Raymond | dee0849 | 2015-04-02 10:43:13 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one or more |
| 3 | * contributor license agreements. See the NOTICE file distributed with |
| 4 | * this work for additional information regarding copyright ownership. |
| 5 | * The ASF licenses this file to You under the Apache License, Version 2.0 |
| 6 | * (the "License"); you may not use this file except in compliance with |
| 7 | * the License. You may obtain a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | */ |
| 17 | package org.apache.commons.math.stat; |
| 18 | |
| 19 | import java.io.Serializable; |
| 20 | import java.text.NumberFormat; |
| 21 | import java.util.Iterator; |
| 22 | import java.util.Comparator; |
| 23 | import java.util.TreeMap; |
| 24 | |
| 25 | import org.apache.commons.math.MathRuntimeException; |
| 26 | import org.apache.commons.math.exception.util.LocalizedFormats; |
| 27 | |
| 28 | /** |
| 29 | * Maintains a frequency distribution. |
| 30 | * <p> |
| 31 | * Accepts int, long, char or Comparable values. New values added must be |
| 32 | * comparable to those that have been added, otherwise the add method will |
| 33 | * throw an IllegalArgumentException.</p> |
| 34 | * <p> |
| 35 | * Integer values (int, long, Integer, Long) are not distinguished by type -- |
| 36 | * i.e. <code>addValue(Long.valueOf(2)), addValue(2), addValue(2l)</code> all have |
| 37 | * the same effect (similarly for arguments to <code>getCount,</code> etc.).</p> |
| 38 | * <p> |
| 39 | * char values are converted by <code>addValue</code> to Character instances. |
| 40 | * As such, these values are not comparable to integral values, so attempts |
| 41 | * to combine integral types with chars in a frequency distribution will fail. |
| 42 | * </p> |
| 43 | * <p> |
| 44 | * The values are ordered using the default (natural order), unless a |
| 45 | * <code>Comparator</code> is supplied in the constructor.</p> |
| 46 | * |
| 47 | * @version $Revision: 1054186 $ $Date: 2011-01-01 03:28:46 +0100 (sam. 01 janv. 2011) $ |
| 48 | */ |
| 49 | public class Frequency implements Serializable { |
| 50 | |
| 51 | /** Serializable version identifier */ |
| 52 | private static final long serialVersionUID = -3845586908418844111L; |
| 53 | |
| 54 | /** underlying collection */ |
| 55 | private final TreeMap<Comparable<?>, Long> freqTable; |
| 56 | |
| 57 | /** |
| 58 | * Default constructor. |
| 59 | */ |
| 60 | public Frequency() { |
| 61 | freqTable = new TreeMap<Comparable<?>, Long>(); |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * Constructor allowing values Comparator to be specified. |
| 66 | * |
| 67 | * @param comparator Comparator used to order values |
| 68 | */ |
| 69 | @SuppressWarnings("unchecked") // TODO is the cast OK? |
| 70 | public Frequency(Comparator<?> comparator) { |
| 71 | freqTable = new TreeMap<Comparable<?>, Long>((Comparator<? super Comparable<?>>) comparator); |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * Return a string representation of this frequency |
| 76 | * distribution. |
| 77 | * |
| 78 | * @return a string representation. |
| 79 | */ |
| 80 | @Override |
| 81 | public String toString() { |
| 82 | NumberFormat nf = NumberFormat.getPercentInstance(); |
| 83 | StringBuilder outBuffer = new StringBuilder(); |
| 84 | outBuffer.append("Value \t Freq. \t Pct. \t Cum Pct. \n"); |
| 85 | Iterator<Comparable<?>> iter = freqTable.keySet().iterator(); |
| 86 | while (iter.hasNext()) { |
| 87 | Comparable<?> value = iter.next(); |
| 88 | outBuffer.append(value); |
| 89 | outBuffer.append('\t'); |
