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/*
 * 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.math3.linear;

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

import org.apache.commons.math3.exception.MathParseException;
import org.apache.commons.math3.util.CompositeFormat;

/**
 * Formats a {@code nxm} matrix in components list format
 * "{{a00,a01, ...,
 * a0m-1},{a10,
 * a11, ..., a1m-1},{...},{
 * an-10, an-11, ...,
 * an-1m-1}}".
 * 

The prefix and suffix "{" and "}", the row prefix and suffix "{" and "}", * the row separator "," and the column separator "," can be replaced by any * user-defined strings. The number format for components can be configured.

* *

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 matrix 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.

* *

Note: the grouping functionality of the used {@link NumberFormat} is * disabled to prevent problems when parsing (e.g. 1,345.34 would be a valid number * but conflicts with the default column separator).

* * @since 3.1 */ public class RealMatrixFormat { /** The default prefix: "{". */ private static final String DEFAULT_PREFIX = "{"; /** The default suffix: "}". */ private static final String DEFAULT_SUFFIX = "}"; /** The default row prefix: "{". */ private static final String DEFAULT_ROW_PREFIX = "{"; /** The default row suffix: "}". */ private static final String DEFAULT_ROW_SUFFIX = "}"; /** The default row separator: ",". */ private static final String DEFAULT_ROW_SEPARATOR = ","; /** The default column separator: ",". */ private static final String DEFAULT_COLUMN_SEPARATOR = ","; /** Prefix. */ private final String prefix; /** Suffix. */ private final String suffix; /** Row prefix. */ private final String rowPrefix; /** Row suffix. */ private final String rowSuffix; /** Row separator. */ private final String rowSeparator; /** Column separator. */ private final String columnSeparator; /** The format used for components. */ private final NumberFormat format; /** * Create an instance with default settings. *

The instance uses the default prefix, suffix and row/column separator: * "[", "]", ";" and ", " and the default number format for components.

*/ public RealMatrixFormat() { this(DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_ROW_PREFIX, DEFAULT_ROW_SUFFIX, DEFAULT_ROW_SEPARATOR, DEFAULT_COLUMN_SEPARATOR, CompositeFormat.getDefaultNumberFormat()); } /** * Create an instance with a custom number format for components. * @param format the custom format for components. */ public RealMatrixFormat(final NumberFormat format) { this(DEFAULT_PREFIX, DEFAULT_SUFFIX, DEFAULT_ROW_PREFIX, DEFAULT_ROW_SUFFIX, DEFAULT_ROW_SEPARATOR, DEFAULT_COLUMN_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 rowPrefix row prefix to use instead of the default "{" * @param rowSuffix row suffix to use instead of the default "}" * @param rowSeparator tow separator to use instead of the default ";" * @param columnSeparator column separator to use instead of the default ", " */ public RealMatrixFormat(final String prefix, final String suffix, final String rowPrefix, final String rowSuffix, final String rowSeparator, final String columnSeparator) { this(prefix, suffix, rowPrefix, rowSuffix, rowSeparator, columnSeparator, CompositeFormat.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 rowPrefix row prefix to use instead of the default "{" * @param rowSuffix row suffix to use instead of the default "}" * @param rowSeparator tow separator to use instead of the default ";" * @param columnSeparator column separator to use instead of the default ", " * @param format the custom format for components. */ public RealMatrixFormat(final String prefix, final String suffix, final String rowPrefix, final String rowSuffix, final String rowSeparator, final String columnSeparator, final NumberFormat format) { this.prefix = prefix; this.suffix = suffix; this.rowPrefix = rowPrefix; this.rowSuffix = rowSuffix; this.rowSeparator = rowSeparator; this.columnSeparator = columnSeparator; this.format = format; // disable grouping to prevent parsing problems this.format.setGroupingUsed(false); } /** * Get the set of locales for which real vectors formats are available. *

This is the same set as the {@link NumberFormat} set.

