Examples of weka.filters.unsupervised.attribute.MathExpression

weka.filters.unsupervised.attribute.MathExpression

Modify numeric attributes according to a given expression

Valid options are:

 -unset-class-temporarily Unsets the class index temporarily before the filter is applied to the data. (default: no)

 -E <expression> Specify the expression to apply. Eg. pow(A,6)/(MEAN+MAX) Supported operators are +, -, *, /, pow, log, abs, cos, exp, sqrt, tan, sin, ceil, floor, rint, (, ),  MEAN, MAX, MIN, SD, COUNT, SUM, SUMSQUARED, ifelse

 -R <index1,index2-index4,...> Specify list of columns to ignore. First and last are valid indexes. (default none)

 -V Invert matching sense (i.e. only modify specified columns)

@author Eibe Frank (eibe@cs.waikato.ac.nz) @author Prados Julien (julien.prados@cui.unige.ch) @version $Revision: 5543 $ @see MathematicalExpression

      int index = insts.attribute(field).index();
      if (index < 0) {
        throw new Exception("Can't find field '" + field + "'!");
      }


      MathExpression mathE = new MathExpression();
      mathE.setIgnoreRange("" + (index + 1));
      mathE.setInvertSelection(true);
      mathE.setExpression("log(A)");
      mathE.setInputFormat(insts);
      insts = Filter.useFilter(insts, mathE);
      m_varianceAdjusters.add(mathE);
    }


    return insts;

Examples of weka.filters.unsupervised.attribute.MathExpression

Related Classes of weka.filters.unsupervised.attribute.MathExpression