| 90 | outBuffer.append(getCount(value)); |
| 91 | outBuffer.append('\t'); |
| 92 | outBuffer.append(nf.format(getPct(value))); |
| 93 | outBuffer.append('\t'); |
| 94 | outBuffer.append(nf.format(getCumPct(value))); |
| 95 | outBuffer.append('\n'); |
| 96 | } |
| 97 | return outBuffer.toString(); |
| 98 | } |
| 99 | |
| 100 | /** |
| 101 | * Adds 1 to the frequency count for v. |
| 102 | * <p> |
| 103 | * If other objects have already been added to this Frequency, v must |
| 104 | * be comparable to those that have already been added. |
| 105 | * </p> |
| 106 | * |
| 107 | * @param v the value to add. |
| 108 | * @throws IllegalArgumentException if <code>v</code> is not Comparable, |
| 109 | * or is not comparable with previous entries |
| 110 | * @deprecated use {@link #addValue(Comparable)} instead |
| 111 | */ |
| 112 | @Deprecated |
| 113 | public void addValue(Object v) { |
| 114 | if (v instanceof Comparable<?>){ |
| 115 | addValue((Comparable<?>) v); |
| 116 | } else { |
| 117 | throw MathRuntimeException.createIllegalArgumentException( |
| 118 | LocalizedFormats.CLASS_DOESNT_IMPLEMENT_COMPARABLE, |
| 119 | v.getClass().getName()); |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | /** |
| 124 | * Adds 1 to the frequency count for v. |
| 125 | * <p> |
| 126 | * If other objects have already been added to this Frequency, v must |
| 127 | * be comparable to those that have already been added. |
| 128 | * </p> |
| 129 | * |
| 130 | * @param v the value to add. |
| 131 | * @throws IllegalArgumentException if <code>v</code> is not comparable with previous entries |
| 132 | */ |
| 133 | public void addValue(Comparable<?> v){ |
| 134 | Comparable<?> obj = v; |
| 135 | if (v instanceof Integer) { |
| 136 | obj = Long.valueOf(((Integer) v).longValue()); |
| 137 | } |
| 138 | try { |
| 139 | Long count = freqTable.get(obj); |
| 140 | if (count == null) { |
| 141 | freqTable.put(obj, Long.valueOf(1)); |
| 142 | } else { |
| 143 | freqTable.put(obj, Long.valueOf(count.longValue() + 1)); |
| 144 | } |
| 145 | } catch (ClassCastException ex) { |
| 146 | //TreeMap will throw ClassCastException if v is not comparable |
| 147 | throw MathRuntimeException.createIllegalArgumentException( |
| 148 | LocalizedFormats.INSTANCES_NOT_COMPARABLE_TO_EXISTING_VALUES, |
| 149 | v.getClass().getName()); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * Adds 1 to the frequency count for v. |
| 155 | * |
| 156 | * @param v the value to add. |
| 157 | */ |
| 158 | public void addValue(int v) { |
| 159 | addValue(Long.valueOf(v)); |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * Adds 1 to the frequency count for v. |
| 164 | * |
| 165 | * @param v the value to add. |
| 166 | * @deprecated to be removed in math 3.0 |
| 167 | */ |
| 168 | @Deprecated |
| 169 | public void addValue(Integer v) { |
| 170 | addValue(Long.valueOf(v.longValue())); |
| 171 | } |
| 172 | |
| 173 | /** |
| 174 | * Adds 1 to the frequency count for v. |
| 175 | * |
| 176 | * @param v the value to add. |
| 177 | */ |
| 178 | public void addValue(long v) { |
| 179 | addValue(Long.valueOf(v)); |
| 180 | } |
| 181 | |
| 182 | /** |
| 183 | * Adds 1 to the frequency count for v. |
| 184 | * |
| 185 | * @param v the value to add. |
| 186 | */ |
| 187 | public void addValue(char v) { |
| 188 | addValue(Character.valueOf(v)); |
| 189 | } |
| 190 | |
| 191 | /** Clears the frequency table */ |
| 192 | public void clear() { |
| 193 | freqTable.clear(); |
| 194 | } |
| 195 | |
| 196 | /** |
| 197 | * Returns an Iterator over the set of values that have been added. |
