Knowledge

Unimodular matrix

Source 📝

3311: 1641: 406:
is unimodular. Equivalently, every square submatrix has determinant 0, +1 or −1. A totally unimodular matrix need not be square itself. From the definition it follows that any submatrix of a totally unimodular matrix is itself totally unimodular (TU). Furthermore it follows that any TU matrix
895:; thus, this example says that the incidence matrix of a signed graph is totally unimodular if the signed graph is balanced. The converse is valid for signed graphs without half edges (this generalizes the property of the unoriented incidence matrix of a graph). 1375:
1) entries and in each column, the entries are non-decreasing from top to bottom (so all −1s are on top, then 0s, then 1s are on the bottom). Fujishige showed that the matrix is TU iff every 2-by-2 submatrix has determinant in
635:, is totally unimodular (TU). (The unoriented incidence matrix of a non-bipartite graph is not TU.) More generally, in the appendix to a paper by Heller and Tompkins, A.J. Hoffman and D. Gale prove the following. Let 368: 1412:(1980) proved a full characterization of all TU matrices, which we describe here only informally. Seymour's theorem is that a matrix is TU if and only if it is a certain natural combination of some 506: 195: 560: 1884: 1127: 613: 1079: 154: 1162: 2969: 1793: 1627: 1403: 1977: 1373: 1290: 1950: 1924: 1904: 1837: 1350: 1330: 1310: 1261: 1241: 1217: 1193: 885: 865: 845: 822: 802: 782: 759: 736: 704: 684: 653: 3183: 2402: 1839:, not limited to the integers. In this context, a unimodular matrix is one that is invertible over the ring; equivalently, whose determinant is a 3274: 2320: 256: 3193: 2959: 707: 914:). Thus, such network flow problems with bounded integer capacities have an integral optimal value. Note that this does not apply to 2340: 2245: 411:
is not true, i.e., a matrix with only 0, +1 or −1 entries is not necessarily unimodular. A matrix is TU if and only if its
294: 2994: 2210: 2000:
here refers to matrices with coefficients in some ring (often the integers) which are invertible over that ring, and one uses
445: 2541: 159: 2758: 2395: 2205: 2057: 1409: 915: 40: 2833: 511: 2989: 2511: 1165: 423: 3093: 2964: 2878: 1850: 3198: 3088: 2796: 2476: 1633: 899: 419: 2365: 1632:
This matrix arises as the coefficient matrix of the constraints in the linear programming formulation of the
3233: 3162: 3044: 2904: 2501: 2388: 632: 2177:
Fujishige, Satoru (1984), "A System of Linear inequalities with a Submodular Function on (0, ±1) Vectors",
2166:, Annals of Mathematics Studies, vol. 38, Princeton (NJ): Princeton University Press, pp. 223–246 2095:, Annals of Mathematics Studies, vol. 38, Princeton (NJ): Princeton University Press, pp. 247–254 3103: 2686: 2491: 2028: 1084: 3049: 2786: 2636: 2631: 2466: 2441: 2436: 1445: 577: 234: 214: 3310: 1667: 1640: 1168:
at most one). This and several other if-and-only-if characterizations are proven in Schrijver (1998).
