src/main/java/org/apache/commons/math/linear/RealVectorFormat.java - platform/external/apache-commons-math - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You under the Apache License, Version 2.0
  * (the "License"); you may not use this file except in compliance with
  * the License.  You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package org.apache.commons.math.linear;

 import java.text.FieldPosition;
 import java.text.NumberFormat;
 import java.text.ParseException;
 import java.text.ParsePosition;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;

 import org.apache.commons.math.MathRuntimeException;
 import org.apache.commons.math.exception.util.LocalizedFormats;
 import org.apache.commons.math.util.CompositeFormat;

 /**
  * Formats a vector in components list format "{v0; v1; ...; vk-1}".
  * <p>The prefix and suffix "{" and "}" and the separator "; " can be replaced by
  * any user-defined strings. The number format for components can be configured.</p>
  * <p>White space is ignored at parse time, even if it is in the prefix, suffix
  * or separator specifications. So even if the default separator does include a space
  * character that is used at format time, both input string "{1;1;1}" and
  * " { 1 ; 1 ; 1 } " will be parsed without error and the same vector will be
  * returned. In the second case, however, the parse position after parsing will be
  * just after the closing curly brace, i.e. just before the trailing space.</p>
  *
  * @version $Revision: 1003886 $ $Date: 2010-10-02 23:04:44 +0200 (sam. 02 oct. 2010) $
  * @since 2.0
  */
 public class RealVectorFormat extends CompositeFormat {

     /** Serializable version identifier */
     private static final long serialVersionUID = -708767813036157690L;

     /** The default prefix: "{". */
     private static final String DEFAULT_PREFIX = "{";

     /** The default suffix: "}". */
     private static final String DEFAULT_SUFFIX = "}";

     /** The default separator: ", ". */
     private static final String DEFAULT_SEPARATOR = "; ";

     /** Prefix. */
     private final String prefix;

     /** Suffix. */
     private final String suffix;

     /** Separator. */
     private final String separator;

     /** Trimmed prefix. */
     private final String trimmedPrefix;

     /** Trimmed suffix. */
     private final String trimmedSuffix;

     /** Trimmed separator. */
     private final String trimmedSeparator;

     /** The format used for components. */
     private final NumberFormat format;

     /**
      * Create an instance with default settings.
      * <p>The instance uses the default prefix, suffix and separator:
      * "{", "}", and "; " and the default number format for components.</p>
      */
     public RealVectorFormat() {
         this(DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_SEPARATOR, getDefaultNumberFormat());
     }

     /**
      * Create an instance with a custom number format for components.
      * @param format the custom format for components.
      */
     public RealVectorFormat(final NumberFormat format) {
         this(DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_SEPARATOR, format);
     }

     /**
      * Create an instance with custom prefix, suffix and separator.
      * @param prefix prefix to use instead of the default "{"
      * @param suffix suffix to use instead of the default "}"
      * @param separator separator to use instead of the default "; "
      */
     public RealVectorFormat(final String prefix, final String suffix,
                             final String separator) {
         this(prefix, suffix, separator, getDefaultNumberFormat());
     }

     /**
      * Create an instance with custom prefix, suffix, separator and format
      * for components.
      * @param prefix prefix to use instead of the default "{"
      * @param suffix suffix to use instead of the default "}"
      * @param separator separator to use instead of the default "; "
      * @param format the custom format for components.
      */
     public RealVectorFormat(final String prefix, final String suffix,
                             final String separator, final NumberFormat format) {
         this.prefix      = prefix;
         this.suffix      = suffix;
         this.separator   = separator;
         trimmedPrefix    = prefix.trim();
         trimmedSuffix    = suffix.trim();
         trimmedSeparator = separator.trim();
         this.format      = format;
     }

     /**
      * Get the set of locales for which real vectors formats are available.
      * <p>This is the same set as the {@link NumberFormat} set.</p>
      * @return available real vector format locales.
      */
     public static Locale[] getAvailableLocales() {
         return NumberFormat.getAvailableLocales();
     }

     /**
      * Get the format prefix.
      * @return format prefix.
      */
     public String getPrefix() {
         return prefix;
     }

     /**
      * Get the format suffix.
      * @return format suffix.
      */
     public String getSuffix() {
         return suffix;
     }

     /**
      * Get the format separator between components.
      * @return format separator.
      */
     public String getSeparator() {
         return separator;
     }

     /**
      * Get the components format.
      * @return components format.
      */
     public NumberFormat getFormat() {
         return format;
     }

     /**
      * Returns the default real vector format for the current locale.
      * @return the default real vector format.
      */
     public static RealVectorFormat getInstance() {
         return getInstance(Locale.getDefault());
     }

