaluation.math
Class DoubleSignum

java.lang.Object
  org.apache.pig.EvalFunc<Double>
      org.apache.pig.piggybank.evaluation.math.DoubleSignum

public class DoubleSignum
extends EvalFunc<Double>

math.SIGNUM implements a binding to the Java function Math.signum(double). Given a single data atom it Returns the signum function of the argument.

Parameters:

value - Double.

Return Value:

Double

Return Schema:

SIGNUM_inputSchema

Example:

register math.jar;
A = load 'mydata' using PigStorage() as ( float1 );
B = foreach A generate float1, math.SIGNUM(float1);

Author:

ajay garg

See Also:

Math.signum(double),

Field Summary

Fields inherited from class org.apache.pig.EvalFunc

log, pigLogger, reporter, returnType

Constructor Summary

DoubleSignum()

Method Summary

Double	exec(Tuple input) java level API
Schema	outputSchema(Schema input) Report the schema of the output of this UDF.

Methods inherited from class org.apache.pig.EvalFunc

finish, getArgToFuncMapping, getCacheFiles, getLogger, getPigLogger, getReporter, getReturnType, getSchemaName, isAsynchronous, progress, setPigLogger, setReporter, warn

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DoubleSignum

public DoubleSignum()

Method Detail

exec

public Double exec(Tuple input)
            throws IOException

java level API

Specified by:

exec in class EvalFunc<Double>

Parameters:

input - expects a single numeric DataAtom value

output - returns a single numeric DataAtom value, signum function of the argument

Returns:

result, of type T.

Throws:

IOException

outputSchema

public Schema outputSchema(Schema input)

Description copied from class: EvalFunc

Report the schema of the output of this UDF. Pig will make use of this in error checking, optimization, and planning. The schema of input data to this UDF is provided.

Overrides:

outputSchema in class EvalFunc<Double>

Parameters:

input - Schema of the input

Returns:

Schema of the output