Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||||||
ComplexFormat |
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| 2.1785714285714284;2.179 |
1 | /* |
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2 | * Copyright 2004 The Apache Software Foundation. |
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3 | * |
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4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
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5 | * you may not use this file except in compliance with the License. |
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6 | * You may obtain a copy of the License at |
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7 | * |
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8 | * http://www.apache.org/licenses/LICENSE-2.0 |
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9 | * |
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10 | * Unless required by applicable law or agreed to in writing, software |
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11 | * distributed under the License is distributed on an "AS IS" BASIS, |
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12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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13 | * See the License for the specific language governing permissions and |
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14 | * limitations under the License. |
|
15 | */ |
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16 | ||
17 | package org.apache.commons.math.complex; |
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18 | ||
19 | import java.io.Serializable; |
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20 | import java.text.FieldPosition; |
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21 | import java.text.Format; |
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22 | import java.text.NumberFormat; |
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23 | import java.text.ParseException; |
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24 | import java.text.ParsePosition; |
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25 | import java.util.Locale; |
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26 | ||
27 | /** |
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28 | * Formats a Complex number in cartesian format "Re(c) + Im(c)i". 'i' can |
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29 | * be replaced with 'j', and the number format for both real and imaginary parts |
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30 | * can be configured. |
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31 | * |
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32 | * @author Apache Software Foundation |
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33 | * @version $Revision$ $Date: 2005-06-26 15:20:57 -0700 (Sun, 26 Jun 2005) $ |
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34 | */ |
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35 | public class ComplexFormat extends Format implements Serializable { |
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36 | ||
37 | /** Serializable version identifier */ |
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38 | static final long serialVersionUID = -6337346779577272306L; |
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39 | ||
40 | /** The default imaginary character. */ |
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41 | private static final String DEFAULT_IMAGINARY_CHARACTER = "i"; |
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42 | ||
43 | /** The notation used to signify the imaginary part of the complex number. */ |
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44 | private String imaginaryCharacter; |
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45 | ||
46 | /** The format used for the imaginary part. */ |
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47 | private NumberFormat imaginaryFormat; |
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48 | ||
49 | /** The format used for the real part. */ |
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50 | private NumberFormat realFormat; |
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51 | ||
52 | /** |
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53 | * Create an instance with the default imaginary character, 'i', and the |
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54 | * default number format for both real and imaginary parts. |
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55 | */ |
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56 | public ComplexFormat() { |
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57 | 28 | this(DEFAULT_IMAGINARY_CHARACTER, getDefaultNumberFormat()); |
58 | 28 | } |
59 | ||
60 | /** |
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61 | * Create an instance with a custom number format for both real and |
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62 | * imaginary parts. |
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63 | * @param format the custom format for both real and imaginary parts. |
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64 | */ |
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65 | public ComplexFormat(NumberFormat format) { |
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66 | 284 | this(DEFAULT_IMAGINARY_CHARACTER, format); |
67 | 284 | } |
68 | ||
69 | /** |
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70 | * Create an instance with a custom number format for the real part and a |
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71 | * custom number format for the imaginary part. |
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72 | * @param realFormat the custom format for the real part. |
