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Relaxation (iterative method)

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580: 852: 98:, in which the solution-function's values are specified on boundary of a domain; the problem is to compute a solution also on its interior. Relaxation methods are used to solve the linear equations resulting from a discretization of the differential equation, for example by finite differences. 308: 335: 868:
While the method converges under general conditions, it typically makes slower progress than competing methods. Nonetheless, the study of relaxation methods remains a core part of linear algebra, because the transformations of relaxation theory provide excellent
634:, the relaxation method assigns the given values of function φ to the grid points near the boundary and arbitrary values to the interior grid points, and then repeatedly performs the assignment φ := φ* on the interior points, where φ* is defined by: 640: 141: 1146:. Egon Balas (foreword) (Translated by Steven Vajda from the (1983 Paris: Dunod) French ed.). Chichester: A Wiley-Interscience Publication. John Wiley & Sons, Ltd. pp. xxviii+489. 575:{\displaystyle \varphi (x,y)={\tfrac {1}{4}}\left(\varphi (x{+}h,y)+\varphi (x,y{+}h)+\varphi (x{-}h,y)+\varphi (x,y{-}h)\,-\,h^{2}{\nabla }^{2}\varphi (x,y)\right)\,+\,{\mathcal {O}}(h^{4})\,.} 1058:(1983). "16 Iterative methods for linear inequalities and linear programs (especially 16.2 Relaxation methods, and 16.4 Sparsity-preserving iterative SOR algorithms for linear programming)". 1256:. Classics in Applied Mathematics. Vol. 30 (Reprint of the 1970 Academic Press ed.). Philadelphia, PA: Society for Industrial and Applied Mathematics (SIAM). pp. xxvi+572. 953:. Classics in Applied Mathematics. Vol. 30 (Reprint of the 1970 Academic Press ed.). Philadelphia, PA: Society for Industrial and Applied Mathematics (SIAM). pp. xxvi+572. 625: 1213: 847:{\displaystyle \varphi ^{*}(x,y)={\tfrac {1}{4}}\left(\varphi (x{+}h,y)+\varphi (x,y{+}h)+\varphi (x{-}h,y)+\varphi (x,y{-}h)\,-\,h^{2}f(x,y)\right)\,,} 1455: 303:{\displaystyle {\frac {d^{2}\varphi (x)}{{dx}^{2}}}={\frac {\varphi (x{-}h)-2\varphi (x)+\varphi (x{+}h)}{h^{2}}}\,+\,{\mathcal {O}}(h^{2})\,.} 83: 1429: 1292: 1204: 1093: 72: 1450: 1414: 1399: 1363: 1261: 1245: 1221: 1151: 1067: 1042: 958: 121:
a difficult problem by a simpler problem whose "relaxed" solution provides information about the solution of the original problem.
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values for the other grid points as the initial assignment. This can then also be done recursively for the coarser computation.
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may be used to accelerate the methods. One can first compute an approximation on a coarser grid – usually the double spacing 2
109:, it resembles repeated application of a local smoothing filter to the solution vector. These are not to be confused with 28: 1445: 921: 873:
for new methods. Indeed, the choice of preconditioner is often more important than the choice of iterative method.
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Advances in Imaging and Electron Physics, Vol. 116, Numerical Field Calculation for Charged Particle Optics
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When φ is a smooth real-valued function on the real numbers, its second derivative can be approximated by:
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This article is about iterative methods for solving systems of equations. For other uses, see
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Relaxation methods are important especially in the solution of linear systems used to model
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Goffin, J.-L. (1980). "The relaxation method for solving systems of linear inequalities".
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can be applied to either of the Jacobi and Gauss–Seidel methods to speed convergence.
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problems and also for systems of linear inequalities, such as those arising in
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Using this in both dimensions for a function φ of two arguments at the point (
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William L. Briggs, Van Emden Henson, and Steve F. McCormick (2000),
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In linear systems, the two main classes of relaxation methods are
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The method is easily generalized to other numbers of dimensions.
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Press, WH; Teukolsky, SA; Vetterling, WT; Flannery, BP (2007).