* @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 prefix. * @return format prefix. */ public String getRowPrefix() { return rowPrefix; } /** * Get the format suffix. * @return format suffix. */ public String getRowSuffix() { return rowSuffix; } /** * Get the format separator between rows of the matrix. * @return format separator for rows. */ public String getRowSeparator() { return rowSeparator; } /** * Get the format separator between components. * @return format separator between components. */ public String getColumnSeparator() { return columnSeparator; } /** * 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 RealMatrixFormat 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 RealMatrixFormat getInstance(final Locale locale) { return new RealMatrixFormat(CompositeFormat.getDefaultNumberFormat(locale)); } /** * This method calls {@link #format(RealMatrix,StringBuffer,FieldPosition)}. * * @param m RealMatrix object to format. * @return a formatted matrix. */ public String format(RealMatrix m) { return format(m, new StringBuffer(), new FieldPosition(0)).toString(); } /** * Formats a {@link RealMatrix} object to produce a string. * @param matrix 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(RealMatrix matrix, StringBuffer toAppendTo, FieldPosition pos) { pos.setBeginIndex(0); pos.setEndIndex(0); // format prefix toAppendTo.append(prefix); // format rows final int rows = matrix.getRowDimension(); for (int i = 0; i < rows; ++i) { toAppendTo.append(rowPrefix); for (int j = 0; j < matrix.getColumnDimension(); ++j) { if (j > 0) { toAppendTo.append(columnSeparator); } CompositeFormat.formatDouble(matrix.getEntry(i, j), format, toAppendTo, pos); } toAppendTo.append(rowSuffix); if (i < rows - 1) { toAppendTo.append(rowSeparator); } } // format suffix toAppendTo.append(suffix); return toAppendTo; } /** * Parse a string to produce a {@link RealMatrix} object. * * @param source String to parse. * @return the parsed {@link RealMatrix} object. * @throws MathParseException if the beginning of the specified string * cannot be parsed. */ public RealMatrix parse(String source) { final ParsePosition parsePosition = new ParsePosition(0); final RealMatrix result = parse(source, parsePosition); if (parsePosition.getIndex() == 0) { throw new MathParseException(source, parsePosition.getErrorIndex(), Array2DRowRealMatrix.class); } return result; } /** * Parse a string to produce a {@link RealMatrix} object. * * @param source String to parse. * @param pos input/ouput parsing parameter. * @return the parsed {@link RealMatrix} object. */ public RealMatrix parse(String source, ParsePosition pos) { int initialIndex = pos.getIndex(); final String trimmedPrefix = prefix.trim(); final String trimmedSuffix = suffix.trim(); final String trimmedRowPrefix = rowPrefix.trim(); final String trimmedRowSuffix = rowSuffix.trim(); final String trimmedColumnSeparator = columnSeparator.trim(); final String trimmedRowSeparator = rowSeparator.trim(); // parse prefix CompositeFormat.parseAndIgnoreWhitespace(source, pos); if (!CompositeFormat.parseFixedstring(source, trimmedPrefix, pos)) { return null; } // parse components List> matrix = new ArrayList>(); List rowComponents = new ArrayList(); for (boolean loop = true; loop;){ if (!rowComponents.isEmpty()) { CompositeFormat.parseAndIgnoreWhitespace(source, pos); if (!CompositeFormat.parseFixedstring(source, trimmedColumnSeparator, pos)) { if (trimmedRowSuffix.length() != 0 && !CompositeFormat.parseFixedstring(source, trimmedRowSuffix, pos)) { return null; } else { CompositeFormat.parseAndIgnoreWhitespace(source, pos); if (CompositeFormat.parseFixedstring(source, trimmedRowSeparator, pos)) { matrix.add(rowComponents); rowComponents = new ArrayList(); continue; } else { loop = false; } } } } else { CompositeFormat.parseAndIgnoreWhitespace(source, pos); if (trimmedRowPrefix.length() != 0 && !CompositeFormat.parseFixedstring(source, trimmedRowPrefix, pos)) { return null; } } if (loop) { CompositeFormat.parseAndIgnoreWhitespace(source, pos); Number component = CompositeFormat.parseNumber(source, format, pos); if (component != null) { rowComponents.add(component); } else { if (rowComponents.isEmpty()) { loop = false; } else { // invalid component // set index back to initial, error index should already be set pos.setIndex(initialIndex); return null; } } } } if (!rowComponents.isEmpty()) { matrix.add(rowComponents); } // parse suffix CompositeFormat.parseAndIgnoreWhitespace(source, pos); if (!CompositeFormat.parseFixedstring(source, trimmedSuffix, pos)) { return null; } // do not allow an empty matrix if (matrix.isEmpty()) { pos.setIndex(initialIndex); return null; } // build vector double[][] data = new double[matrix.size()][]; int row = 0; for (List rowList : matrix) { data[row] = new double[rowList.size()]; for (int i = 0; i < rowList.size(); i++) { data[row][i] = rowList.get(i).doubleValue(); } row++; } return MatrixUtils.createRealMatrix(data); } }




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