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weka.filters.unsupervised.attribute.AddExpression Maven / Gradle / Ivy

/*
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see .
 */

/*
 *    AddExpression.java
 *    Copyright (C) 2000-2012 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.filters.unsupervised.attribute;

import java.util.Enumeration;
import java.util.Vector;

import weka.core.*;
import weka.core.Capabilities.Capability;
import weka.core.expressionlanguage.common.IfElseMacro;
import weka.core.expressionlanguage.common.JavaMacro;
import weka.core.expressionlanguage.common.MacroDeclarationsCompositor;
import weka.core.expressionlanguage.common.MathFunctions;
import weka.core.expressionlanguage.common.Primitives.DoubleExpression;
import weka.core.expressionlanguage.core.Node;
import weka.core.expressionlanguage.parser.Parser;
import weka.core.expressionlanguage.weka.InstancesHelper;
import weka.filters.Filter;
import weka.filters.StreamableFilter;
import weka.filters.UnsupervisedFilter;

/**
 *  An instance filter that creates a new attribute by
 * applying a mathematical expression to existing attributes. The expression can
 * contain attribute references and numeric constants. Supported operators are :

 * +, -, *, /, ^, log, abs, cos, exp, sqrt, floor, ceil, rint, tan, sin, (, )

 * Attributes are specified by prefixing with 'a', eg. a7 is attribute number 7
 * (starting from 1).

 * Example expression : a1^2*a5/log(a7*4.0).
 * 

 * 
 * 
 *  Valid options are:
 * 

 * 
 * 
 * -E <expression>
 *  Specify the expression to apply. Eg a1^2*a5/log(a7*4.0).
 *  Supported opperators: ,+, -, *, /, ^, log, abs, cos, 
 *  exp, sqrt, floor, ceil, rint, tan, sin, (, )
 *  (default: 0.0)
 * 
 * 
 * 
 * -N <name>
 *  Specify the name for the new attribute. (default is the expression provided with -E)
 * 
 * 
 * 
 * -D
 *  Debug. Names attribute with the postfix parse of the expression.
 * 
 * 
 * 
 * 
 * @author Mark Hall ([email protected])
 * @version $Revision: 14508 $
 */
public class AddExpression extends Filter implements UnsupervisedFilter,
  StreamableFilter, OptionHandler, WeightedInstancesHandler, WeightedAttributesHandler {

  /** for serialization */
  static final long serialVersionUID = 402130384261736245L;

  /** The infix expression */
  private String m_infixExpression = "0.0";

  /**
   * Name of the new attribute. "expression" length string will use the provided
   * expression as the new attribute name
   */
  private String m_attributeName = "expression";

  /**
   * If true, makes the attribute name equal to the postfix parse of the
   * expression
   */
  private boolean m_Debug = false;

  private DoubleExpression m_Expression = null;

  private InstancesHelper m_InstancesHelper;

  /**
   * Returns a string describing this filter
   * 
   * @return a description of the filter suitable for displaying in the
   *         explorer/experimenter gui
   */
  public String globalInfo() {
    return "An instance filter that creates a new attribute by applying a "
      + "mathematical expression to existing attributes. The expression "
      + "can contain attribute references and numeric constants. Supported "
      + "operators are :\n"
      + "+, -, *, /, ^, log, abs, cos, exp, sqrt, floor, ceil, rint, tan, "
      + "sin, (, )\n"
      + "Attributes are specified by prefixing with 'a', eg. a7 is "
      + "attribute number 7 (starting from 1).\n"
      + "Example expression : a1^2*a5/log(a7*4.0).";
  }

  /**
   * Returns an enumeration describing the available options.
   * 
   * @return an enumeration of all the available options.
   */
  @Override
  public Enumeration listOptions() {

    Vector newVector = new Vector(3);

    newVector.addElement(new Option(
      "\tSpecify the expression to apply. Eg a1^2*a5/log(a7*4.0)."
        + "\n\tSupported opperators: ,+, -, *, /, ^, log, abs, cos, "
        + "\n\texp, sqrt, floor, ceil, rint, tan, sin, (, )"
        + "\n\t(default: a1^2)", "E", 1, "-E "));

    newVector.addElement(new Option(
      "\tSpecify the name for the new attribute. (default is the "
        + "expression provided with -E)", "N", 1, "-N "));

    newVector
      .addElement(new Option(
        "\tDebug. Names attribute with the postfix parse of the "
          + "expression.", "D", 0, "-D"));

    return newVector.elements();
  }

  /**
   * Parses a given list of options.
   * 

   * 
   *  Valid options are:
   * 

   * 
   * 
   * -E <expression>
   *  Specify the expression to apply. Eg a1^2*a5/log(a7*4.0).
   *  Supported opperators: ,+, -, *, /, ^, log, abs, cos, 
   *  exp, sqrt, floor, ceil, rint, tan, sin, (, )
   *  (default: a1^2)
   * 
   * 
   * 
   * -N <name>
   *  Specify the name for the new attribute. (default is the expression provided with -E)
   * 
   * 
   * 
   * -D
   *  Debug. Names attribute with the postfix parse of the expression.
   * 
   * 
   * 
   * 
   * @param options the list of options as an array of strings
   * @throws Exception if an option is not supported
   */
  @Override
  public void setOptions(String[] options) throws Exception {
    String expString = Utils.getOption('E', options);
    if (expString.length() != 0) {
      setExpression(expString);
    } else {
      setExpression("a1^2");
    }

    String name = Utils.getOption('N', options);
    if (name.length() != 0) {
      setName(name);
    }

    setDebug(Utils.getFlag('D', options));

    Utils.checkForRemainingOptions(options);
  }

  /**
   * Gets the current settings of the filter.
   * 
   * @return an array of strings suitable for passing to setOptions
   */
  @Override
  public String[] getOptions() {

