Data View Type Class
This type is for data representing some enumerated value. This is an enumeration over a defined, known cardinality set, as expressed through Count. The underlying .NET type is one of the unsigned integer types. Most commonly this will be UInt32, but could alternately be Byte, UInt16, or UInt64. Despite this, the information is not inherently numeric, so, typically, arithmetic is not meaningful. For example, in multi-class classification, the label is typically a class number which is naturally a KeyDataViewType.
Note that for data of this type, a value of 0, being the default value of the representation type, indicates
the missing value since it would not be sensible for the default value to correspond to any one particular specific
value of the set. The first non-missing value for the enumeration of the set is always
For instance, if you had a key value with a Count of 3, then the UInt32 value
would correspond to the missing key value, and one of the values of
3 would be one
of the valid values, and no other values should in principle be used.
Note that in usage and structure, this is quite close in intended usage and structure to so-called "factor variables" in R.
public sealed class KeyDataViewType : Microsoft.ML.Data.PrimitiveDataViewType
type KeyDataViewType = class inherit PrimitiveDataViewType
Public NotInheritable Class KeyDataViewType Inherits PrimitiveDataViewType
Initializes a new instance of the KeyDataViewType class. This differs from the hypothetically more general
KeyDataViewType(Type, UInt64) constructor by taking an Int32 for
Initializes a new instance of the KeyDataViewType class.
Retrieves the hash code.
The string representation of the KeyDataViewType.