Java tutorial
/* * 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 <http://www.gnu.org/licenses/>. */ /* * AllFilter.java * Copyright (C) 1999-2012 University of Waikato, Hamilton, New Zealand * */ package weka.filters; import weka.core.*; import weka.core.Capabilities.Capability; /** * A simple instance filter that passes all instances directly * through. Basically just for testing purposes. * * @author Len Trigg (trigg@cs.waikato.ac.nz) * @version $Revision$ */ public class AllFilter extends Filter implements Sourcable, WeightedAttributesHandler, WeightedInstancesHandler { /** for serialization */ static final long serialVersionUID = 5022109283147503266L; /** * 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 passes all instances through unmodified." + " Primarily for testing purposes."; } /** * Returns the Capabilities of this filter. * * @return the capabilities of this object * @see Capabilities */ 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 something goes wrong */ public boolean setInputFormat(Instances instanceInfo) throws Exception { super.setInputFormat(instanceInfo); setOutputFormat(instanceInfo); 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. */ public boolean input(Instance instance) { if (getInputFormat() == null) { throw new IllegalStateException("No input instance format defined"); } if (m_NewBatch) { resetQueue(); m_NewBatch = false; } if (instance.dataset() == null) { push((Instance) instance.copy()); } else { push(instance); // push() will make a copy anyway. } return true; } /** * Returns a string that describes the filter as source. The * filter will be contained in a class with the given name (there may * be auxiliary classes), * and will contain two methods with these signatures: * <pre><code> * // converts one row * public static Object[] filter(Object[] i); * // converts a full dataset (first dimension is row index) * public static Object[][] filter(Object[][] i); * </code></pre> * where the array <code>i</code> contains elements that are either * Double, String, with missing values represented as null. The generated * code is public domain and comes with no warranty. * * @param className the name that should be given to the source class. * @param data the dataset used for initializing the filter * @return the object source described by a string * @throws Exception if the source can't be computed */ public String toSource(String className, Instances data) throws Exception { StringBuffer result; result = new StringBuffer(); result.append("class " + className + " {\n"); result.append("\n"); result.append(" /**\n"); result.append(" * filters a single row\n"); result.append(" * \n"); result.append(" * @param i the row to process\n"); result.append(" * @return the processed row\n"); result.append(" */\n"); result.append(" public static Object[] filter(Object[] i) {\n"); result.append(" return i;\n"); result.append(" }\n"); result.append("\n"); result.append(" /**\n"); result.append(" * filters multiple rows\n"); result.append(" * \n"); result.append(" * @param i the rows to process\n"); result.append(" * @return the processed rows\n"); result.append(" */\n"); result.append(" public static Object[][] filter(Object[][] i) {\n"); result.append(" return i;\n"); result.append(" }\n"); result.append("}\n"); return result.toString(); } /** * Returns the revision string. * * @return the revision */ public String getRevision() { return RevisionUtils.extract("$Revision$"); } /** * Main method for testing this class. * * @param argv should contain arguments to the filter: use -h for help */ public static void main(String[] argv) { runFilter(new AllFilter(), argv); } }