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73 | * @param imaginaryFormat the custom format for the imaginary part. |
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74 | */ |
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75 | public ComplexFormat(NumberFormat realFormat, |
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76 | NumberFormat imaginaryFormat) { |
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77 | 0 | this(DEFAULT_IMAGINARY_CHARACTER, realFormat, imaginaryFormat); |
78 | 0 | } |
79 | ||
80 | /** |
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81 | * Create an instance with a custom imaginary character, and the default |
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82 | * number format for both real and imaginary parts. |
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83 | * @param imaginaryCharacter The custom imaginary character. |
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84 | */ |
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85 | public ComplexFormat(String imaginaryCharacter) { |
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86 | 0 | this(imaginaryCharacter, getDefaultNumberFormat()); |
87 | 0 | } |
88 | ||
89 | /** |
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90 | * Create an instance with a custom imaginary character, and a custom number |
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91 | * format for both real and imaginary parts. |
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92 | * @param imaginaryCharacter The custom imaginary character. |
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93 | * @param format the custom format for both real and imaginary parts. |
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94 | */ |
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95 | public ComplexFormat(String imaginaryCharacter, NumberFormat format) { |
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96 | 312 | this(imaginaryCharacter, format, (NumberFormat)format.clone()); |
97 | 312 | } |
98 | ||
99 | /** |
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100 | * Create an instance with a custom imaginary character, a custom number |
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101 | * format for the real part, and a custom number format for the imaginary |
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102 | * part. |
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103 | * @param imaginaryCharacter The custom imaginary character. |
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104 | * @param realFormat the custom format for the real part. |
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105 | * @param imaginaryFormat the custom format for the imaginary part. |
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106 | */ |
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107 | public ComplexFormat(String imaginaryCharacter, NumberFormat realFormat, |
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108 | NumberFormat imaginaryFormat) { |
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109 | 312 | super(); |
110 | 312 | setImaginaryCharacter(imaginaryCharacter); |
111 | 312 | setImaginaryFormat(imaginaryFormat); |
112 | 312 | setRealFormat(realFormat); |
113 | 312 | } |
114 | ||
115 | /** |
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116 | * This static method calls formatComplex() on a default instance of |
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117 | * ComplexFormat. |
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118 | * |
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119 | * @param c Complex object to format |
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120 | * @return A formatted number in the form "Re(c) + Im(c)i" |
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121 | */ |
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122 | public static String formatComplex( Complex c ) { |
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123 | 4 | return getInstance().format( c ); |
124 | } |
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125 | ||
126 | /** |
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127 | * Formats a {@link Complex} object to produce a string. |
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128 | * |
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129 | * @param complex the object to format. |
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130 | * @param toAppendTo where the text is to be appended |
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131 | * @param pos On input: an alignment field, if desired. On output: the |
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132 | * offsets of the alignment field |
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133 | * @return the value passed in as toAppendTo. |
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134 | */ |
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135 | public StringBuffer format(Complex complex, StringBuffer toAppendTo, |
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136 | FieldPosition pos) { |
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137 | ||
138 | 56 | pos.setBeginIndex(0); |
139 | 56 | pos.setEndIndex(0); |
140 | ||
141 | // format real |
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142 | 56 | double re = complex.getReal(); |
143 | 56 | formatDouble(re, getRealFormat(), toAppendTo, pos); |
144 | ||
145 | // format sign and imaginary |
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146 | 56 | double im = complex.getImaginary(); |
147 | 56 | if (im < 0.0) { |
148 | 20 | toAppendTo.append(" - "); |
149 | 20 | formatDouble(-im, getImaginaryFormat(), toAppendTo, pos); |
150 | 20 | toAppendTo.append(getImaginaryCharacter()); |
151 | 36 | } else if (im > 0.0 || Double.isNaN(im)) { |
