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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.complex; import java.text.FieldPosition; import java.text.NumberFormat; import java.text.ParsePosition; import java.util.Locale; import org.apache.commons.math3.exception.MathIllegalArgumentException; import org.apache.commons.math3.exception.MathParseException; import org.apache.commons.math3.exception.NoDataException; import org.apache.commons.math3.exception.NullArgumentException; import org.apache.commons.math3.exception.util.LocalizedFormats; import org.apache.commons.math3.util.CompositeFormat; /** * Formats a Complex number in cartesian format "Re(c) + Im(c)i". 'i' can * be replaced with 'j' (or anything else), and the number format for both real * and imaginary parts can be configured. * * @version $Id: ComplexFormat.java 1416643 2012-12-03 19:37:14Z tn $ */ public class ComplexFormat { /** The default imaginary character. */ private static final String DEFAULT_IMAGINARY_CHARACTER = "i"; /** The notation used to signify the imaginary part of the complex number. */ private final String imaginaryCharacter; /** The format used for the imaginary part. */ private final NumberFormat imaginaryFormat; /** The format used for the real part. */ private final NumberFormat realFormat; /** * Create an instance with the default imaginary character, 'i', and the * default number format for both real and imaginary parts. */ public ComplexFormat() { this.imaginaryCharacter = DEFAULT_IMAGINARY_CHARACTER; this.imaginaryFormat = CompositeFormat.getDefaultNumberFormat(); this.realFormat = imaginaryFormat; } /** * Create an instance with a custom number format for both real and * imaginary parts. * @param format the custom format for both real and imaginary parts. * @throws NullArgumentException if {@code realFormat} is {@code null}. */ public ComplexFormat(NumberFormat format) throws NullArgumentException { if (format == null) { throw new NullArgumentException(LocalizedFormats.IMAGINARY_FORMAT); } this.imaginaryCharacter = DEFAULT_IMAGINARY_CHARACTER; this.imaginaryFormat = format; this.realFormat = format; } /** * Create an instance with a custom number format for the real part and a * custom number format for the imaginary part. * @param realFormat the custom format for the real part. * @param imaginaryFormat the custom format for the imaginary part. * @throws NullArgumentException if {@code imaginaryFormat} is {@code null}. * @throws NullArgumentException if {@code realFormat} is {@code null}. */ public ComplexFormat(NumberFormat realFormat, NumberFormat imaginaryFormat) throws NullArgumentException { if (imaginaryFormat == null) { throw new NullArgumentException(LocalizedFormats.IMAGINARY_FORMAT); } if (realFormat == null) { throw new NullArgumentException(LocalizedFormats.REAL_FORMAT); } this.imaginaryCharacter = DEFAULT_IMAGINARY_CHARACTER; this.imaginaryFormat = imaginaryFormat; this.realFormat = realFormat; } /** * Create an instance with a custom imaginary character, and the default * number format for both real and imaginary parts. * @param imaginaryCharacter The custom imaginary character. * @throws NullArgumentException if {@code imaginaryCharacter} is * {@code null}. * @throws NoDataException if {@code imaginaryCharacter} is an * empty string. */ public ComplexFormat(String imaginaryCharacter) throws NullArgumentException, NoDataException { this(imaginaryCharacter, CompositeFormat.getDefaultNumberFormat()); } /** * Create an instance with a custom imaginary character, and a custom number * format for both real and imaginary parts. * @param imaginaryCharacter The custom imaginary character. * @param format the custom format for both real and imaginary parts. * @throws NullArgumentException if {@code imaginaryCharacter} is * {@code null}. * @throws NoDataException if {@code imaginaryCharacter} is an * empty string. * @throws NullArgumentException if {@code format} is {@code null}. */ public ComplexFormat(String imaginaryCharacter, NumberFormat format) throws NullArgumentException, NoDataException { this(imaginaryCharacter, format, format); } /** * Create an instance with a custom imaginary character, a custom number * format for the real part, and a custom number format for the imaginary * part. * * @param imaginaryCharacter The custom imaginary character. * @param realFormat the custom format for the real part. * @param imaginaryFormat the custom format for the imaginary part. * @throws NullArgumentException if {@code imaginaryCharacter} is * {@code null}. * @throws NoDataException if {@code imaginaryCharacter} is an * empty string. * @throws NullArgumentException if {@code imaginaryFormat} is {@code null}. * @throws NullArgumentException if {@code realFormat} is {@code null}. */ public ComplexFormat(String imaginaryCharacter, NumberFormat realFormat, NumberFormat imaginaryFormat) throws NullArgumentException, NoDataException { if (imaginaryCharacter == null) { throw new NullArgumentException(); } if (imaginaryCharacter.length() == 0) { throw new NoDataException(); } if (imaginaryFormat == null) { throw new NullArgumentException(LocalizedFormats.IMAGINARY_FORMAT); } if (realFormat == null) { throw new NullArgumentException(LocalizedFormats.REAL_FORMAT); } this.imaginaryCharacter = imaginaryCharacter; this.imaginaryFormat = imaginaryFormat; this.realFormat = realFormat; } /** * Get the set of locales for which complex formats are available. * <p>This is the same set as the {@link NumberFormat} set.