     /**
      * Returns the default real vector format for the given locale.
      * @param locale the specific locale used by the format.
      * @return the real vector format specific to the given locale.
      */
     public static RealVectorFormat getInstance(final Locale locale) {
         return new RealVectorFormat(getDefaultNumberFormat(locale));
     }

     /**
      * This static method calls {@link #format(Object)} on a default instance of
      * RealVectorFormat.
      *
      * @param v RealVector object to format
      * @return A formatted vector
      */
     public static String formatRealVector(RealVector v) {
         return getInstance().format(v);
     }

     /**
      * Formats a {@link RealVector} object to produce a string.
      * @param vector the object to format.
      * @param toAppendTo where the text is to be appended
      * @param pos On input: an alignment field, if desired. On output: the
      *            offsets of the alignment field
      * @return the value passed in as toAppendTo.
      */
     public StringBuffer format(RealVector vector, StringBuffer toAppendTo,
                                FieldPosition pos) {

         pos.setBeginIndex(0);
         pos.setEndIndex(0);

         // format prefix
         toAppendTo.append(prefix);

         // format components
         for (int i = 0; i < vector.getDimension(); ++i) {
             if (i > 0) {
                 toAppendTo.append(separator);
             }
             formatDouble(vector.getEntry(i), format, toAppendTo, pos);
         }

         // format suffix
         toAppendTo.append(suffix);

         return toAppendTo;

     }

     /**
      * Formats a object to produce a string.
      * <p><code>obj</code> must be a  {@link RealVector} object. Any other type of
      * object will result in an {@link IllegalArgumentException} being thrown.</p>
      * @param obj the object to format.
      * @param toAppendTo where the text is to be appended
      * @param pos On input: an alignment field, if desired. On output: the
      *            offsets of the alignment field
      * @return the value passed in as toAppendTo.
      * @see java.text.Format#format(java.lang.Object, java.lang.StringBuffer, java.text.FieldPosition)
      * @throws IllegalArgumentException is <code>obj</code> is not a valid type.
      */
     @Override
     public StringBuffer format(Object obj, StringBuffer toAppendTo,
                                FieldPosition pos) {

         if (obj instanceof RealVector) {
             return format( (RealVector)obj, toAppendTo, pos);
         }

         throw MathRuntimeException.createIllegalArgumentException(
               LocalizedFormats.CANNOT_FORMAT_INSTANCE_AS_REAL_VECTOR,
               obj.getClass().getName());

     }

     /**
      * Parses a string to produce a {@link RealVector} object.
      * @param source the string to parse
      * @return the parsed {@link RealVector} object.
      * @exception ParseException if the beginning of the specified string
      *            cannot be parsed.
      */
     public ArrayRealVector parse(String source) throws ParseException {
         ParsePosition parsePosition = new ParsePosition(0);
         ArrayRealVector result = parse(source, parsePosition);
         if (parsePosition.getIndex() == 0) {
             throw MathRuntimeException.createParseException(
                     parsePosition.getErrorIndex(),
                     LocalizedFormats.UNPARSEABLE_REAL_VECTOR, source);
         }
         return result;
     }

     /**
      * Parses a string to produce a {@link RealVector} object.
      * @param source the string to parse
      * @param pos input/ouput parsing parameter.
      * @return the parsed {@link RealVector} object.
      */
     public ArrayRealVector parse(String source, ParsePosition pos) {
         int initialIndex = pos.getIndex();

         // parse prefix
         parseAndIgnoreWhitespace(source, pos);
         if (!parseFixedstring(source, trimmedPrefix, pos)) {
             return null;
         }

         // parse components
         List<Number> components = new ArrayList<Number>();
         for (boolean loop = true; loop;){

             if (!components.isEmpty()) {
                 parseAndIgnoreWhitespace(source, pos);
                 if (!parseFixedstring(source, trimmedSeparator, pos)) {
                     loop = false;
                 }
             }

             if (loop) {
                 parseAndIgnoreWhitespace(source, pos);
                 Number component = parseNumber(source, format, pos);
                 if (component != null) {
                     components.add(component);
                 } else {
                     // invalid component
                     // set index back to initial, error index should already be set
                     pos.setIndex(initialIndex);
                     return null;
                 }
             }

         }

         // parse suffix
         parseAndIgnoreWhitespace(source, pos);
         if (!parseFixedstring(source, trimmedSuffix, pos)) {
             return null;
         }

         // build vector
         double[] data = new double[components.size()];
         for (int i = 0; i < data.length; ++i) {
             data[i] = components.get(i).doubleValue();
         }
         return new ArrayRealVector(data, false);

     }

     /**
      * Parses a string to produce a object.
      * @param source the string to parse
      * @param pos input/ouput parsing parameter.
      * @return the parsed object.
      * @see java.text.Format#parseObject(java.lang.String, java.text.ParsePosition)
      */
     @Override
     public Object parseObject(String source, ParsePosition pos) {
         return parse(source, pos);
     }