152 | 28 | toAppendTo.append(" + "); |
153 | 28 | formatDouble(im, getImaginaryFormat(), toAppendTo, pos); |
154 | 28 | toAppendTo.append(getImaginaryCharacter()); |
155 | } |
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156 | ||
157 | 56 | return toAppendTo; |
158 | } |
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159 | ||
160 | /** |
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161 | * Formats a object to produce a string. <code>obj</code> must be either a |
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162 | * {@link Complex} object or a {@link Number} object. Any other type of |
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163 | * object will result in an {@link IllegalArgumentException} being thrown. |
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164 | * |
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165 | * @param obj the object to format. |
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166 | * @param toAppendTo where the text is to be appended |
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167 | * @param pos On input: an alignment field, if desired. On output: the |
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168 | * offsets of the alignment field |
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169 | * @return the value passed in as toAppendTo. |
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170 | * @see java.text.Format#format(java.lang.Object, java.lang.StringBuffer, java.text.FieldPosition) |
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171 | * @throws IllegalArgumentException is <code>obj</code> is not a valid type. |
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172 | */ |
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173 | public StringBuffer format(Object obj, StringBuffer toAppendTo, |
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174 | FieldPosition pos) { |
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175 | ||
176 | 60 | StringBuffer ret = null; |
177 | ||
178 | 60 | if (obj instanceof Complex) { |
179 | 52 | ret = format( (Complex)obj, toAppendTo, pos); |
180 | 8 | } else if (obj instanceof Number) { |
181 | 4 | ret = format( new Complex(((Number)obj).doubleValue(), 0.0), |
182 | toAppendTo, pos); |
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183 | } else { |
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184 | 4 | throw new IllegalArgumentException( |
185 | "Cannot format given Object as a Date"); |
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186 | } |
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187 | ||
188 | 56 | return ret; |
189 | } |
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190 | ||
191 | /** |
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192 | * Formats a double value to produce a string. In general, the value is |
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193 | * formatted using the formatting rules of <code>format</code>. There are |
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194 | * three exceptions to this: |
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195 | * <ol> |
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196 | * <li>NaN is formatted as '(NaN)'</li> |
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197 | * <li>Positive infinity is formatted as '(Infinity)'</li> |
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198 | * <li>Negative infinity is formatted as '(-Infinity)'</li> |
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199 | * </ol> |
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200 | * |
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201 | * @param value the double to format. |
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202 | * @param format the format used. |
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203 | * @param toAppendTo where the text is to be appended |
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204 | * @param pos On input: an alignment field, if desired. On output: the |
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205 | * offsets of the alignment field |
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206 | * @return the value passed in as toAppendTo. |
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207 | */ |
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208 | private StringBuffer formatDouble(double value, NumberFormat format, |
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209 | StringBuffer toAppendTo, FieldPosition pos) { |
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210 | 104 | if( Double.isNaN(value) || Double.isInfinite(value) ) { |
211 | 24 | toAppendTo.append('('); |
212 | 24 | toAppendTo.append(value); |
213 | 24 | toAppendTo.append(')'); |
214 | } else { |
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215 | 80 | getRealFormat().format(value, toAppendTo, pos); |
216 | } |
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217 | 104 | return toAppendTo; |
218 | } |
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219 | ||
220 | /** |
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221 | * Get the set of locales for which complex formats are available. This |
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222 | * is the same set as the {@link NumberFormat} set. |
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223 | * @return available complex format locales. |
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224 | */ |
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225 | public static Locale[] getAvailableLocales() { |
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226 | 0 | return NumberFormat.getAvailableLocales(); |
227 | } |
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228 | ||
229 | /** |
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230 | * Create a default number format. The default number format is based on |