| 198 | * <p> |
| 199 | * If added values are integral (i.e., integers, longs, Integers, or Longs), |
| 200 | * they are converted to Longs when they are added, so the objects returned |
| 201 | * by the Iterator will in this case be Longs.</p> |
| 202 | * |
| 203 | * @return values Iterator |
| 204 | */ |
| 205 | public Iterator<Comparable<?>> valuesIterator() { |
| 206 | return freqTable.keySet().iterator(); |
| 207 | } |
| 208 | |
| 209 | //------------------------------------------------------------------------- |
| 210 | |
| 211 | /** |
| 212 | * Returns the sum of all frequencies. |
| 213 | * |
| 214 | * @return the total frequency count. |
| 215 | */ |
| 216 | public long getSumFreq() { |
| 217 | long result = 0; |
| 218 | Iterator<Long> iterator = freqTable.values().iterator(); |
| 219 | while (iterator.hasNext()) { |
| 220 | result += iterator.next().longValue(); |
| 221 | } |
| 222 | return result; |
| 223 | } |
| 224 | |
| 225 | /** |
| 226 | * Returns the number of values = v. |
| 227 | * Returns 0 if the value is not comparable. |
| 228 | * |
| 229 | * @param v the value to lookup. |
| 230 | * @return the frequency of v. |
| 231 | * @deprecated replaced by {@link #getCount(Comparable)} as of 2.0 |
| 232 | */ |
| 233 | @Deprecated |
| 234 | public long getCount(Object v) { |
| 235 | return getCount((Comparable<?>) v); |
| 236 | } |
| 237 | |
| 238 | /** |
| 239 | * Returns the number of values = v. |
| 240 | * Returns 0 if the value is not comparable. |
| 241 | * |
| 242 | * @param v the value to lookup. |
| 243 | * @return the frequency of v. |
| 244 | */ |
| 245 | public long getCount(Comparable<?> v) { |
| 246 | if (v instanceof Integer) { |
| 247 | return getCount(((Integer) v).longValue()); |
| 248 | } |
| 249 | long result = 0; |
| 250 | try { |
| 251 | Long count = freqTable.get(v); |
| 252 | if (count != null) { |
| 253 | result = count.longValue(); |
| 254 | } |
| 255 | } catch (ClassCastException ex) { |
| 256 | // ignore and return 0 -- ClassCastException will be thrown if value is not comparable |
| 257 | } |
| 258 | return result; |
| 259 | } |
| 260 | |
| 261 | /** |
| 262 | * Returns the number of values = v. |
| 263 | * |
| 264 | * @param v the value to lookup. |
| 265 | * @return the frequency of v. |
| 266 | */ |
| 267 | public long getCount(int v) { |
| 268 | return getCount(Long.valueOf(v)); |
| 269 | } |
| 270 | |
| 271 | /** |
| 272 | * Returns the number of values = v. |
| 273 | * |
| 274 | * @param v the value to lookup. |
| 275 | * @return the frequency of v. |
| 276 | */ |
| 277 | public long getCount(long v) { |
| 278 | return getCount(Long.valueOf(v)); |
| 279 | } |
| 280 | |
| 281 | /** |
| 282 | * Returns the number of values = v. |
| 283 | * |
| 284 | * @param v the value to lookup. |
| 285 | * @return the frequency of v. |
| 286 | */ |
| 287 | public long getCount(char v) { |
| 288 | return getCount(Character.valueOf(v)); |
| 289 | } |
| 290 | |
| 291 | /** |
| 292 | * Returns the number of values in the frequency table. |
| 293 | * |
| 294 | * @return the number of unique values that have been added to the frequency table. |
| 295 | * @see #valuesIterator() |
| 296 | */ |
| 297 | public int getUniqueCount(){ |
| 298 | return freqTable.keySet().size(); |
| 299 | } |
| 300 | |
| 301 | //------------------------------------------------------------- |
| 302 | |
| 303 | /** |
| 304 | * Returns the percentage of values that are equal to v |
| 305 | * (as a proportion between 0 and 1). |
| 306 | * <p> |
| 307 | * Returns <code>Double.NaN</code> if no values have been added.</p> |