951:, each of whose arcs has an arbitrary orientation (it is not necessary that there exist a root vertex 3243: 2601: 2431: 2411: 2023: 210: 131: 925:
is (or can be permuted into) a 0-1 matrix in which for every row, the 1s appear consecutively, then
3264: 3238: 2816: 2621: 2611: 2347: 2328: 2033: 1983: 1844: 281: 120: 1049: 137: 3315: 3269: 3259: 3213: 3208: 3137: 3073: 2939: 2676: 2671: 2606: 2596: 2461: 2280:, Contemporary Developments in Finite Fields and Applications, World Scientific, pp. 244–253 1840: 1817: 1132: 918:, in which it is possible to have fractional optimal value even with bounded integer capacities. 616: 431: 250: 3347: 3326: 3113: 3108: 3098: 3078: 3039: 3034: 2858: 2843: 2838: 2829: 2824: 2771: 2666: 2616: 2561: 2531: 2526: 2506: 2496: 2456: 2336: 2316: 2310: 2241: 2132: 1992: 1652: 1430: 907: 400: 288: 277: 270: 74: 36: 1379: 3321: 3289: 3218: 3157: 3152: 3132: 3068: 2974: 2944: 2929: 2914: 2909: 2848: 2801: 2776: 2766: 2737: 2656: 2651: 2626: 2556: 2536: 2446: 2426: 2219: 2186: 2159: 2088: 1810: 408: 86: 1955: 3019: 2954: 2934: 2919: 2899: 2883: 2781: 2712: 2702: 2661: 2546: 2516: 2018: 2013: 1358: 1266: 628: 262: 221: 1929: 3279: 3223: 3203: 3188: 3147: 3024: 2984: 2949: 2873: 2812: 2791: 2732: 2722: 2707: 2641: 2586: 2576: 2571: 2481: 2155: 2151: 2084: 2061: 1909: 1889: 1822: 1335: 1315: 1295: 1246: 1226: 1202: 1196: 1178: 1172: 870: 850: 830: 807: 787: 767: 744: 721: 689: 669: 638: 427: 227: 66: 28: 3341: 3284: 3142: 3083: 3014: 3004: 2999: 2924: 2853: 2727: 2717: 2646: 2566: 2551: 2486: 2370: 2278:
The density of unimodular matrices over integrally closed subrings of function fields
2223: 2191: 891:
It was realized later that these conditions define an incidence matrix of a balanced
664: 266: 245: 63: 3167: 3124: 3029: 2742: 2681: 2591: 2471: 2052: 929:
is TU. (The same holds for columns since the transpose of a TU matrix is also TU.)
903: 892: 2265:, Linear Algebra and its applications, vol. 434, Elsevier, pp. 1319–1324 2120: 17: 48:
Integer matrices with +1 or -1 determinant; invertible over the integers. GL_n(Z)
3009: 2979: 2747: 2581: 2451: 2083:
Heller, I.; Tompkins, C.B. (1956), "An Extension of a Theorem of Dantzig's", in
1814: 1332:
is totally unimodular if and only if every simple arbitrarily-oriented cycle in
70: 52: 1129:(which is a row vector of the same width as the matrix) has all its entries in 3060: 2521: 2136: 3294: 2868: 1802:
totally unimodular, since it has a square submatrix of determinant −2.
412: 403: 910:
problems yield a coefficient matrix with these properties (and with empty
3228: 206: 2309:
Papadimitriou, Christos H.; Steiglitz, Kenneth (1998), "Section 13.2",
78: 2376:
Software for testing total unimodularity by M. Walter and K. Truemper
1220: 434:(has an integral optimum, when any optimum exists). Specifically, if 2375: 2295:, Linear algebra and its applications, Elsevier, pp. 2675–2682 2154:, J.B. (1956), "Integral Boundary Points of Convex Polyhedra", in 291:
of two unimodular matrices is also unimodular. This follows since
2380: 1042:
5. Ghouila-Houri showed that a matrix is TU iff for every subset
2384: 574:
is integral, every extreme point of the feasible region (e.g.
2240:(rev. 3rd ed.). Springer. p. 510, Section XIII.3. 2293:
The probability of rectangular unimodular matrices over Fq
1926:
matrix is said to be unimodular if it can be extended with
2263:
Natural Density of Rectangular Unimodular Integer Matrices
363:{\displaystyle \det(A\otimes B)=(\det A)^{q}(\det B)^{p},} 936:
is TU. The rows of a network matrix correspond to a tree
2366:
Mathematical Programming Glossary by Harvey J. Greenberg
501:{\displaystyle \{\min c^{\top }x\mid Ax\geq b,x\geq 0\}} 73:+1 or −1. Equivalently, it is an integer matrix that is 761:
contains at most two non-zero (i.e., +1 or −1) entries;
418:
Totally unimodular matrices are extremely important in
2312:
Combinatorial Optimization: Algorithms and Complexity
2208:, P. D. (1980), "Decomposition of regular matroids", 2004:
to mean matrices that are invertible over the field.
1958: 1932: 1912: 1892: 1853: 1825: 1655: 1433: 1382: 1361: 1352:
consists of alternating forwards and backwards arcs.
