1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>comparable_distance</title> 5<link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../../index.html" title="Chapter 1. Geometry"> 8<link rel="up" href="../distance.html" title="distance"> 9<link rel="prev" href="comparable_distance_3_with_strategy.html" title="comparable_distance (with strategy)"> 10<link rel="next" href="distance_3_with_strategy.html" title="distance (with strategy)"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="comparable_distance_3_with_strategy.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../distance.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="distance_3_with_strategy.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="geometry.reference.algorithms.distance.comparable_distance_2"></a><a class="link" href="comparable_distance_2.html" title="comparable_distance">comparable_distance</a> 28</h5></div></div></div> 29<p> 30 <a class="indexterm" name="idm45635699553040"></a> 31Calculate the comparable distance measurement of two geometries. 32 </p> 33<h6> 34<a name="geometry.reference.algorithms.distance.comparable_distance_2.h0"></a> 35 <span class="phrase"><a name="geometry.reference.algorithms.distance.comparable_distance_2.description"></a></span><a class="link" href="comparable_distance_2.html#geometry.reference.algorithms.distance.comparable_distance_2.description">Description</a> 36 </h6> 37<p> 38 The free function comparable_distance does not necessarily calculate 39 the distance, but it calculates a distance measure such that two distances 40 are comparable to each other. For example: for the Cartesian coordinate 41 system, Pythagoras is used but the square root is not taken, which makes 42 it faster and the results of two point pairs can still be compared to 43 each other. 44 </p> 45<h6> 46<a name="geometry.reference.algorithms.distance.comparable_distance_2.h1"></a> 47 <span class="phrase"><a name="geometry.reference.algorithms.distance.comparable_distance_2.synopsis"></a></span><a class="link" href="comparable_distance_2.html#geometry.reference.algorithms.distance.comparable_distance_2.synopsis">Synopsis</a> 48 </h6> 49<p> 50</p> 51<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Geometry1</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Geometry2</span><span class="special">></span> 52<span class="identifier">default_comparable_distance_result</span><span class="special"><</span><span class="identifier">Geometry1</span><span class="special">,</span> <span class="identifier">Geometry2</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">comparable_distance</span><span class="special">(</span><span class="identifier">Geometry1</span> <span class="keyword">const</span> <span class="special">&</span> <span class="identifier">geometry1</span><span class="special">,</span> <span class="identifier">Geometry2</span> <span class="keyword">const</span> <span class="special">&</span> <span class="identifier">geometry2</span><span class="special">)</span></pre> 53<p> 54 </p> 55<h6> 56<a name="geometry.reference.algorithms.distance.comparable_distance_2.h2"></a> 57 <span class="phrase"><a name="geometry.reference.algorithms.distance.comparable_distance_2.parameters"></a></span><a class="link" href="comparable_distance_2.html#geometry.reference.algorithms.distance.comparable_distance_2.parameters">Parameters</a> 58 </h6> 59<div class="informaltable"><table class="table"> 60<colgroup> 61<col> 62<col> 63<col> 64<col> 65</colgroup> 66<thead><tr> 67<th> 68 <p> 69 Type 70 </p> 71 </th> 72<th> 73 <p> 74 Concept 75 </p> 76 </th> 77<th> 78 <p> 79 Name 80 </p> 81 </th> 82<th> 83 <p> 84 Description 85 </p> 86 </th> 87</tr></thead> 88<tbody> 89<tr> 90<td> 91 <p> 92 Geometry1 const & 93 </p> 94 </td> 95<td> 96 <p> 97 first geometry type 98 </p> 99 </td> 100<td> 101 <p> 102 geometry1 103 </p> 104 </td> 105<td> 106 <p> 107 A model of the specified concept 108 </p> 109 </td> 110</tr> 111<tr> 112<td> 113 <p> 114 Geometry2 const & 115 </p> 116 </td> 117<td> 118 <p> 119 second geometry type 120 </p> 121 </td> 122<td> 123 <p> 124 geometry2 125 </p> 126 </td> 127<td> 128 <p> 129 A model of the specified concept 130 </p> 131 </td> 132</tr> 133</tbody> 134</table></div> 135<h6> 136<a name="geometry.reference.algorithms.distance.comparable_distance_2.h3"></a> 137 <span class="phrase"><a name="geometry.reference.algorithms.distance.comparable_distance_2.returns"></a></span><a class="link" href="comparable_distance_2.html#geometry.reference.algorithms.distance.comparable_distance_2.returns">Returns</a> 138 </h6> 139<p> 140 The calculated comparable distance 141 </p> 142<h6> 143<a name="geometry.reference.algorithms.distance.comparable_distance_2.h4"></a> 144 <span class="phrase"><a name="geometry.reference.algorithms.distance.comparable_distance_2.header"></a></span><a