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Iterative solution of nonlinear equations in several variables
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Iterative solution of nonlinear equations in several variables
71:. They are also used for the solution of linear equations for 547: 275: 1062:. New York: John Wiley & Sons Inc. pp. 453–464. 630:
numerically on a two-dimensional grid with grid spacing
1168:. Editions Tec & Doc, Paris, 2008. xxx+711 pp. . ). 1287:(3rd ed.). New York: Cambridge University Press. 673: 361: 643: 594: 585:
To approximate the solution of the Poisson equation:
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Iterative relaxation of solutions is commonly dubbed
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Relaxation methods were developed for solving large
1329:, Academic Press, 1971. (reprinted by Dover, 2003) 1285:Numerical Recipes: The Art of Scientific Computing 1166:Programmation mathĂ©matique: ThĂ©orie et algorithmes 1017:, Academic Press, 1971. (reprinted by Dover, 2003) 944: 942: 846: 619: 574: 302: 1238:Nonnegative Matrices in the Mathematical Sciences 1035:Nonnegative Matrices in the Mathematical Sciences 1144:Mathematical programming: Theory and algorithms 1214:Society for Industrial and Applied Mathematics 8: 1384:Numerical Analysis of Electromagnetic Fields 1307:Iterative Methods for Sparse Linear Systems 1187:Iterative Methods for Sparse Linear Systems 1390:P. Grivet, P.W. Hawkes, A.Septier (1972). 1327:Iterative Solution of Large Linear Systems 1015:Iterative Solution of Large Linear Systems 1348:Relaxation Methods in Theoretical Physics 1341:Relaxation Methods in Engineering Science 1252:Ortega, J. M.; Rheinboldt, W. C. (2000). 949:Ortega, J. M.; Rheinboldt, W. C. (2000). 918:is an improvement upon the Jacobi method. 840: 811: 806: 802: 791: 756: 733: 698: 672: 648: 642: 620:{\displaystyle {\nabla }^{2}\varphi =f\,} 616: 601: 596: 593: 568: 559: 546: 545: 544: 540: 511: 506: 499: 494: 490: 479: 444: 421: 386: 360: 337: 296: 287: 274: 273: 272: 268: 260: 244: 203: 191: 180: 172: 152: 145: 143: 1375:Numerical Techniques in Electromagnetics 1134: 1132: 105:because with certain equations, such as 1407:Electrostatic Lens Systems, 2nd edition 1007: 1005: 1003: 1001: 984: 982: 980: 978: 938: 84:elliptic partial differential equations 1177: 1175: 7: 1236:Abraham Berman, Robert J. Plemmons, 1025: 1023: 1350:. Oxford University Press, Oxford. 1343:. Oxford University Press, Oxford. 1281:"Section 18.3. Relaxation Methods" 1094:Mathematics of Operations Research 597: 507: 25: 125:Model problem of potential theory 1164:. (2008 Second ed., in French: 50:, including nonlinear systems. 1456:Relaxation (iterative methods) 911:is a simple relaxation method. 