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231 | * {@link NumberFormat#getInstance()} with the only customizing is the |
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232 | * maximum number of fraction digits, which is set to 2. |
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233 | * @return the default number format. |
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234 | */ |
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235 | private static NumberFormat getDefaultNumberFormat() { |
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236 | 28 | return getDefaultNumberFormat(Locale.getDefault()); |
237 | } |
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238 | ||
239 | /** |
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240 | * Create a default number format. The default number format is based on |
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241 | * {@link NumberFormat#getInstance(java.util.Locale)} with the only |
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242 | * customizing is the maximum number of fraction digits, which is set to 2. |
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243 | * @param locale the specific locale used by the format. |
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244 | * @return the default number format specific to the given locale. |
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245 | */ |
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246 | private static NumberFormat getDefaultNumberFormat(Locale locale) { |
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247 | 308 | NumberFormat nf = NumberFormat.getInstance(locale); |
248 | 308 | nf.setMaximumFractionDigits(2); |
249 | 308 | return nf; |
250 | } |
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251 | ||
252 | /** |
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253 | * Access the imaginaryCharacter. |
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254 | * @return the imaginaryCharacter. |
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255 | */ |
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256 | public String getImaginaryCharacter() { |
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257 | 136 | return imaginaryCharacter; |
258 | } |
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259 | ||
260 | /** |
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261 | * Access the imaginaryFormat. |
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262 | * @return the imaginaryFormat. |
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263 | */ |
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264 | public NumberFormat getImaginaryFormat() { |
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265 | 56 | return imaginaryFormat; |
266 | } |
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267 | ||
268 | /** |
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269 | * Returns the default complex format for the current locale. |
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270 | * @return the default complex format. |
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271 | */ |
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272 | public static ComplexFormat getInstance() { |
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273 | 4 | return getInstance(Locale.getDefault()); |
274 | } |
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275 | ||
276 | /** |
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277 | * Returns the default complex format for the given locale. |
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278 | * @param locale the specific locale used by the format. |
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279 | * @return the complex format specific to the given locale. |
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280 | */ |
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281 | public static ComplexFormat getInstance(Locale locale) { |
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282 | 280 | NumberFormat f = getDefaultNumberFormat(locale); |
283 | 280 | return new ComplexFormat(f); |
284 | } |
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285 | ||
286 | /** |
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287 | * Access the realFormat. |
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288 | * @return the realFormat. |
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289 | */ |
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290 | public NumberFormat getRealFormat() { |
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291 | 332 | return realFormat; |
292 | } |
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293 | ||
294 | /** |
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295 | * Parses a string to produce a {@link Complex} object. |
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296 | * |
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297 | * @param source the string to parse |
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298 | * @return the parsed {@link Complex} object. |
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299 | * @exception ParseException if the beginning of the specified string |
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300 | * cannot be parsed. |
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301 | */ |
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302 | public Complex parse(String source) throws ParseException { |
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303 | 0 | ParsePosition parsePosition = new ParsePosition(0); |
304 | 0 | Complex result = parse(source, parsePosition); |
305 | 0 | if (parsePosition.getIndex() == 0) { |
306 | 0 | throw new ParseException("Unparseable complex number: \"" + source + |
307 | "\"", parsePosition.getErrorIndex()); |