class="link" href="comparable_distance_2.html#geometry.reference.algorithms.distance.comparable_distance_2.header">Header</a> 145 </h6> 146<p> 147 Either 148 </p> 149<p> 150 <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 151 </p> 152<p> 153 Or 154 </p> 155<p> 156 <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">algorithms</span><span class="special">/</span><span class="identifier">comparable_distance</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 157 </p> 158<h6> 159<a name="geometry.reference.algorithms.distance.comparable_distance_2.h5"></a> 160 <span class="phrase"><a name="geometry.reference.algorithms.distance.comparable_distance_2.conformance"></a></span><a class="link" href="comparable_distance_2.html#geometry.reference.algorithms.distance.comparable_distance_2.conformance">Conformance</a> 161 </h6> 162<p> 163 The function comparable_distance is not defined by OGC. 164 </p> 165<h6> 166<a name="geometry.reference.algorithms.distance.comparable_distance_2.h6"></a> 167 <span class="phrase"><a name="geometry.reference.algorithms.distance.comparable_distance_2.behaviour"></a></span><a class="link" href="comparable_distance_2.html#geometry.reference.algorithms.distance.comparable_distance_2.behaviour">Behaviour</a> 168 </h6> 169<p> 170 It depends on the coordinate system of the geometry's point type if there 171 is a strategy available which can determine (more efficient than the 172 standard strategy) a measure of comparable distance. 173 </p> 174<h6> 175<a name="geometry.reference.algorithms.distance.comparable_distance_2.h7"></a> 176 <span class="phrase"><a name="geometry.reference.algorithms.distance.comparable_distance_2.supported_geometries"></a></span><a class="link" href="comparable_distance_2.html#geometry.reference.algorithms.distance.comparable_distance_2.supported_geometries">Supported 177 geometries</a> 178 </h6> 179<div class="informaltable"><table class="table"> 180<colgroup> 181<col> 182<col> 183<col> 184<col> 185<col> 186<col> 187<col> 188<col> 189<col> 190<col> 191<col> 192</colgroup> 193<thead><tr> 194<th> 195 </th> 196<th> 197 <p> 198 Point 199 </p> 200 </th> 201<th> 202 <p> 203 Segment 204 </p> 205 </th> 206<th> 207 <p> 208 Box 209 </p> 210 </th> 211<th> 212 <p> 213 Linestring 214 </p> 215 </th> 216<th> 217 <p> 218 Ring 219 </p> 220 </th> 221<th> 222 <p> 223 Polygon 224 </p> 225 </th> 226<th> 227 <p> 228 MultiPoint 229 </p> 230 </th> 231<th> 232 <p> 233 MultiLinestring 234 </p> 235 </th> 236<th> 237 <p> 238 MultiPolygon 239 </p> 240 </th> 241<th> 242 <p> 243 Variant 244 </p> 245 </th> 246</tr></thead> 247<tbody> 248<tr> 249<td> 250 <p> 251 Point 252 </p> 253 </td> 254<td> 255 <p> 256 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 257 </p> 258 </td> 259<td> 260 <p> 261 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 262 </p> 263 </td> 264<td> 265 <p> 266 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 267 </p> 268 </td> 269<td> 270 <p> 271 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 272 </p> 273 </td> 274<td> 275 <p> 276 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 277 </p> 278 </td> 279<td> 280 <p> 281 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 282 </p> 283 </td> 284<td> 285 <p> 286 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 287 </p> 288 </td> 289<td> 290 <p> 291 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 292 </p> 293 </td> 294<td> 295 <p> 296 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 297 </p> 298 </td> 299<td> 300 <p> 301 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 302 </p> 303 </td> 304</tr> 305<tr> 306<td> 307 <p> 308 Segment 309 </p> 310 </td> 311<td> 312 <p> 313 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 314 </p> 315 </td> 316<td> 317 <p> 318 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 319 </p> 320 </td> 321<td> 322 <p> 323 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 324 </p> 325 </td> 326<td> 327 <p> 328 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 329 </p> 330 </td> 331<td> 332 <p> 333 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 334 </p> 335 </td> 336<td> 337 <p> 338 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 339 </p> 340 </td> 341<td> 342 <p> 343 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 344 </p> 345 </td> 346<td> 347 <p> 348 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 349 </p> 350 </td> 351<td> 352 <p> 353 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 354 </p> 355 </td> 356<td> 357 <p> 358 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 359 </p> 360 </td> 361</tr> 362<tr> 363<td> 364 <p> 365 Box 366 </p> 367 </td> 368<td> 369 <p> 370 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 371 </p> 372 </td> 373<td> 374 <p> 375 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 376 </p> 377 </td> 378<td> 379 <p> 380 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 381 </p> 382 </td> 383<td> 384 <p> 385 