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A set of routines to load and manage datasets for machine learning / data mining tasks.
A dataset is a table:
Each column in the table is an attribute, and each row is an instance. Instances have values for each attribute. The whole table is called a relation, and can be given a name.
Creating datasets[procedure] (make-nominal-attribute name value-1 ...)
Creates a nominal attribute with given values, e.g.:
> (make-nominal-attribute 'outlook 'sunny 'overcast 'rainy)[procedure] (make-numeric-attribute name)
Creates a numeric attribute, e.g.:
> (make-numeric-attribute 'temperature)[procedure] (make-relation name attributes data)
Creates a relation with given name. The attributes must be a list of attribute instances, and the data are a list of lists: each sublist representing an instance, and giving the value for that instance of every attribute.
> (make-relation 'plays-tennis (list (make-nominal-attribute 'outlook 'sunny 'overcast 'rainy) (make-nominal-attribute 'temperature 'hot 'mild 'cool) (make-nominal-attribute 'humidity 'high 'normal) (make-nominal-attribute 'windy 'true 'false) (make-nominal-attribute 'plays 'yes 'no)) '((sunny hot high false no) (sunny hot high true no) (overcast hot high false yes) ... (rainy mild high true no)))
Managing datasets[procedure] (attribute-name attribute)
Returns the name of given attribute.[procedure] (attribute-definition attribute)
Returns a definition of the type of given attribute. This definition will be one of:
- '(numeric) for numeric attributes
- '(nominal value-1 ...) for nominal attributes, listing the possible values
Returns the proportion of instances with the given attribute value.[procedure] (entropy relation attribute-name)
Computes entropy of given relation, using attribute-name to divide the relation into groups. attribute-name should be a nominal attribute.[procedure] (filter-instances relation attribute-name value)
Returns a new relation containing those instances of relation which have the given value for attribute-name.[procedure] (find-attribute-index relation attribute-name)
Returns the index number of given attribute name in relation.[procedure] (get-attribute-values relation attribute-name)
Returns the values taken by instances in relation for given attribute name.[procedure] (information-gain relation target-class attribute-name)
Computes the information gain from using the given attribute-name to split the data in relation over the entropy of the data as they are; target-class is used to compute the entropy.[procedure] (relation-attributes relation)
Returns a list of attributes for given relation.[procedure] (relation-data relation)
Returns a list of the instances in the given relation.[procedure] (relation-name relation)
Returns the name of given relation.[procedure] (split-instances relation attribute-name)
Given a nominal attribute, returns a list of relations, each representing instances in relation with the same value for given attribute-name.
Importing Data[procedure] (read-arff filename)
Reads an ARFF definition from given filename, and returns a relation. Currently supports nominal and numeric attribute types, and not sparse files.
GPL version 3.0.