832: 820: 799: 779: 770: 750: 741: 721: 712: 692: 666: 654: 565: 552: 532: 520: 487: 467: 458: 438: 429: 409: 400: 380: 354: 342: 293: 280: 252: 238: 229: 223: 211: 197: 167: 161: 1: 883:– and use that solution with 1392:Electron Optics, 2nd edition 898:stationary iterative methods 864:Convergence and acceleration 94:. These equations describe 29:Relaxation (disambiguation) 1472: 922:Successive over-relaxation 128: 26: 1356:Classical Electrodynamics 1354:John. D. Jackson (1999). 1318:Matrix Iterative Analysis 1310:, 1st edition, PWS, 1996. 1212:(2nd ed.), Philadelphia: 1190:, 1st edition, PWS, 1996. 993:Matrix Iterative Analysis 131:Discrete Poisson equation 115:mathematical optimization 1451:Numerical linear algebra 1405:D. W. O. Heddle (2000). 90:and its generalization, 1377:. Boca Raton: CRC Pres. 1346:Southwell, R.V. (1946) 1339:Southwell, R.V. (1940) 902:Krylov subspace methods 900:, and the more general 96:boundary-value problems 1373:M.N.O. Sadiku (1992). 848: 621: 576: 304: 69:differential equations 1420:Erwin Kasper (2001). 1386:. New York: Springer. 1358:. New Jersey: Wiley. 849: 622: 577: 321:), and solving for φ( 305: 36:numerical mathematics 1202:A Multigrid Tutorial 1107:10.1287/moor.5.3.388 1056:Murty, Katta G. 641: 592: 336: 142: 73:linear least-squares 48:systems of equations 1382:P.-B. Zhou (1993). 1324:David M. Young, Jr. 1012:David M. Young, Jr. 916:Gauss–Seidel method 857:until convergence. 1424:. Academic Press. 1394:. Pergamon Press. 1207:2006-10-06 at the 1060:Linear programming 1031:Robert J. Plemmons 844: 682: 617: 572: 370: 300: 107:Laplace's equation 92:Poisson's equation 88:Laplace's equation 77:linear programming 40:relaxation methods 1446:Iterative methods 1430:978-0-12-014758-8 1294:978-0-521-88068-8 928:Multigrid methods 877:Multigrid methods 681: 369: 266: 186: 62:finite-difference 60:, which arose as 44:iterative methods 18:Relaxation method 16:(Redirected from 1463: 1387: 1378: 1369: 1314:Richard S. Varga 1298: 1275: 1225: 1197: 1191: 1179: 1170: 1169: 1136: 1127: 1126: 1088: 1082: 1081: 1052: 1046: 1029:Abraham Berman, 1027: 1018: 1009: 996: 989:Richard S. Varga 986: 973: 972: 946: 853: 851: 850: 845: 839: 835: 816: 815: 795: 760: 737: 702: 683: 674: 653: 652: 626: 624: 623: 618: 606: 605: 600: 581: 579: 578: 573: 564: 563: 551: 550: 539: 535: 516: 515: 510: 504: 503: 483: 448: 425: 390: 371: 362: 309: 307: 306: 301: 292: 291: 279: 278: 267: 265: 264: 255: 248: 207: 192: 187: 185: 184: 179: 170: 157: 156: 146: 21: 1471: 1470: 1466: 1465: 1464: 1462: 1461: 1460: 1436: 1435: 1381: 1372: 1366: 1353: 1336: 1334:Further reading 1295: 1278: 1264: 1251: 1233: 1228: 1209:Wayback Machine 1198: 1194: 1180: 1173: 1154: 1138: 1137: 1130: 1090: 1089: 1085: 1070: 1054: 1053: 1049: 1028: 1021: 1010: 999: 987: 976: 961: 948: 947: 940: 936: 893: 871:preconditioners 866: 807: 688: 684: 644: 639: 638: 595: 590: 589: 555: 505: 495: 376: 372: 334: 333: 329:), results in: 283: 256: 193: 171: 148: 147: 140: 139: 133: 127: 65:discretizations 32: 23: 22: 15: 12: 11: 5: 1469: 1467: 1459: 1458: 1453: 1448: 1438: 1437: 1434: 1433: 1418: 1403: 1388: 1379: 1370: 1364: 1351: 1344: 1335: 1332: 1331: 1330: 1321: 1311: 1299: 1293: 1276: 1262: 1249: 1240:, 1994, SIAM. 1232: 1229: 1227: 1226: 1192: 1171: 1152: 1128: 1101:(3): 388–414. 