 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package org.apache.commons.math.linear;

	import java.text.FieldPosition;
	import java.text.NumberFormat;
	import java.text.ParseException;
	import java.text.ParsePosition;
	import java.util.ArrayList;
	import java.util.List;
	import java.util.Locale;

	import org.apache.commons.math.MathRuntimeException;
	import org.apache.commons.math.exception.util.LocalizedFormats;
	import org.apache.commons.math.util.CompositeFormat;

	/**
	* Formats a vector in components list format "{v0; v1; ...; vk-1}".
	* <p>The prefix and suffix "{" and "}" and the separator "; " can be replaced by
	* any user-defined strings. The number format for components can be configured.</p>
	* <p>White space is ignored at parse time, even if it is in the prefix, suffix
	* or separator specifications. So even if the default separator does include a space
	* character that is used at format time, both input string "{1;1;1}" and
	* " { 1 ; 1 ; 1 } " will be parsed without error and the same vector will be
	* returned. In the second case, however, the parse position after parsing will be
	* just after the closing curly brace, i.e. just before the trailing space.</p>
	*
	* @version $Revision: 1003886 $ $Date: 2010-10-02 23:04:44 +0200 (sam. 02 oct. 2010) $
	* @since 2.0
	*/
	public class RealVectorFormat extends CompositeFormat {

	/** Serializable version identifier */
	private static final long serialVersionUID = -708767813036157690L;

	/** The default prefix: "{". */
	private static final String DEFAULT_PREFIX = "{";

	/** The default suffix: "}". */
	private static final String DEFAULT_SUFFIX = "}";

	/** The default separator: ", ". */
	private static final String DEFAULT_SEPARATOR = "; ";

	/** Prefix. */
	private final String prefix;

	/** Suffix. */
	private final String suffix;

	/** Separator. */
	private final String separator;

	/** Trimmed prefix. */
	private final String trimmedPrefix;

	/** Trimmed suffix. */
	private final String trimmedSuffix;

	/** Trimmed separator. */
	private final String trimmedSeparator;

	/** The format used for components. */
	private final NumberFormat format;

	/**
	* Create an instance with default settings.
	* <p>The instance uses the default prefix, suffix and separator:
	* "{", "}", and "; " and the default number format for components.</p>
	*/
	public RealVectorFormat() {
	this(DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_SEPARATOR, getDefaultNumberFormat());
	}

	/**
	* Create an instance with a custom number format for components.
	* @param format the custom format for components.
	*/
	public RealVectorFormat(final NumberFormat format) {
	this(DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_SEPARATOR, format);
	}

	/**
	* Create an instance with custom prefix, suffix and separator.
	* @param prefix prefix to use instead of the default "{"
	* @param suffix suffix to use instead of the default "}"
	* @param separator separator to use instead of the default "; "
	*/
	public RealVectorFormat(final String prefix, final String suffix,
	final String separator) {
	this(prefix, suffix, separator, getDefaultNumberFormat());
	}

	/**
	* Create an instance with custom prefix, suffix, separator and format
	* for components.
	* @param prefix prefix to use instead of the default "{"
	* @param suffix suffix to use instead of the default "}"
	* @param separator separator to use instead of the default "; "
	* @param format the custom format for components.
	*/
	public RealVectorFormat(final String prefix, final String suffix,
	final String separator, final NumberFormat format) {
	this.prefix = prefix;
	this.suffix = suffix;
	this.separator = separator;
	trimmedPrefix = prefix.trim();
	trimmedSuffix = suffix.trim();
	trimmedSeparator = separator.trim();
	this.format = format;
	}

	/**
	* Get the set of locales for which real vectors formats are available.
	* <p>This is the same set as the {@link NumberFormat} set.</p>
	* @return available real vector format locales.
	*/
	public static Locale[] getAvailableLocales() {
	return NumberFormat.getAvailableLocales();
	}

	/**
	* Get the format prefix.
	* @return format prefix.
	*/
	public String getPrefix() {
	return prefix;
	}

	/**
	* Get the format suffix.
	* @return format suffix.
	*/
	public String getSuffix() {
	return suffix;
	}

	/**
	* Get the format separator between components.
	* @return format separator.
	*/
	public String getSeparator() {
	return separator;
	}

	/**
	* Get the components format.
	* @return components format.
	*/
	public NumberFormat getFormat() {
	return format;
	}

	/**
	* Returns the default real vector format for the current locale.
	* @return the default real vector format.
	*/
	public static RealVectorFormat getInstance() {
	return getInstance(Locale.getDefault());
	}

	/**
	* Returns the default real vector format for the given locale.
	* @param locale the specific locale used by the format.
	* @return the real vector format specific to the given locale.
	*/
	public static RealVectorFormat getInstance(final Locale locale) {
	return new RealVectorFormat(getDefaultNumberFormat(locale));
	}

