code: public static Distribution guessC(DataSet d)
      {
          double maxLambda = LinearTools.maxLambdaLogisticL1((ClassificationDataSet) d);
          double minC = 1/(2*maxLambda*d.size());
          return new LogUniform(minC*10, minC*1000);
      }
docs: Guess the distribution to use for the regularization term
  {@link #setC(double) C} in Logistic Regression.
  
  @param d the data set to get the guess for
  @return the guess for the C parameter