1083: 1068: 1047: 1037:, 1994, SIAM. 1019: 997: 974: 959: 937: 935: 932: 931: 930: 925: 919: 912: 905: 892: 889: 865: 862: 855: 854: 843: 838: 834: 831: 828: 825: 822: 819: 814: 810: 805: 801: 798: 794: 790: 787: 784: 781: 778: 775: 772: 769: 766: 763: 759: 755: 752: 749: 746: 743: 740: 736: 732: 729: 726: 723: 720: 717: 714: 711: 708: 705: 701: 697: 694: 691: 687: 680: 677: 671: 668: 665: 662: 659: 656: 651: 647: 628: 627: 615: 612: 609: 604: 599: 583: 582: 571: 567: 562: 558: 554: 549: 543: 538: 534: 531: 528: 525: 522: 519: 514: 509: 502: 498: 493: 489: 486: 482: 478: 475: 472: 469: 466: 463: 460: 457: 454: 451: 447: 443: 440: 437: 434: 431: 428: 424: 420: 417: 414: 411: 408: 405: 402: 399: 396: 393: 389: 385: 382: 379: 375: 368: 365: 359: 356: 353: 350: 347: 344: 341: 311: 310: 299: 295: 290: 286: 282: 277: 271: 263: 259: 254: 251: 247: 243: 240: 237: 234: 231: 228: 225: 222: 219: 216: 213: 210: 206: 202: 199: 196: 190: 183: 178: 175: 169: 166: 163: 160: 155: 151: 129:Main article: 126: 123: 58:linear systems 24: 14: 13: 10: 9: 6: 4: 3: 2: 1468: 1457: 1454: 1452: 1449: 1447: 1444: 1443: 1441: 1431: 1427: 1423: 1419: 1416: 1415:9781420034394 1412: 1409:. CRC Press. 1408: 1404: 1401: 1400:9781483137858 1397: 1393: 1389: 1385: 1380: 1376: 1371: 1367: 1365:0-471-30932-X 1361: 1357: 1352: 1349: 1345: 1342: 1338: 1337: 1333: 1328: 1325: 1322: 1319: 1315: 1312: 1309: 1308: 1303: 1300: 1296: 1290: 1286: 1282: 1277: 1273: 1269: 1265: 1263:0-89871-461-3 1259: 1255: 1250: 1247: 1246:0-89871-321-8 1243: 1239: 1235: 1234: 1230: 1223: 1222:0-89871-462-1 1219: 1215: 1211: 1210: 1206: 1203: 1196: 1193: 1189: 1188: 1183: 1178: 1176: 1172: 1167: 1163: 1159: 1155: 1153:0-471-90170-9 1149: 1145: 1141: 1135: 1133: 1129: 1124: 1120: 1116: 1112: 1108: 1104: 1100: 1096: 1095: 1087: 1084: 1079: 1075: 1071: 1069:0-471-09725-X 1065: 1061: 1057: 1051: 1048: 1044: 1043:0-89871-321-8 1040: 1036: 1032: 1026: 1024: 1020: 1016: 1013: 1008: 1006: 1004: 1002: 998: 994: 990: 985: 983: 981: 979: 975: 970: 966: 962: 960:0-89871-461-3 956: 952: 945: 943: 939: 933: 929: 926: 923: 920: 917: 913: 910: 909:Jacobi method 906: 903: 899: 895: 894: 890: 888: 886: 882: 878: 874: 872: 863: 861: 858: 841: 836: 829: 826: 823: 817: 812: 808: 803: 796: 792: 788: 785: 782: 776: 773: 767: 764: 761: 757: 753: 747: 744: 738: 734: 730: 727: 724: 718: 715: 709: 706: 703: 699: 695: 689: 685: 678: 675: 669: 663: 660: 657: 649: 645: 637: 636: 635: 633: 613: 610: 607: 602: 588: 587: 586: 569: 560: 556: 541: 536: 529: 526: 523: 517: 512: 500: 496: 491: 484: 480: 476: 473: 470: 464: 461: 455: 452: 449: 445: 441: 435: 432: 426: 422: 418: 415: 412: 406: 403: 397: 394: 391: 387: 383: 377: 373: 366: 363: 357: 351: 348: 345: 339: 332: 331: 330: 328: 324: 320: 316: 297: 288: 284: 269: 261: 257: 249: 245: 241: 235: 232: 226: 220: 217: 214: 208: 204: 200: 194: 188: 181: 176: 173: 164: 158: 153: 149: 138: 137: 136: 132: 124: 122: 