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Diffstat (limited to 'src/main/java/org/apache/commons/math/linear/RealVectorFormat.java')
-rw-r--r-- | src/main/java/org/apache/commons/math/linear/RealVectorFormat.java | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math/linear/RealVectorFormat.java b/src/main/java/org/apache/commons/math/linear/RealVectorFormat.java new file mode 100644 index 0000000..ecefba2 --- /dev/null +++ b/src/main/java/org/apache/commons/math/linear/RealVectorFormat.java @@ -0,0 +1,341 @@ +/* + * 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); + } + +} |