| 308 | * |
| 309 | * @param v the value to lookup |
| 310 | * @return the proportion of values equal to v |
| 311 | * @deprecated replaced by {@link #getPct(Comparable)} as of 2.0 |
| 312 | */ |
| 313 | @Deprecated |
| 314 | public double getPct(Object v) { |
| 315 | return getPct((Comparable<?>) v); |
| 316 | } |
| 317 | |
| 318 | /** |
| 319 | * Returns the percentage of values that are equal to v |
| 320 | * (as a proportion between 0 and 1). |
| 321 | * <p> |
| 322 | * Returns <code>Double.NaN</code> if no values have been added.</p> |
| 323 | * |
| 324 | * @param v the value to lookup |
| 325 | * @return the proportion of values equal to v |
| 326 | */ |
| 327 | public double getPct(Comparable<?> v) { |
| 328 | final long sumFreq = getSumFreq(); |
| 329 | if (sumFreq == 0) { |
| 330 | return Double.NaN; |
| 331 | } |
| 332 | return (double) getCount(v) / (double) sumFreq; |
| 333 | } |
| 334 | |
| 335 | /** |
| 336 | * Returns the percentage of values that are equal to v |
| 337 | * (as a proportion between 0 and 1). |
| 338 | * |
| 339 | * @param v the value to lookup |
| 340 | * @return the proportion of values equal to v |
| 341 | */ |
| 342 | public double getPct(int v) { |
| 343 | return getPct(Long.valueOf(v)); |
| 344 | } |
| 345 | |
| 346 | /** |
| 347 | * Returns the percentage of values that are equal to v |
| 348 | * (as a proportion between 0 and 1). |
| 349 | * |
| 350 | * @param v the value to lookup |
| 351 | * @return the proportion of values equal to v |
| 352 | */ |
| 353 | public double getPct(long v) { |
| 354 | return getPct(Long.valueOf(v)); |
| 355 | } |
| 356 | |
| 357 | /** |
| 358 | * Returns the percentage of values that are equal to v |
| 359 | * (as a proportion between 0 and 1). |
| 360 | * |
| 361 | * @param v the value to lookup |
| 362 | * @return the proportion of values equal to v |
| 363 | */ |
| 364 | public double getPct(char v) { |
| 365 | return getPct(Character.valueOf(v)); |
| 366 | } |
| 367 | |
| 368 | //----------------------------------------------------------------------------------------- |
| 369 | |
| 370 | /** |
| 371 | * Returns the cumulative frequency of values less than or equal to v. |
| 372 | * <p> |
| 373 | * Returns 0 if v is not comparable to the values set.</p> |
| 374 | * |
| 375 | * @param v the value to lookup. |
| 376 | * @return the proportion of values equal to v |
| 377 | * @deprecated replaced by {@link #getCumFreq(Comparable)} as of 2.0 |
| 378 | */ |
| 379 | @Deprecated |
| 380 | public long getCumFreq(Object v) { |
| 381 | return getCumFreq((Comparable<?>) v); |
| 382 | } |
| 383 | |
| 384 | /** |
| 385 | * Returns the cumulative frequency of values less than or equal to v. |
| 386 | * <p> |
| 387 | * Returns 0 if v is not comparable to the values set.</p> |
| 388 | * |
| 389 | * @param v the value to lookup. |
| 390 | * @return the proportion of values equal to v |
| 391 | */ |
| 392 | public long getCumFreq(Comparable<?> v) { |
| 393 | if (getSumFreq() == 0) { |
| 394 | return 0; |
| 395 | } |
| 396 | if (v instanceof Integer) { |
| 397 | return getCumFreq(((Integer) v).longValue()); |
| 398 | } |
| 399 | @SuppressWarnings("unchecked") // OK, freqTable is Comparable<?> |
| 400 | Comparator<Comparable<?>> c = (Comparator<Comparable<?>>) freqTable.comparator(); |
| 401 | if (c == null) { |
| 402 | c = new NaturalComparator(); |
| 403 | } |
| 404 | long result = 0; |
| 405 | |
| 406 | try { |
| 407 | Long value = freqTable.get(v); |
| 408 | if (value != null) { |
| 409 | result = value.longValue(); |
