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Diffstat (limited to 'src/main/java/org/apache/commons/math3/linear/RealMatrixFormat.java')
| -rw-r--r-- | src/main/java/org/apache/commons/math3/linear/RealMatrixFormat.java | 442 |
1 files changed, 442 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math3/linear/RealMatrixFormat.java b/src/main/java/org/apache/commons/math3/linear/RealMatrixFormat.java new file mode 100644 index 0000000..d4eee6b --- /dev/null +++ b/src/main/java/org/apache/commons/math3/linear/RealMatrixFormat.java @@ -0,0 +1,442 @@ +/* + * 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 org.apache.commons.math3.exception.MathParseException; +import org.apache.commons.math3.util.CompositeFormat; + +import java.text.FieldPosition; +import java.text.NumberFormat; +import java.text.ParsePosition; +import java.util.ArrayList; +import java.util.List; +import java.util.Locale; + +/** + * Formats a {@code nxm} matrix in components list format + * "{{a<sub>0</sub><sub>0</sub>,a<sub>0</sub><sub>1</sub>, ..., + * a<sub>0</sub><sub>m-1</sub>},{a<sub>1</sub><sub>0</sub>, a<sub>1</sub><sub>1</sub>, ..., + * a<sub>1</sub><sub>m-1</sub>},{...},{ a<sub>n-1</sub><sub>0</sub>, a<sub>n-1</sub><sub>1</sub>, + * ..., a<sub>n-1</sub><sub>m-1</sub>}}". + * + * <p>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. + * + * <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 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. + * + * <p><b>Note:</b> 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. + * + * <p>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. + * + * <p>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<List<Number>> matrix = new ArrayList<List<Number>>(); + List<Number> rowComponents = new ArrayList<Number>(); + 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<Number>(); + 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<Number> 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); + } +} |