</p> * @return available complex format locales. */ public static Locale[] getAvailableLocales() { return NumberFormat.getAvailableLocales(); } /** * This method calls {@link #format(Object,StringBuffer,FieldPosition)}. * * @param c Complex object to format. * @return A formatted number in the form "Re(c) + Im(c)i". */ public String format(Complex c) { return format(c, new StringBuffer(), new FieldPosition(0)).toString(); } /** * This method calls {@link #format(Object,StringBuffer,FieldPosition)}. * * @param c Double object to format. * @return A formatted number. */ public String format(Double c) { return format(new Complex(c, 0), new StringBuffer(), new FieldPosition(0)).toString(); } /** * Formats a {@link Complex} object to produce a string. * * @param complex 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(Complex complex, StringBuffer toAppendTo, FieldPosition pos) { pos.setBeginIndex(0); pos.setEndIndex(0); // format real double re = complex.getReal(); CompositeFormat.formatDouble(re, getRealFormat(), toAppendTo, pos); // format sign and imaginary double im = complex.getImaginary(); StringBuffer imAppendTo; if (im < 0.0) { toAppendTo.append(" - "); imAppendTo = formatImaginary(-im, new StringBuffer(), pos); toAppendTo.append(imAppendTo); toAppendTo.append(getImaginaryCharacter()); } else if (im > 0.0 || Double.isNaN(im)) { toAppendTo.append(" + "); imAppendTo = formatImaginary(im, new StringBuffer(), pos); toAppendTo.append(imAppendTo); toAppendTo.append(getImaginaryCharacter()); } return toAppendTo; } /** * Format the absolute value of the imaginary part. * * @param absIm Absolute value of the imaginary part of a complex number. * @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. */ private StringBuffer formatImaginary(double absIm, StringBuffer toAppendTo, FieldPosition pos) { pos.setBeginIndex(0); pos.setEndIndex(0); CompositeFormat.formatDouble(absIm, getImaginaryFormat(), toAppendTo, pos); if (toAppendTo.toString().equals("1")) { // Remove the character "1" if it is the only one. toAppendTo.setLength(0); } return toAppendTo; } /** * Formats a object to produce a string. {@code obj} must be either a * {@link Complex} object or a {@link Number} object. Any other type of * object will result in an {@link IllegalArgumentException} being thrown. * * @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 MathIllegalArgumentException is {@code obj} is not a valid type. */ public StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos) throws MathIllegalArgumentException { StringBuffer ret = null; if (obj instanceof Complex) { ret = format((Complex) obj, toAppendTo, pos); } else if (obj instanceof Number) { ret = format(new Complex(((Number) obj).doubleValue(), 0.0), toAppendTo, pos); } else { throw new MathIllegalArgumentException(LocalizedFormats.CANNOT_FORMAT_INSTANCE_AS_COMPLEX, obj.getClass().getName()); } return ret; } /** * Access the imaginaryCharacter. * @return the imaginaryCharacter. */ public String getImaginaryCharacter() { return imaginaryCharacter; } /** * Access the imaginaryFormat. * @return the imaginaryFormat. */ public NumberFormat getImaginaryFormat() { return imaginaryFormat; } /** * Returns the default complex format for the current locale. * @return the default complex format. */ public static ComplexFormat getInstance() { return getInstance(Locale.getDefault()); } /** * Returns the default complex format for the given locale. * @param locale the specific locale used by the format. * @return the complex format specific to the given locale. */ public static ComplexFormat getInstance(Locale locale) { NumberFormat f = CompositeFormat.getDefaultNumberFormat(locale); return new ComplexFormat(f); } /** * Returns the default complex format for the given locale. * @param locale the specific locale used by the format. * @param imaginaryCharacter Imaginary character. * @return the complex format specific to the given locale. * @throws NullArgumentException if {@code imaginaryCharacter} is * {@code null}. * @throws NoDataException if {@code imaginaryCharacter} is an * empty string. */ public static ComplexFormat getInstance(String imaginaryCharacter, Locale locale) throws NullArgumentException, NoDataException { NumberFormat f = CompositeFormat.getDefaultNumberFormat(locale); return new ComplexFormat(imaginaryCharacter, f); } /** * Access the realFormat. * @return the realFormat. */ public NumberFormat getRealFormat() { return realFormat; } /** * Parses a string to produce a {@link Complex} object. * * @param source the string to parse. * @return the parsed {@link Complex} object. * @throws MathParseException if the beginning of the specified string * cannot be parsed. */ public Complex parse(String source) throws MathParseException { ParsePosition parsePosition = new ParsePosition(0); Complex result = parse(source, parsePosition); if (parsePosition.getIndex() == 0) { throw new MathParseException(source, parsePosition.getErrorIndex(), Complex.class); } return result; } /** * Parses a string to produce a {@link Complex} object. * * @param source the string to parse * @param pos input/ouput parsing parameter. * @return the parsed {@link Complex} object. */ public Complex parse(String source, ParsePosition pos) { int initialIndex = pos.getIndex(); // parse whitespace CompositeFormat.parseAndIgnoreWhitespace(source, pos); // parse real Number re = CompositeFormat.parseNumber(source, getRealFormat(), pos); if (re == null) { // invalid real number // set index back to initial, error index should already be set pos.setIndex(initialIndex); return null; } // parse sign int startIndex = pos.getIndex(); char c = CompositeFormat.parseNextCharacter(source, pos); int sign = 0; switch (c) { case 0: // no sign // return real only complex number return new Complex(re.doubleValue(), 0.0); case '-': sign = -1; break; case '+': sign = 1; break; default: // invalid sign // set index back to initial, error index should be the last // character examined. pos.setIndex(initialIndex); pos.setErrorIndex(startIndex); return null; } // parse whitespace CompositeFormat.parseAndIgnoreWhitespace(source, pos); // parse imaginary Number im = CompositeFormat.parseNumber(source, getRealFormat(), pos); if (im == null) { // invalid imaginary number // set index back to initial, error index should already be set pos.setIndex(initialIndex); return null; } // parse imaginary character if (!CompositeFormat.parseFixedstring(source, getImaginaryCharacter(), pos)) { return null; } return new Complex(re.doubleValue(), im.doubleValue() * sign); } }