120: 116: 112: 108: 104: 99: 97: 93: 89: 85: 80: 78: 74: 70: 66: 63: 59: 56: 51: 49: 45: 41: 37: 30: 19: 1421: 1406: 1391: 1383: 1374: 1355: 1347: 1340: 1326: 1317: 1305: 1284: 1253: 1237: 1200: 1195: 1185: 1165: 1143: 1098: 1092: 1086: 1059: 1050: 1034: 1014: 992: 950: 885:interpolated 880: 875: 867: 859: 856: 631: 629: 584: 326: 322: 318: 314: 312: 134: 100: 81: 52: 46:for solving 39: 33: 1302:Yousef Saad 1182:Yousef Saad 119:approximate 113:methods in 1440:Categories 1231:References 1140:Minoux, M. 111:relaxation 86:, such as 804:− 793:− 777:φ 758:− 748:φ 719:φ 690:φ 650:∗ 646:φ 608:φ 598:∇ 518:φ 508:∇ 492:− 481:− 465:φ 446:− 436:φ 407:φ 378:φ 340:φ 236:φ 221:φ 215:− 205:− 195:φ 159:φ 103:smoothing 1205:Archived 1142:(1986). 891:See also 117:, which 1272:1744713 1162:0868279 1123:0594854 1115:3689446 1078:0720547 969:1744713 1428:  1413:  1398:  1362:  1291:  1270:  1260:  1244:  1220:  1160:  1150:  1121:  1113:  1076:  1066:  1041:  967:  957:  55:sparse 1316:2002 1111:JSTOR 991:2002 934:Notes 1426:ISBN 1411:ISBN 1396:ISBN 1360:ISBN 1289:ISBN 1258:ISBN 1242:ISBN 1218:ISBN 1148:ISBN 1064:ISBN 1039:ISBN 955:ISBN 914:The 907:The 42:are 1103:doi 67:of 34:In 1442:: 1304:, 1283:. 1268:MR 1266:. 1216:, 1184:, 1174:^ 1158:MR 1156:. 1131:^ 1119:MR 1117:. 1109:. 1097:. 1074:MR 1072:. 1033:, 1022:^ 1000:^ 977:^ 965:MR 963:. 941:^ 325:, 317:, 38:, 1432:. 1417:. 1402:. 1368:. 1297:. 1274:. 1248:. 1224:. 1125:. 1105:: 1099:5 1080:. 1045:. 971:. 904:. 881:h 842:, 837:) 833:) 830:y 827:, 824:x 821:( 818:f 813:2 809:h 800:) 797:h 789:y 786:, 783:x 780:( 774:+ 771:) 768:y 765:, 762:h 754:x 751:( 745:+ 742:) 739:h 735:+ 731:y 728:, 725:x 722:( 716:+ 713:) 710:y 707:, 704:h 700:+ 696:x 693:( 686:( 679:4 676:1 670:= 667:) 664:y 661:, 658:x 655:( 632:h 614:f 611:= 603:2 570:. 566:) 561:4 557:h 553:( 548:O 542:+ 537:) 533:) 530:y 527:, 524:x 521:( 513:2 501:2 497:h 488:) 485:h 477:y 474:, 471:x 468:( 462:+ 459:) 456:y 453:, 450:h 442:x 439:( 433:+ 430:) 427:h 423:+ 419:y 416:, 413:x 410:( 404:+ 401:) 398:y 395:, 392:h 388:+ 384:x 381:( 374:( 367:4 364:1 358:= 355:) 352:y 349:, 346:x 343:( 327:y 323:x 319:y 315:x 298:. 294:) 289:2 285:h 281:( 276:O 270:+ 262:2 258:h 253:) 250:h 246:+ 242:x 239:( 233:+ 230:) 227:x 224:( 218:2 212:) 209:h 201:x 198:( 189:= 182:2 177:x 174:d 168:) 165:x 162:( 154:2 150:d 31:. 20:)

Index

Relaxation method
Relaxation (disambiguation)
numerical mathematics
iterative methods
systems of equations
sparse
linear systems
finite-difference
discretizations
differential equations
linear least-squares
linear programming
elliptic partial differential equations
Laplace's equation
Poisson's equation
boundary-value problems
smoothing
Laplace's equation
relaxation
mathematical optimization
approximate
Discrete Poisson equation
preconditioners
Multigrid methods
interpolated
stationary iterative methods
Krylov subspace methods
Jacobi method
Gauss–Seidel method
Successive over-relaxation

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