selectWeka: Feature Selection by Weka
In BioSeqClass: Classification for Biological Sequences

Description Usage Arguments Details Author(s)

feature selection by Weka.

1	selectWeka(train, evaluator="CfsSubsetEval", search="BestFirst", n)

`train`	a data frame including the feature matrix and class label of training set.
`evaluator`	a string for the feature selection method used by WEKA. This must be one of the strings "CfsSubsetEval", "ChiSquaredAttributeEval", "InfoGainAttributeEval", or "SVMAttributeEval".
`search`	a string for the search method used by WEKA. This must be one of the strings "BestFirst" or "Ranker".
`n`	an integer for the number of selected features.

Parameter "evaluator" supportes three feature selection methods provided by WEKA: "CfsSubsetEval": Evaluate the worth of a subset of attributes by considering the individual predictive ability of each feature along with the degree of redundancy between them. "ChiSquaredAttributeEval": Evaluate the worth of an attribute by computing the value of the chi-squared statistic with respect to the class. "InfoGainAttributeEval": Evaluate attributes individually by measuring information gain with respect to the class. "SVMAttributeEval": Evaluate the worth of an attribute by using an SVM classifier. Attributes are ranked by the square of the weight assigned by the SVM. Attribute selection for multiclass problems is handled by ranking attributes for each class seperately using a one-vs-all method and then "dealing" from the top of each pile to give a final ranking.

Parameter "search" supportes three feature subset search methods provided by WEKA: "BestFirst": Searches the space of attribute subsets by greedy hillclimbing augmented with a backtracking facility. Setting the number of consecutive non-improving nodes allowed controls the level of backtracking done. Best first may start with the empty set of attributes and search forward, or start with the full set of attributes and search backward, or start at any point and search in both directions (by considering all possible single attribute additions and deletions at a given point). "Ranker": Ranks attributes by their individual evaluations.

Hong Li

BioSeqClass documentation built on April 28, 2020, 9:19 p.m.