MathExpression

Package

weka.filters.unsupervised.attribute

Synopsis

Modify numeric attributes according to a given expression

Options

The table below describes the options available for MathExpression.

Option

Description

expression

Specify the expression to apply. The 'A' letterrefers to the attribute value. MIN,MAX,MEAN,SDrefer respectively to minimum, maximum, mean andstandard deviation of the attribute.
Supported operators are +, -, *, /, pow, log,abs, cos, exp, sqrt, tan, sin, ceil, floor, rint, (, ),A,MEAN, MAX, MIN, SD, COUNT, SUM, SUMSQUARED, ifelse
Eg. pow(A,6)/(MEAN+MAX)*ifelse(A<0,0,sqrt(A))+ifelse(![A>9 && A<15])

ignoreClass

The class index will be unset temporarily before the filter is applied.

ignoreRange

Specify range of attributes to act on. This is a comma separated list of attribute indices, with "first" and "last" valid values. Specify an inclusive range with "-". E.g: "first-3,5,6-10,last".

invertSelection

Determines whether action is to select or unselect. If set to true, only the specified attributes will be modified; If set to false, specified attributes will not be modified.

Capabilities

The table below describes the capabilites of MathExpression.

Capability

Supported

Class

Missing class values, Relational class, Empty nominal class, Nominal class, String class, No class, Numeric class, Binary class, Unary class, Date class

Attributes

Binary attributes, String attributes, Nominal attributes, Numeric attributes, Unary attributes, Relational attributes, Date attributes, Missing values, Empty nominal attributes

Min # of instances

0