    Vector options = new Vector();

    options.add("-E");
    options.add(getExpression());
    options.add("-N");
    options.add(getName());

    if (getDebug()) {
      options.add("-D");
    }

    return options.toArray(new String[0]);
  }

  /**
   * Returns the tip text for this property
   * 
   * @return tip text for this property suitable for displaying in the
   *         explorer/experimenter gui
   */
  public String nameTipText() {
    return "Set the name of the new attribute.";
  }

  /**
   * Set the name for the new attribute. The string "expression" can be used to
   * make the name of the new attribute equal to the expression provided.
   * 
   * @param name the name of the new attribute
   */
  public void setName(String name) {
    m_attributeName = name;
  }

  /**
   * Returns the name of the new attribute
   * 
   * @return the name of the new attribute
   */
  public String getName() {
    return m_attributeName;
  }

  /**
   * Returns the tip text for this property
   * 
   * @return tip text for this property suitable for displaying in the
   *         explorer/experimenter gui
   */
  public String debugTipText() {
    return "Set debug mode. If true then the new attribute will be named with "
      + "the postfix parse of the supplied expression.";
  }

  /**
   * Set debug mode. Causes the new attribute to be named with the postfix parse
   * of the expression
   * 
   * @param d true if debug mode is to be used
   */
  public void setDebug(boolean d) {
    m_Debug = d;
  }

  /**
   * Gets whether debug is set
   * 
   * @return true if debug is set
   */
  public boolean getDebug() {
    return m_Debug;
  }

  /**
   * Returns the tip text for this property
   * 
   * @return tip text for this property suitable for displaying in the
   *         explorer/experimenter gui
   */
  public String expressionTipText() {
    return "Set the math expression to apply. Eg. a1^2*a5/log(a7*4.0)";
  }

  /**
   * Set the expression to apply
   * 
   * @param expr a mathematical expression to apply
   */
  public void setExpression(String expr) {
    m_infixExpression = expr;
  }

  /**
   * Get the expression
   * 
   * @return the expression
   */
  public String getExpression() {
    return m_infixExpression;
  }

  /**
   * Returns the Capabilities of this filter.
   * 
   * @return the capabilities of this object
   * @see Capabilities
   */
  @Override
  public Capabilities getCapabilities() {
    Capabilities result = super.getCapabilities();
    result.disableAll();

    // attributes
    result.enableAllAttributes();
    result.enable(Capability.MISSING_VALUES);

    // class
    result.enableAllClasses();
    result.enable(Capability.MISSING_CLASS_VALUES);
    result.enable(Capability.NO_CLASS);

    return result;
  }

  /**
   * Sets the format of the input instances.
   * 
   * @param instanceInfo an Instances object containing the input instance
   *          structure (any instances contained in the object are ignored -
   *          only the structure is required).
   * @return true if the outputFormat may be collected immediately
   * @throws Exception if the format couldn't be set successfully
   */
  @Override
  public boolean setInputFormat(Instances instanceInfo) throws Exception {

    m_InstancesHelper = new InstancesHelper(instanceInfo);
    Node node = Parser.parse(
        // expressions string
        m_infixExpression,
        // variables
        m_InstancesHelper,
        // macros
        new MacroDeclarationsCompositor(
            m_InstancesHelper,
            new MathFunctions(),
            new IfElseMacro(),
            new JavaMacro()
            )
        );
    
    if (!(node instanceof DoubleExpression))
      throw new Exception("Expression must be of double type!");
    
    m_Expression = (DoubleExpression) node;

    super.setInputFormat(instanceInfo);

    Instances outputFormat = new Instances(instanceInfo, 0);
    Attribute newAttribute;
    if (m_attributeName.compareTo("expression") != 0) {
      newAttribute = new Attribute(m_attributeName);
    } else {
      newAttribute = new Attribute(m_infixExpression);
    }
    outputFormat.insertAttributeAt(newAttribute, instanceInfo.numAttributes());
    setOutputFormat(outputFormat);
    return true;
  }

  /**
   * Input an instance for filtering. Ordinarily the instance is processed and
   * made available for output immediately. Some filters require all instances
   * be read before producing output.
   * 
   * @param instance the input instance
   * @return true if the filtered instance may now be collected with output().
   * @throws IllegalStateException if no input format has been defined.
   * @throws Exception if there was a problem during the filtering.
   */
  @Override
  public boolean input(Instance instance) throws Exception {

    if (getInputFormat() == null) {
      throw new IllegalStateException("No input instance format defined");
    }
    if (m_NewBatch) {
      resetQueue();
      m_NewBatch = false;
    }

    double[] vals = new double[instance.numAttributes() + 1];
    System.arraycopy(instance.toDoubleArray(), 0, vals, 0, instance.numAttributes());

    m_InstancesHelper.setInstance(instance);
    vals[vals.length - 1] = m_Expression.evaluate();
    if (m_InstancesHelper.missingAccessed())
      vals[vals.length - 1] = Utils.missingValue();

    Instance inst = null;
    if (instance instanceof SparseInstance) {
      inst = new SparseInstance(instance.weight(), vals);
    } else {
      inst = new DenseInstance(instance.weight(), vals);
    }

    copyValues(inst, false, instance.dataset(), outputFormatPeek());

    push(inst); // No need to copy instance
    return true;
  }

  /**
   * Returns the revision string.
   * 
   * @return the revision
   */
  @Override
  public String getRevision() {
    return RevisionUtils.extract("$Revision: 14508 $");
  }

  /**
   * Main method for testing this class.
   * 
   * @param args should contain arguments to the filter: use -h for help
   */
  public static void main(String[] args) {
    runFilter(new AddExpression(), args);
  }
}