Class BinaryEncoder<T>

Namespace

AiDotNet.Preprocessing.Encoders

Assembly

AiDotNet.dll

Encodes categorical features using binary representation.

public class BinaryEncoder<T> : TransformerBase<T, Matrix<T>, Matrix<T>>, IDataTransformer<T, Matrix<T>, Matrix<T>>

Type Parameters

T

The numeric type for calculations (e.g., float, double).

Inheritance

object

TransformerBase<T, Matrix<T>, Matrix<T>>

BinaryEncoder<T>

Implements

IDataTransformer<T, Matrix<T>, Matrix<T>>

Inherited Members

TransformerBase<T, Matrix<T>, Matrix<T>>.NumOps

TransformerBase<T, Matrix<T>, Matrix<T>>.Engine

TransformerBase<T, Matrix<T>, Matrix<T>>.IsFitted

TransformerBase<T, Matrix<T>, Matrix<T>>.ColumnIndices

TransformerBase<T, Matrix<T>, Matrix<T>>.SupportsInverseTransform

TransformerBase<T, Matrix<T>, Matrix<T>>.Fit(Matrix<T>)

TransformerBase<T, Matrix<T>, Matrix<T>>.Transform(Matrix<T>)

TransformerBase<T, Matrix<T>, Matrix<T>>.FitTransform(Matrix<T>)

TransformerBase<T, Matrix<T>, Matrix<T>>.InverseTransform(Matrix<T>)

TransformerBase<T, Matrix<T>, Matrix<T>>.GetFeatureNamesOut(string[])

TransformerBase<T, Matrix<T>, Matrix<T>>.FitCore(Matrix<T>)

TransformerBase<T, Matrix<T>, Matrix<T>>.TransformCore(Matrix<T>)

TransformerBase<T, Matrix<T>, Matrix<T>>.InverseTransformCore(Matrix<T>)

TransformerBase<T, Matrix<T>, Matrix<T>>.ValidateInputData(Matrix<T>)

TransformerBase<T, Matrix<T>, Matrix<T>>.EnsureFitted()

TransformerBase<T, Matrix<T>, Matrix<T>>.GetColumnsToProcess(int)

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

BinaryEncoder first ordinal encodes the categories, then converts those integers to their binary representation. This creates log2(n) columns instead of n columns that one-hot encoding would create.

For Beginners: If you have 8 categories, one-hot creates 8 columns. Binary encoding uses only 3 columns (since 8 = 2^3): - Category 0 → [0, 0, 0] - Category 1 → [0, 0, 1] - Category 2 → [0, 1, 0] - Category 7 → [1, 1, 1]

This is useful for high-cardinality categorical features where one-hot would create too many columns.

Constructors

BinaryEncoder(BinaryEncoderHandleUnknown, int[]?)

Creates a new instance of BinaryEncoder<T>.

public BinaryEncoder(BinaryEncoderHandleUnknown handleUnknown = BinaryEncoderHandleUnknown.AllZeros, int[]? columnIndices = null)

Parameters

handleUnknown BinaryEncoderHandleUnknown

How to handle unknown categories. Defaults to AllZeros.

columnIndices int[]

The column indices to encode, or null for all columns.

Properties

HandleUnknown

Gets how unknown categories are handled.

public BinaryEncoderHandleUnknown HandleUnknown { get; }

Property Value

BinaryEncoderHandleUnknown

NOutputFeatures

Gets the number of output features after transformation.

public int NOutputFeatures { get; }

Property Value

int

SupportsInverseTransform

Gets whether this transformer supports inverse transformation.

public override bool SupportsInverseTransform { get; }

Property Value

bool

Methods

FitCore(Matrix<T>)

Learns the categories and binary encoding from the training data.

protected override void FitCore(Matrix<T> data)

Parameters

data Matrix<T>

The training data matrix.

GetFeatureNamesOut(string[]?)

Gets the output feature names after transformation.

public override string[] GetFeatureNamesOut(string[]? inputFeatureNames = null)

Parameters

inputFeatureNames string[]

Returns

string[]

InverseTransformCore(Matrix<T>)

Reverses the binary encoding to get original category values.

protected override Matrix<T> InverseTransformCore(Matrix<T> data)

Parameters

data Matrix<T>

The binary encoded data.

Returns

Matrix<T>

The original categorical values.

TransformCore(Matrix<T>)

Transforms the data by converting categories to binary representation.

protected override Matrix<T> TransformCore(Matrix<T> data)

Parameters

data Matrix<T>

The data to transform.

Returns

Matrix<T>

The binary encoded data.