|
308 | } |
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309 | 0 | return result; |
310 | } |
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311 | ||
312 | /** |
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313 | * Parses a string to produce a {@link Complex} object. |
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314 | * |
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315 | * @param source the string to parse |
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316 | * @param pos input/ouput parsing parameter. |
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317 | * @return the parsed {@link Complex} object. |
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318 | */ |
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319 | public Complex parse(String source, ParsePosition pos) { |
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320 | 48 | int initialIndex = pos.getIndex(); |
321 | ||
322 | // parse whitespace |
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323 | 48 | parseAndIgnoreWhitespace(source, pos); |
324 | ||
325 | // parse real |
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326 | 48 | Number re = parseNumber(source, getRealFormat(), pos); |
327 | 48 | if (re == null) { |
328 | // invalid real number |
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329 | // set index back to initial, error index should already be set |
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330 | // character examined. |
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331 | 0 | pos.setIndex(initialIndex); |
332 | 0 | return null; |
333 | } |
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334 | ||
335 | // parse sign |
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336 | 48 | int startIndex = pos.getIndex(); |
337 | 48 | char c = parseNextCharacter(source, pos); |
338 | 48 | int sign = 0; |
339 | 48 | switch (c) { |
340 | case 0 : |
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341 | // no sign |
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342 | // return real only complex number |
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343 | 4 | return new Complex(re.doubleValue(), 0.0); |
344 | case '-' : |
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345 | 20 | sign = -1; |
346 | 20 | break; |
347 | case '+' : |
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348 | 24 | sign = 1; |
349 | 24 | break; |
350 | default : |
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351 | // invalid sign |
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352 | // set index back to initial, error index should be the last |
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353 | // character examined. |
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354 | 0 | pos.setIndex(initialIndex); |
355 | 0 | pos.setErrorIndex(startIndex); |
356 | 0 | return null; |
357 | } |
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358 | ||
359 | // parse whitespace |
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360 | 44 | parseAndIgnoreWhitespace(source, pos); |
361 | ||
362 | // parse imaginary |
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363 | 44 | Number im = parseNumber(source, getRealFormat(), pos); |
364 | 44 | if (im == null) { |
365 | // invalid imaginary number |
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366 | // set index back to initial, error index should already be set |
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367 | // character examined. |
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368 | 0 | pos.setIndex(initialIndex); |
369 | 0 | return null; |
370 | } |
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371 | ||
372 | // parse imaginary character |
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373 | 44 | int n = getImaginaryCharacter().length(); |
374 | 44 | startIndex = pos.getIndex(); |
375 | 44 | int endIndex = startIndex + n; |
376 | 44 | if (source.substring(startIndex, endIndex).compareTo( |
377 | getImaginaryCharacter()) != 0) { |
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378 | // set index back to initial, error index should be the start index |
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379 | // character examined. |
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380 | 0 | pos.setIndex(initialIndex); |
381 | 0 | pos.setErrorIndex(startIndex); |
382 | 0 | return null; |
383 | } |
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384 | 44 | pos.setIndex(endIndex); |
385 | ||
386 | 44 | return new Complex(re.doubleValue(), im.doubleValue() * sign); |
387 | } |
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388 | ||
389 | /** |
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390 | * Parses <code>source</code> until a non-whitespace character is found. |
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391 | * |
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392 | * @param source the string to parse |
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393 | * @param pos input/ouput parsing parameter. On output, <code>pos</code> |
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394 | * holds the index of the next non-whitespace character. |
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395 | */ |
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396 | private void parseAndIgnoreWhitespace(String source, ParsePosition pos) { |
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397 | 92 | parseNextCharacter(source, pos); |
398 | 92 | pos.setIndex(pos.getIndex() - 1); |
399 | 92 | } |
400 | ||
401 | /** |
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402 | * Parses <code>source</code> until a non-whitespace character is found. |
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403 | * |
