public FloatColumn logN(){
  FloatColumn newColumn=FloatColumn.create(name() + "[logN]",size());
  for (  float value : this) {
    newColumn.add((float)Math.log(value));
  }
  return newColumn;
}

public FloatColumn logN ( ) { FloatColumn newColumn = FloatColumn . create ( name ( ) + "[logN]" , size ( ) ) ; for ( float value : this ) { newColumn . add ( ( float ) Math . log ( value ) ) ; } return newColumn ; }
returns the natural log of the values in this column as a new floatcolumn