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 386 </p> 387 </td> 388<td> 389 <p> 390 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 391 </p> 392 </td> 393<td> 394 <p> 395 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 396 </p> 397 </td> 398<td> 399 <p> 400 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 401 </p> 402 </td> 403<td> 404 <p> 405 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 406 </p> 407 </td> 408<td> 409 <p> 410 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 411 </p> 412 </td> 413<td> 414 <p> 415 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 416 </p> 417 </td> 418</tr> 419<tr> 420<td> 421 <p> 422 Linestring 423 </p> 424 </td> 425<td> 426 <p> 427 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 428 </p> 429 </td> 430<td> 431 <p> 432 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 433 </p> 434 </td> 435<td> 436 <p> 437 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 438 </p> 439 </td> 440<td> 441 <p> 442 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 443 </p> 444 </td> 445<td> 446 <p> 447 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 448 </p> 449 </td> 450<td> 451 <p> 452 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 453 </p> 454 </td> 455<td> 456 <p> 457 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 458 </p> 459 </td> 460<td> 461 <p> 462 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 463 </p> 464 </td> 465<td> 466 <p> 467 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 468 </p> 469 </td> 470<td> 471 <p> 472 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 473 </p> 474 </td> 475</tr> 476<tr> 477<td> 478 <p> 479 Ring 480 </p> 481 </td> 482<td> 483 <p> 484 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 485 </p> 486 </td> 487<td> 488 <p> 489 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 490 </p> 491 </td> 492<td> 493 <p> 494 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 495 </p> 496 </td> 497<td> 498 <p> 499 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 500 </p> 501 </td> 502<td> 503 <p> 504 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 505 </p> 506 </td> 507<td> 508 <p> 509 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 510 </p> 511 </td> 512<td> 513 <p> 514 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 515 </p> 516 </td> 517<td> 518 <p> 519 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 520 </p> 521 </td> 522<td> 523 <p> 524 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 525 </p> 526 </td> 527<td> 528 <p> 529 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 530 </p> 531 </td> 532</tr> 533<tr> 534<td> 535 <p> 536 Polygon 537 </p> 538 </td> 539<td> 540 <p> 541 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 542 </p> 543 </td> 544<td> 545 <p> 546 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 547 </p> 548 </td> 549<td> 550 <p> 551 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 552 </p> 553 </td> 554<td> 555 <p> 556 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 557 </p> 558 </td> 559<td> 560 <p> 561 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 562 </p> 563 </td> 564<td> 565 <p> 566 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 567 </p> 568 </td> 569<td> 570 <p> 571 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 572 </p> 573 </td> 574<td> 575 <p> 576 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 577 </p> 578 </td> 579<td> 580 <p> 581 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 582 </p> 583 </td> 584<td> 585 <p> 586 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 587 </p> 588 </td> 589</tr> 590<tr> 591<td> 592 <p> 593 MultiPoint 594 </p> 595 </td> 596<td> 597 <p> 598 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 599 </p> 600 </td> 601<td> 602 <p> 603 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 604 </p> 605 </td> 606<td> 607 <p> 608 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 609 </p> 610 </td> 611<td> 612 <p> 613 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 614 </p> 615 </td> 616<td> 617 <p> 618 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 619 </p> 620 </td> 621<td> 622 <p> 623 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 624 </p> 625 </td> 626<td> 627 <p> 628 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 629 </p> 630 </td> 631<td> 632 <p> 633 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 634 </p> 635 </td> 636<td> 637 <p> 638 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 639 </p> 640 </td> 641<td> 642 <p> 643 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 644 </p> 645 </td> 646</tr> 647<tr> 648<td> 649 <p> 650 MultiLinestring 651 </p> 652 </td> 653<td> 654 <p> 655 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 656 </p> 657 </td> 658<td> 659 <p> 660 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 661 </p> 662 </td> 663<td> 664 <p> 665 