# ColumnConcatenatingEstimator Class

## Definition

Concatenates one or more input columns into a new output column.

public sealed class ColumnConcatenatingEstimator : Microsoft.ML.IEstimator<Microsoft.ML.Data.ColumnConcatenatingTransformer>
type ColumnConcatenatingEstimator = class
interface IEstimator<ColumnConcatenatingTransformer>
Public NotInheritable Class ColumnConcatenatingEstimator
Implements IEstimator(Of ColumnConcatenatingTransformer)
Inheritance
ColumnConcatenatingEstimator
Implements

## Remarks

### Estimator Characteristics

Does this estimator need to look at the data to train its parameters? No
Input column data type Any, except key type. All input columns must have the same type.
Output column data type A vector of the input columns' data type

The resulting ColumnConcatenatingTransformer creates a new column, named as specified in the output column name parameters, where the input values are concatenated in a vector. The order of the concatenation follows the order in which the input columns are specified.

If the input columns' data type is a vector the output column data type remains the same. However, the size of the vector will be the sum of the sizes of the input vectors.