org.datavec.api.transform.transform

Class BaseColumnsMathOpTransform

java.lang.Object

org.datavec.api.transform.transform.BaseColumnsMathOpTransform

All Implemented Interfaces:

Serializable, ColumnOp, Transform

Direct Known Subclasses:

DoubleColumnsMathOpTransform, FloatColumnsMathOpTransform, IntegerColumnsMathOpTransform, LongColumnsMathOpTransform, NDArrayColumnsMathOpTransform

public abstract class BaseColumnsMathOpTransform
extends Object
implements Transform, ColumnOp

Base class for multiple column math operations. For example myNewColumn = column1 + column2 + column3.
Note: this transform adds a (derived) column (with the specified name) to the end

Note: Certain operations have restrictions on the number of columns used as input
Add: 2 or more (a+b+c+...)
Subtract: exactly 2 (a-b)
Multiply: 2 or more (a*b*c*...)
Divide: exactly 2 (a/b)
Modulus: exactly 2 (a%b)
Other math ops (ReverseSubtract, ReverseDivide, ScalarMin, ScalarMax) are not allowed here.

See: IntegerMathOpTransform, DoubleMathOpTransform, LongMathOpTransform for operations with a scalar + single column, instea

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected String[]	columns
protected MathOp	mathOp
protected String	newColumnName

Constructor Summary

Constructors

Constructor and Description
BaseColumnsMathOpTransform(String newColumnName, MathOp mathOp, String... columns)

Method Summary

Modifier and Type	Method and Description
String	columnName() Returns a singular column name this op is meant to run on
String[]	columnNames() Returns column names this op is meant to run on
protected abstract ColumnMetaData	derivedColumnMetaData(String newColumnName, Schema inputSchema)
protected abstract Writable	doOp(Writable... input)
Schema	getInputSchema() Getter for input schema
List<Writable>	map(List<Writable> writables) Transform a writable in to another writable
List<List<Writable>>	mapSequence(List<List<Writable>> sequence) Transform a sequence
String	outputColumnName() The output column name after the operation has been applied
String[]	outputColumnNames() The output column names This will often be the same as the input
void	setInputSchema(Schema inputSchema) Set the input schema.
abstract String	toString()
Schema	transform(Schema inputSchema) Get the output schema for this transformation, given an input schema

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.datavec.api.transform.Transform

map, mapSequence

Field Detail

newColumnName

protected final String newColumnName

mathOp

protected final MathOp mathOp

columns

protected final String[] columns

Constructor Detail

BaseColumnsMathOpTransform

public BaseColumnsMathOpTransform(String newColumnName,
                                  MathOp mathOp,
                                  String... columns)

Method Detail

transform

public Schema transform(Schema inputSchema)

Description copied from interface: ColumnOp

Get the output schema for this transformation, given an input schema

Specified by:

transform in interface ColumnOp

setInputSchema

public void setInputSchema(Schema inputSchema)

Description copied from interface: ColumnOp

Set the input schema.

Specified by:

setInputSchema in interface ColumnOp

getInputSchema

public Schema getInputSchema()

Description copied from interface: ColumnOp

Getter for input schema

Specified by:

getInputSchema in interface ColumnOp

Returns:

map

public List<Writable> map(List<Writable> writables)

Description copied from interface: Transform

Transform a writable in to another writable

Specified by:

map in interface Transform

Parameters:

writables - the record to transform

Returns:

the transformed writable

mapSequence

public List<List<Writable>> mapSequence(List<List<Writable>> sequence)

Description copied from interface: Transform

Transform a sequence

Specified by:

mapSequence in interface Transform

outputColumnName

public String outputColumnName()

The output column name after the operation has been applied

Specified by:

outputColumnName in interface ColumnOp

Returns:

the output column name

outputColumnNames

public String[] outputColumnNames()

The output column names This will often be the same as the input

Specified by:

outputColumnNames in interface ColumnOp

Returns:

the output column names

columnNames

public String[] columnNames()

Returns column names this op is meant to run on

Specified by:

columnNames in interface ColumnOp

Returns:

columnName

public String columnName()

Returns a singular column name this op is meant to run on

Specified by:

columnName in interface ColumnOp

Returns:

derivedColumnMetaData

protected abstract ColumnMetaData derivedColumnMetaData(String newColumnName,
                                                        Schema inputSchema)

doOp

protected abstract Writable doOp(Writable... input)

toString

public abstract String toString()

Overrides:

toString in class Object