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 666 </p> 667 </td> 668<td> 669 <p> 670 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 671 </p> 672 </td> 673<td> 674 <p> 675 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 676 </p> 677 </td> 678<td> 679 <p> 680 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 681 </p> 682 </td> 683<td> 684 <p> 685 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 686 </p> 687 </td> 688<td> 689 <p> 690 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 691 </p> 692 </td> 693<td> 694 <p> 695 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 696 </p> 697 </td> 698<td> 699 <p> 700 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 701 </p> 702 </td> 703</tr> 704<tr> 705<td> 706 <p> 707 MultiPolygon 708 </p> 709 </td> 710<td> 711 <p> 712 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 713 </p> 714 </td> 715<td> 716 <p> 717 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 718 </p> 719 </td> 720<td> 721 <p> 722 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 723 </p> 724 </td> 725<td> 726 <p> 727 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 728 </p> 729 </td> 730<td> 731 <p> 732 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 733 </p> 734 </td> 735<td> 736 <p> 737 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 738 </p> 739 </td> 740<td> 741 <p> 742 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 743 </p> 744 </td> 745<td> 746 <p> 747 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 748 </p> 749 </td> 750<td> 751 <p> 752 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 753 </p> 754 </td> 755<td> 756 <p> 757 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 758 </p> 759 </td> 760</tr> 761<tr> 762<td> 763 <p> 764 Variant 765 </p> 766 </td> 767<td> 768 <p> 769 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 770 </p> 771 </td> 772<td> 773 <p> 774 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 775 </p> 776 </td> 777<td> 778 <p> 779 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 780 </p> 781 </td> 782<td> 783 <p> 784 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 785 </p> 786 </td> 787<td> 788 <p> 789 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 790 </p> 791 </td> 792<td> 793 <p> 794 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 795 </p> 796 </td> 797<td> 798 <p> 799 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 800 </p> 801 </td> 802<td> 803 <p> 804 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 805 </p> 806 </td> 807<td> 808 <p> 809 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 810 </p> 811 </td> 812<td> 813 <p> 814 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 815 </p> 816 </td> 817</tr> 818</tbody> 819</table></div> 820<h6> 821<a name="geometry.reference.algorithms.distance.comparable_distance_2.h8"></a> 822 <span class="phrase"><a name="geometry.reference.algorithms.distance.comparable_distance_2.complexity"></a></span><a class="link" href="comparable_distance_2.html#geometry.reference.algorithms.distance.comparable_distance_2.complexity">Complexity</a> 823 </h6> 824<p> 825 For point to geometry: linear 826 </p> 827<p> 828 For multi-point to ring/polygon/multi-polygon: currently quadratic 829 </p> 830<p> 831 For all other geometry combinations: linearithmic 832 </p> 833<h6> 834<a name="geometry.reference.algorithms.distance.comparable_distance_2.h9"></a> 835 <span class="phrase"><a name="geometry.reference.algorithms.distance.comparable_distance_2.example"></a></span><a class="link" href="comparable_distance_2.html#geometry.reference.algorithms.distance.comparable_distance_2.example">Example</a> 836 </h6> 837<p> 838 Shows how to efficiently get the closest point 839 </p> 840<p> 841</p> 842<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> 843 844<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 845<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">point_xy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 846 847<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">numeric</span><span class="special">/</span><span class="identifier">conversion</span><span class="special">/</span><span class="identifier">bounds</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 848<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">foreach</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 849 850<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> 851<span class="special">{</span> 852 <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">d2</span><span class="special">::</span><span class="identifier">point_xy</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">point_type</span><span class="special">;</span> 853 854 <span class="identifier">point_type</span> <span class="identifier">p</span><span class="special">(</span><span class="number">1.4</span><span class="special">,</span> <span