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Normalization Class

Data normalization preprocessing filter.
Inheritance Hierarchy
SystemObject
  Accord.Statistics.FiltersBaseFilterNormalizationOptions, Normalization
    Accord.Statistics.FiltersNormalization

Namespace:  Accord.Statistics.Filters
Assembly:  Accord.Statistics (in Accord.Statistics.dll) Version: 3.8.0
Syntax
[SerializableAttribute]
public class Normalization : BaseFilter<NormalizationOptions, Normalization>, 
	IAutoConfigurableFilter, IFilter
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The Normalization type exposes the following members.

Constructors
Properties
  NameDescription
Public propertyActive
Gets or sets whether this filter is active. An inactive filter will repass the input table as output unchanged.
(Inherited from BaseFilterTOptions, TFilter.)
Public propertyColumns
Gets the collection of filter options.
(Inherited from BaseFilterTOptions, TFilter.)
Public propertyItemInt32
Gets options associated with a given variable (data column).
(Inherited from BaseFilterTOptions, TFilter.)
Public propertyItemString
Gets options associated with a given variable (data column).
(Inherited from BaseFilterTOptions, TFilter.)
Public propertyNumberOfInputs
Gets the number of inputs accepted by the model.
(Inherited from BaseFilterTOptions, TFilter.)
Public propertyToken
Gets or sets a cancellation token that can be used to stop the learning algorithm while it is running.
(Inherited from BaseFilterTOptions, TFilter.)
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Methods
  NameDescription
Public methodAdd
Add a new column options definition to the collection.
(Inherited from BaseFilterTOptions, TFilter.)
Public methodApply(DataTable)
Applies the Filter to a DataTable.
(Inherited from BaseFilterTOptions, TFilter.)
Public methodApply(Double)
Applies the Filter to a DataTable.
Public methodApply(DataTable, String)
Applies the Filter to a DataTable.
(Inherited from BaseFilterTOptions, TFilter.)
Public methodApplyInPlace
Applies the Filter to a DataTable.
Public methodDetect(DataTable)
Auto detects the filter options by analyzing a given DataTable.
Public methodDetect(Double)
Auto detects the filter options by analyzing a given matrix.
Public methodEquals
Determines whether the specified object is equal to the current object.
(Inherited from Object.)
Protected methodFinalize
Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object.)
Public methodGetEnumerator
Returns an enumerator that iterates through the collection.
(Inherited from BaseFilterTOptions, TFilter.)
Public methodGetHashCode
Serves as the default hash function.
(Inherited from Object.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Protected methodOnAddingOptions
Called when a new column options definition is being added. Can be used to validate or modify these options beforehand.
(Inherited from BaseFilterTOptions, TFilter.)
Protected methodProcessFilter
Processes the current filter.
(Overrides BaseFilterTOptions, TFilterProcessFilter(DataTable).)
Public methodToString
Returns a string that represents the current object.
(Inherited from Object.)
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Extension Methods
  NameDescription
Public Extension MethodHasMethod
Checks whether an object implements a method with the given name.
(Defined by ExtensionMethods.)
Public Extension MethodIsEqual
Compares two objects for equality, performing an elementwise comparison if the elements are vectors or matrices.
(Defined by Matrix.)
Public Extension MethodTo(Type)Overloaded.
Converts an object into another type, irrespective of whether the conversion can be done at compile time or not. This can be used to convert generic types to numeric types during runtime.
(Defined by ExtensionMethods.)
Public Extension MethodToTOverloaded.
Converts an object into another type, irrespective of whether the conversion can be done at compile time or not. This can be used to convert generic types to numeric types during runtime.
(Defined by ExtensionMethods.)
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Examples

Suppose we have a data table relating the age of a person and its categorical classification, as in "child", "adult" or "elder". The normalization filter can be used to transform the "Age" column into Z-scores, as shown below:

// Create the aforementioned sample table
DataTable table = new DataTable("Sample data");
table.Columns.Add("Age", typeof(double));
table.Columns.Add("Label", typeof(string));

//            age   label
table.Rows.Add(10, "child");
table.Rows.Add(07, "child");
table.Rows.Add(04, "child");
table.Rows.Add(21, "adult");
table.Rows.Add(27, "adult");
table.Rows.Add(12, "child");
table.Rows.Add(79, "elder");
table.Rows.Add(40, "adult");
table.Rows.Add(30, "adult");

// The filter will ignore non-real (continuous) data
Normalization normalization = new Normalization(table);

double mean = normalization["Age"].Mean;              // 25.55
double sdev = normalization["Age"].StandardDeviation; // 23.29

// Now we can process another table at once:
DataTable result = normalization.Apply(table);

// The result will be a table with the same columns, but
// in which any column named "Age" will have been normalized
// using the previously detected mean and standard deviation:

DataGridBox.Show(result);

The resulting data is shown below:

See Also