Replace Missing Values (In Database)
(In-Database Processing)
Synopsis
Replaces missing values in the data.Description
Replaces missing values in examples. If a value is missing, it is replaced by one of the functions "minimum", "maximum", "average", and "none", which is applied to the non missing attribute values of the example set. "none" means that the value is not replaced. The function can be selected using the parameter list columns. If an attribute's name appears in this list as a key, the value is used as the function name. If the attribute's name is not in the list, the function specified by the default parameter is used. The replenishment "value" indicates that the user defined parameter should be used for the replacement. It can be a nominal or a numerical value.
Input
example set input
Output
- example set output
Parameters
- attribute filter type The condition specifies which attributes are selected or affected by this operator.
- attribute The attribute which should be chosen.
- attributes The attribute which should be chosen.
- regular expression A regular expression for the names of the attributes which should be kept.
- use except expression If enabled, an exception to the specified regular expression might be specified. Attributes of matching this will be filtered out, although matching the first expression.
- except regular expression A regular expression for the names of the attributes which should be filtered out although matching the above regular expression.
- value type The value type of the attributes.
- use value type exception If enabled, an exception to the specified value type might be specified. Attributes of this type will be filtered out, although matching the first specified type.
- except value type Except this value type.
- block type The block type of the attributes.
- use block type exception If enabled, an exception to the specified block type might be specified.
- except block type Except this block type.
- numeric condition Parameter string for the condition, e.g. '>= 5'
- invert selection Indicates if only attributes should be accepted which would normally filtered.
- default Function to apply to all columns that are not explicitly specified by parameter 'columns'.
- columns List of replacement functions for each column.
- replenishment value This value is used for some of the replenishment types.