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404 | * @param source the string to parse |
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405 | * @param pos input/ouput parsing parameter. |
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406 | * @return the first non-whitespace character. |
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407 | */ |
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408 | private char parseNextCharacter(String source, ParsePosition pos) { |
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409 | 140 | int index = pos.getIndex(); |
410 | 140 | int n = source.length(); |
411 | 140 | char ret = 0; |
412 | ||
413 | 140 | if (index < n) { |
414 | char c; |
|
415 | do { |
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416 | 224 | c = source.charAt(index++); |
417 | 224 | } while (Character.isWhitespace(c) && index < n); |
418 | 136 | pos.setIndex(index); |
419 | ||
420 | 136 | if (index < n) { |
421 | 136 | ret = c; |
422 | } |
|
423 | } |
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424 | ||
425 | 140 | return ret; |
426 | } |
|
427 | ||
428 | /** |
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429 | * Parses <code>source</code> for a special double values. These values |
|
430 | * include Double.NaN, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY. |
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431 | * |
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432 | * @param source the string to parse |
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433 | * @param value the special value to parse. |
|
434 | * @param pos input/ouput parsing parameter. |
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435 | * @return the special number. |
|
436 | */ |
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437 | private Number parseNumber(String source, double value, ParsePosition pos) { |
|
438 | 44 | Number ret = null; |
439 | ||
440 | 44 | StringBuffer sb = new StringBuffer(); |
441 | 44 | sb.append('('); |
442 | 44 | sb.append(value); |
443 | 44 | sb.append(')'); |
444 | ||
445 | 44 | int n = sb.length(); |
446 | 44 | int startIndex = pos.getIndex(); |
447 | 44 | int endIndex = startIndex + n; |
448 | 44 | if (endIndex < source.length()) { |
449 | 44 | if (source.substring(startIndex, endIndex).compareTo(sb.toString()) == 0) { |
450 | 24 | ret = new Double(value); |
451 | 24 | pos.setIndex(endIndex); |
452 | } |
|
453 | } |
|
454 | ||
455 | 44 | return ret; |
456 | } |
|
457 | ||
458 | /** |
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459 | * Parses <code>source</code> for a number. This method can parse normal, |
|
460 | * numeric values as well as special values. These special values include |
|
461 | * Double.NaN, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY. |
|
462 | * |
|
463 | * @param source the string to parse |
|
464 | * @param format the number format used to parse normal, numeric values. |
|
465 | * @param pos input/ouput parsing parameter. |
|
466 | * @return the parsed number. |
|
467 | */ |
|
468 | private Number parseNumber(String source, NumberFormat format, ParsePosition pos) { |
|
469 | 92 | int startIndex = pos.getIndex(); |
470 | 92 | Number number = getRealFormat().parse(source, pos); |
471 | 92 | int endIndex = pos.getIndex(); |
472 | ||
473 | // check for error parsing number |
|
474 | 92 | if (startIndex == endIndex) { |
475 | // try parsing special numbers |
|
476 | 24 | double[] special = {Double.NaN, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY}; |
477 | 44 | for (int i = 0; i < special.length; ++i) { |
478 | 44 | number = parseNumber(source, special[i], pos); |
479 | 44 | if (number != null) { |
480 | 24 | break; |
481 | } |
|
482 | } |
|
483 | } |
|
484 | ||
485 | 92 | return number; |
486 | } |
|
487 | ||
488 | /** |
|
489 | * Parses a string to produce a object. |
|
490 | * |
|
491 | * @param source the string to parse |
|
492 | * @param pos input/ouput parsing parameter. |
|
493 | * @return the parsed object. |
|
494 | * @see java.text.Format#parseObject(java.lang.String, java.text.ParsePosition) |
|
495 | */ |
|
496 | public Object parseObject(String source, ParsePosition pos) { |
|
497 | 48 | return parse(source, pos); |
498 | } |
|
499 | /** |
|
500 | * Modify the imaginaryCharacter. |
|
501 | * @param imaginaryCharacter The new imaginaryCharacter value. |
|
502 | * @throws IllegalArgumentException if <code>imaginaryCharacter</code> is |
|
503 | * <code>null</code> or an empty string. |
|
504 | */ |
|
505 | public void setImaginaryCharacter(String imaginaryCharacter) { |
|
506 | 456 | if (imaginaryCharacter == null || imaginaryCharacter.length() == 0) { |
507 | 8 | throw new IllegalArgumentException( |
508 | "imaginaryCharacter must be a non-empty string."); |
|
509 | } |
|
510 | 448 | this.imaginaryCharacter = imaginaryCharacter; |
511 | 448 | } |
512 | ||
513 | /** |
|
514 | * Modify the imaginaryFormat. |
|
515 | * @param imaginaryFormat The new imaginaryFormat value. |
|
516 | * @throws IllegalArgumentException if <code>imaginaryFormat</code> is |
|
517 | * <code>null</code>. |
|
518 | */ |
|
519 | public void setImaginaryFormat(NumberFormat imaginaryFormat) { |
|
520 | 320 | if (imaginaryFormat == null) { |
521 | 4 | throw new IllegalArgumentException( |
522 | "imaginaryFormat can not be null."); |
|
523 | } |
|
524 | 316 | this.imaginaryFormat = imaginaryFormat; |
525 | 316 | } |
526 | ||
527 | /** |
|
528 | * Modify the realFormat. |
|
529 | * @param realFormat The new realFormat value. |
|
530 | * @throws IllegalArgumentException if <code>realFormat</code> is |
|
531 | * <code>null</code>. |
|
532 | */ |
|
533 | public void setRealFormat(NumberFormat realFormat) { |
|
534 | 320 | if (realFormat == null) { |
535 | 4 | throw new IllegalArgumentException( |
536 | "realFormat can not be null."); |
|
537 | } |
|
538 | 316 | this.realFormat = realFormat; |
539 | 316 | } |
540 | } |