| 410 | } |
| 411 | } catch (ClassCastException ex) { |
| 412 | return result; // v is not comparable |
| 413 | } |
| 414 | |
| 415 | if (c.compare(v, freqTable.firstKey()) < 0) { |
| 416 | return 0; // v is comparable, but less than first value |
| 417 | } |
| 418 | |
| 419 | if (c.compare(v, freqTable.lastKey()) >= 0) { |
| 420 | return getSumFreq(); // v is comparable, but greater than the last value |
| 421 | } |
| 422 | |
| 423 | Iterator<Comparable<?>> values = valuesIterator(); |
| 424 | while (values.hasNext()) { |
| 425 | Comparable<?> nextValue = values.next(); |
| 426 | if (c.compare(v, nextValue) > 0) { |
| 427 | result += getCount(nextValue); |
| 428 | } else { |
| 429 | return result; |
| 430 | } |
| 431 | } |
| 432 | return result; |
| 433 | } |
| 434 | |
| 435 | /** |
| 436 | * Returns the cumulative frequency of values less than or equal to v. |
| 437 | * <p> |
| 438 | * Returns 0 if v is not comparable to the values set.</p> |
| 439 | * |
| 440 | * @param v the value to lookup |
| 441 | * @return the proportion of values equal to v |
| 442 | */ |
| 443 | public long getCumFreq(int v) { |
| 444 | return getCumFreq(Long.valueOf(v)); |
| 445 | } |
| 446 | |
| 447 | /** |
| 448 | * Returns the cumulative frequency of values less than or equal to v. |
| 449 | * <p> |
| 450 | * Returns 0 if v is not comparable to the values set.</p> |
| 451 | * |
| 452 | * @param v the value to lookup |
| 453 | * @return the proportion of values equal to v |
| 454 | */ |
| 455 | public long getCumFreq(long v) { |
| 456 | return getCumFreq(Long.valueOf(v)); |
| 457 | } |
| 458 | |
| 459 | /** |
| 460 | * Returns the cumulative frequency of values less than or equal to v. |
| 461 | * <p> |
| 462 | * Returns 0 if v is not comparable to the values set.</p> |
| 463 | * |
| 464 | * @param v the value to lookup |
| 465 | * @return the proportion of values equal to v |
| 466 | */ |
| 467 | public long getCumFreq(char v) { |
| 468 | return getCumFreq(Character.valueOf(v)); |
| 469 | } |
| 470 | |
| 471 | //---------------------------------------------------------------------------------------------- |
| 472 | |
| 473 | /** |
| 474 | * Returns the cumulative percentage of values less than or equal to v |
| 475 | * (as a proportion between 0 and 1). |
| 476 | * <p> |
| 477 | * Returns <code>Double.NaN</code> if no values have been added. |
| 478 | * Returns 0 if at least one value has been added, but v is not comparable |
| 479 | * to the values set.</p> |
| 480 | * |
| 481 | * @param v the value to lookup |
| 482 | * @return the proportion of values less than or equal to v |
| 483 | * @deprecated replaced by {@link #getCumPct(Comparable)} as of 2.0 |
| 484 | */ |
| 485 | @Deprecated |
| 486 | public double getCumPct(Object v) { |
| 487 | return getCumPct((Comparable<?>) v); |
| 488 | |
| 489 | } |
| 490 | |
| 491 | /** |
| 492 | * Returns the cumulative percentage of values less than or equal to v |
| 493 | * (as a proportion between 0 and 1). |
| 494 | * <p> |
| 495 | * Returns <code>Double.NaN</code> if no values have been added. |
| 496 | * Returns 0 if at least one value has been added, but v is not comparable |
| 497 | * to the values set.</p> |
| 498 | * |
| 499 | * @param v the value to lookup |
| 500 | * @return the proportion of values less than or equal to v |
| 501 | */ |
| 502 | public double getCumPct(Comparable<?> v) { |
| 503 | final long sumFreq = getSumFreq(); |
| 504 | if (sumFreq == 0) { |
| 505 | return Double.NaN; |
| 506 | } |
| 507 | return (double) getCumFreq(v) / (double) sumFreq; |
| 508 | } |