	/**
	* This static method calls {@link #format(Object)} on a default instance of
	* RealVectorFormat.
	*
	* @param v RealVector object to format
	* @return A formatted vector
	*/
	public static String formatRealVector(RealVector v) {
	return getInstance().format(v);
	}

	/**
	* Formats a {@link RealVector} object to produce a string.
	* @param vector the object to format.
	* @param toAppendTo where the text is to be appended
	* @param pos On input: an alignment field, if desired. On output: the
	* offsets of the alignment field
	* @return the value passed in as toAppendTo.
	*/
	public StringBuffer format(RealVector vector, StringBuffer toAppendTo,
	FieldPosition pos) {

	pos.setBeginIndex(0);
	pos.setEndIndex(0);

	// format prefix
	toAppendTo.append(prefix);

	// format components
	for (int i = 0; i < vector.getDimension(); ++i) {
	if (i > 0) {
	toAppendTo.append(separator);
	}
	formatDouble(vector.getEntry(i), format, toAppendTo, pos);
	}

	// format suffix
	toAppendTo.append(suffix);

	return toAppendTo;

	}

	/**
	* Formats a object to produce a string.
	* <p><code>obj</code> must be a {@link RealVector} object. Any other type of
	* object will result in an {@link IllegalArgumentException} being thrown.</p>
	* @param obj the object to format.
	* @param toAppendTo where the text is to be appended
	* @param pos On input: an alignment field, if desired. On output: the
	* offsets of the alignment field
	* @return the value passed in as toAppendTo.
	* @see java.text.Format#format(java.lang.Object, java.lang.StringBuffer, java.text.FieldPosition)
	* @throws IllegalArgumentException is <code>obj</code> is not a valid type.
	*/
	@Override
	public StringBuffer format(Object obj, StringBuffer toAppendTo,
	FieldPosition pos) {

	if (obj instanceof RealVector) {
	return format( (RealVector)obj, toAppendTo, pos);
	}

	throw MathRuntimeException.createIllegalArgumentException(
	LocalizedFormats.CANNOT_FORMAT_INSTANCE_AS_REAL_VECTOR,
	obj.getClass().getName());

	}

	/**
	* Parses a string to produce a {@link RealVector} object.
	* @param source the string to parse
	* @return the parsed {@link RealVector} object.
	* @exception ParseException if the beginning of the specified string
	* cannot be parsed.
	*/
	public ArrayRealVector parse(String source) throws ParseException {
	ParsePosition parsePosition = new ParsePosition(0);
	ArrayRealVector result = parse(source, parsePosition);
	if (parsePosition.getIndex() == 0) {
	throw MathRuntimeException.createParseException(
	parsePosition.getErrorIndex(),
	LocalizedFormats.UNPARSEABLE_REAL_VECTOR, source);
	}
	return result;
	}

	/**
	* Parses a string to produce a {@link RealVector} object.
	* @param source the string to parse
	* @param pos input/ouput parsing parameter.
	* @return the parsed {@link RealVector} object.
	*/
	public ArrayRealVector parse(String source, ParsePosition pos) {
	int initialIndex = pos.getIndex();

	// parse prefix
	parseAndIgnoreWhitespace(source, pos);
	if (!parseFixedstring(source, trimmedPrefix, pos)) {
	return null;
	}

	// parse components
	List<Number> components = new ArrayList<Number>();
	for (boolean loop = true; loop;){

	if (!components.isEmpty()) {
	parseAndIgnoreWhitespace(source, pos);
	if (!parseFixedstring(source, trimmedSeparator, pos)) {
	loop = false;
	}
	}

	if (loop) {
	parseAndIgnoreWhitespace(source, pos);
	Number component = parseNumber(source, format, pos);
	if (component != null) {
	components.add(component);
	} else {
	// invalid component
	// set index back to initial, error index should already be set
	pos.setIndex(initialIndex);
	return null;
	}
	}

	}

	// parse suffix
	parseAndIgnoreWhitespace(source, pos);
	if (!parseFixedstring(source, trimmedSuffix, pos)) {
	return null;
	}

	// build vector
	double[] data = new double[components.size()];
	for (int i = 0; i < data.length; ++i) {
	data[i] = components.get(i).doubleValue();
	}
	return new ArrayRealVector(data, false);

	}

	/**
	* Parses a string to produce a object.
	* @param source the string to parse
	* @param pos input/ouput parsing parameter.
	* @return the parsed object.
	* @see java.text.Format#parseObject(java.lang.String, java.text.ParsePosition)
	*/
	@Override
	public Object parseObject(String source, ParsePosition pos) {
	return parse(source, pos);
	}

	}