class="number">2.6</span><span class="special">);</span> 855 856 <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="identifier">point_type</span><span class="special">></span> <span class="identifier">v</span><span class="special">;</span> 857 <span class="keyword">for</span> <span class="special">(</span><span class="keyword">double</span> <span class="identifier">x</span> <span class="special">=</span> <span class="number">0.0</span><span class="special">;</span> <span class="identifier">x</span> <span class="special"><=</span> <span class="number">4.0</span><span class="special">;</span> <span class="identifier">x</span><span class="special">++)</span> 858 <span class="special">{</span> 859 <span class="keyword">for</span> <span class="special">(</span><span class="keyword">double</span> <span class="identifier">y</span> <span class="special">=</span> <span class="number">0.0</span><span class="special">;</span> <span class="identifier">y</span> <span class="special"><=</span> <span class="number">4.0</span><span class="special">;</span> <span class="identifier">y</span><span class="special">++)</span> 860 <span class="special">{</span> 861 <span class="identifier">v</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">point_type</span><span class="special">(</span><span class="identifier">x</span><span class="special">,</span> <span class="identifier">y</span><span class="special">));</span> 862 <span class="special">}</span> 863 <span class="special">}</span> 864 865 <span class="identifier">point_type</span> <span class="identifier">min_p</span><span class="special">;</span> 866 <span class="keyword">double</span> <span class="identifier">min_d</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">numeric</span><span class="special">::</span><span class="identifier">bounds</span><span class="special"><</span><span class="keyword">double</span><span class="special">>::</span><span class="identifier">highest</span><span class="special">();</span> 867 <span class="identifier">BOOST_FOREACH</span><span class="special">(</span><span class="identifier">point_type</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">pv</span><span class="special">,</span> <span class="identifier">v</span><span class="special">)</span> 868 <span class="special">{</span> 869 <span class="keyword">double</span> <span class="identifier">d</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">comparable_distance</span><span class="special">(</span><span class="identifier">p</span><span class="special">,</span> <span class="identifier">pv</span><span class="special">);</span> 870 <span class="keyword">if</span> <span class="special">(</span><span class="identifier">d</span> <span class="special"><</span> <span class="identifier">min_d</span><span class="special">)</span> 871 <span class="special">{</span> 872 <span class="identifier">min_d</span> <span class="special">=</span> <span class="identifier">d</span><span class="special">;</span> 873 <span class="identifier">min_p</span> <span class="special">=</span> <span class="identifier">pv</span><span class="special">;</span> 874 <span class="special">}</span> 875 <span class="special">}</span> 876 877 <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> 878 <span class="special"><<</span> <span class="string">"Closest: "</span> <span class="special"><<</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">dsv</span><span class="special">(</span><span class="identifier">min_p</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span> 879 <span class="special"><<</span> <span class="string">"At: "</span> <span class="special"><<</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">distance</span><span class="special">(</span><span class="identifier">p</span><span class="special">,</span> <span class="identifier">min_p</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> 880 881 <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> 882<span class="special">}</span> 883</pre> 884<p> 885 </p> 886<p> 887 Output: 888 </p> 889<pre class="programlisting">Closest: (1, 3) 890At: 0.565685 891</pre> 892</div> 893<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 894<td align="left"></td> 895<td align="right"><div class="copyright-footer">Copyright © 2009-2019 Barend Gehrels, Bruno Lalande, Mateusz Loskot, Adam 896 Wulkiewicz, Oracle and/or its affiliates<p> 897 Distributed under the Boost Software License, Version 1.0. (See accompanying 898 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 899 </p> 900</div></td> 901</tr></table> 902<hr> 903<div class="spirit-nav"> 904<a accesskey="p" href="comparable_distance_3_with_strategy.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../distance.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="distance_3_with_strategy.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 905</div> 906</body> 907</html> 908