| 509 | |
| 510 | /** |
| 511 | * Returns the cumulative percentage of values less than or equal to v |
| 512 | * (as a proportion between 0 and 1). |
| 513 | * <p> |
| 514 | * Returns 0 if v is not comparable to the values set.</p> |
| 515 | * |
| 516 | * @param v the value to lookup |
| 517 | * @return the proportion of values less than or equal to v |
| 518 | */ |
| 519 | public double getCumPct(int v) { |
| 520 | return getCumPct(Long.valueOf(v)); |
| 521 | } |
| 522 | |
| 523 | /** |
| 524 | * Returns the cumulative percentage of values less than or equal to v |
| 525 | * (as a proportion between 0 and 1). |
| 526 | * <p> |
| 527 | * Returns 0 if v is not comparable to the values set.</p> |
| 528 | * |
| 529 | * @param v the value to lookup |
| 530 | * @return the proportion of values less than or equal to v |
| 531 | */ |
| 532 | public double getCumPct(long v) { |
| 533 | return getCumPct(Long.valueOf(v)); |
| 534 | } |
| 535 | |
| 536 | /** |
| 537 | * Returns the cumulative percentage of values less than or equal to v |
| 538 | * (as a proportion between 0 and 1). |
| 539 | * <p> |
| 540 | * Returns 0 if v is not comparable to the values set.</p> |
| 541 | * |
| 542 | * @param v the value to lookup |
| 543 | * @return the proportion of values less than or equal to v |
| 544 | */ |
| 545 | public double getCumPct(char v) { |
| 546 | return getCumPct(Character.valueOf(v)); |
| 547 | } |
| 548 | |
| 549 | /** |
| 550 | * A Comparator that compares comparable objects using the |
| 551 | * natural order. Copied from Commons Collections ComparableComparator. |
| 552 | */ |
| 553 | private static class NaturalComparator<T extends Comparable<T>> implements Comparator<Comparable<T>>, Serializable { |
| 554 | |
| 555 | /** Serializable version identifier */ |
| 556 | private static final long serialVersionUID = -3852193713161395148L; |
| 557 | |
| 558 | /** |
| 559 | * Compare the two {@link Comparable Comparable} arguments. |
| 560 | * This method is equivalent to: |
| 561 | * <pre>(({@link Comparable Comparable})o1).{@link Comparable#compareTo compareTo}(o2)</pre> |
| 562 | * |
| 563 | * @param o1 the first object |
| 564 | * @param o2 the second object |
| 565 | * @return result of comparison |
| 566 | * @throws NullPointerException when <i>o1</i> is <code>null</code>, |
| 567 | * or when <code>((Comparable)o1).compareTo(o2)</code> does |
| 568 | * @throws ClassCastException when <i>o1</i> is not a {@link Comparable Comparable}, |
| 569 | * or when <code>((Comparable)o1).compareTo(o2)</code> does |
| 570 | */ |
| 571 | @SuppressWarnings("unchecked") // cast to (T) may throw ClassCastException, see Javadoc |
| 572 | public int compare(Comparable<T> o1, Comparable<T> o2) { |
| 573 | return o1.compareTo((T) o2); |
| 574 | } |
| 575 | } |
| 576 | |
| 577 | /** {@inheritDoc} */ |
| 578 | @Override |
| 579 | public int hashCode() { |
| 580 | final int prime = 31; |
| 581 | int result = 1; |
| 582 | result = prime * result + |
| 583 | ((freqTable == null) ? 0 : freqTable.hashCode()); |
| 584 | return result; |
| 585 | } |
| 586 | |
| 587 | /** {@inheritDoc} */ |
| 588 | @Override |
| 589 | public boolean equals(Object obj) { |
| 590 | if (this == obj) |
| 591 | return true; |
| 592 | if (!(obj instanceof Frequency)) |
| 593 | return false; |
| 594 | Frequency other = (Frequency) obj; |
| 595 | if (freqTable == null) { |
| 596 | if (other.freqTable != null) |
| 597 | return false; |
| 598 | } else if (!freqTable.equals(other.freqTable)) |
| 599 | return false; |
| 600 | return true; |
| 601 | } |
| 602 | |
| 603 | } |