1338: 1318: 1298: 1269: 1249: 1229: 1205: 1181: 1135: 1087: 1052: 873: 853: 833: 810: 790: 770: 747: 724: 692: 672: 641: 580: 514: 448: 297: 190:{\displaystyle \operatorname {GL} _{n}(\mathbb {Z} )} 162: 140: 2352:
Combinatorial Optimization: Polyhedra and Efficiency
276:
The unimodular matrix used (possibly implicitly) in
3252: 3176: 3122: 3058: 2892: 2810: 2756: 2695: 2419: 2315:, Mineola, N.Y.: Dover Publications, p. 316, 1971: 1944: 1918: 1898: 1878: 1831: 1787: 1621: 1416:and some copies of a particular 5-by-5 TU matrix. 1397: 1367: 1344: 1324: 1304: 1284: 1255: 1235: 1211: 1187: 1156: 1121: 1073: 879: 859: 847:have opposite signs, then the rows of both are in 839: 816: 796: 776: 753: 730: 706:. Then the following four conditions together are 698: 678: 647: 615:) is integral and thus the feasible region is an 607: 554: 500: 362: 189: 148: 255:the three transformation matrices in the ternary 27:This article is about matrices whose entries are 1424:1. The following matrix is totally unimodular: 631:, which is the coefficient matrix for bipartite 555:{\displaystyle \{\max c^{\top }x\mid Ax\leq b\}} 518: 452: 442:is integral, then linear programs of forms like 341: 322: 298: 85:that is its inverse (these are equivalent under 399:(TU matrix) is a matrix for which every square 784:have the same sign, then the row of one is in 663:matrix whose rows can be partitioned into two 217:, i.e. the following matrices are unimodular: 2396: 426:since they give a quick way to verify that a 8: 2261:Rosenthal, J.; Maze, G.; Wagner, U. (2011), 2066:Integral Boundary Points of Convex Polyhedra 1151: 1136: 602: 581: 549: 515: 495: 449: 111:is unimodular, has an integer solution. The 2970:Fundamental (linear differential equation) 2403: 2389: 2381: 2070:50 Years of Integer Programming, 1958-2008 1879:{\displaystyle \operatorname {GL} _{n}(R)} 2190: 1963: 1957: 1931: 1911: 1891: 1858: 1852: 1824: 1813:considers matrices with entries from any 1666: 1654: 1444: 1432: 1381: 1360: 1337: 1317: 1297: 1268: 1248: 1228: 1204: 1180: 1134: 1092: 1086: 1051: 963:").The columns correspond to another set 872: 852: 832: 809: 789: 769: 746: 723: 691: 671: 640: 579: 525: 513: 459: 447: 351: 332: 296: 180: 179: 167: 161: 142: 141: 139: 2333:Theory of Linear and Integer Programming 2121:"Incidence matrices and interval graphs" 1081:of signs to rows so that the signed sum 627:1. The unoriented incidence matrix of a 407:has only 0, +1 or −1 entries. The 3275:Matrix representation of conic sections 2164:Linear Inequalities and Related Systems 2119:Fulkerson, D. R.; Gross, O. A. (1965). 2093:Linear Inequalities and Related Systems 2044: 827:If two non-zero entries in a column of 764:If two non-zero entries in a column of 2105:T. Zaslavsky (1982), "Signed graphs," 1175:proved the following theorem. Suppose 2068:", in M. Jünger; et al. (eds.), 921:3. The consecutive-ones property: if 257:tree of primitive Pythagorean triples 7: 261:Certain transformation matrices for 2179:Linear Algebra and Its Applications 1122:{\displaystyle \sum _{r\in R}s(r)r} 955:such that the tree is "rooted into 2276:Micheli, G.; Schnyder, R. (2016), 1636:problem on the following network: 623:Common totally unimodular matrices 608:{\displaystyle \{x\mid Ax\geq b\}} 526: 460: 25: 2072:, Springer-Verlag, pp. 49–50 107:both have integer components and 3309: 2371:Unimodular Matrix from MathWorld 1639: 1046:of rows, there is an assignment 3177:Used in science and engineering 2211:Journal of Combinatorial Theory 1979:to a unimodular square matrix. 1263:is the 0-1 incidence matrix of 967:of arcs on the same vertex set 201:Examples of unimodular matrices 2420:Explicitly constrained entries 2125:Pacific Journal of Mathematics 2064:, J. (2010), "Introduction to 1873: 1867: 1279: 1273: 1113: 1107: 1062: 1039:See more in Schrijver (2003). 971:. To compute the entry at row 562:have integral optima, for any 348: 338: 329: 319: 313: 301: 269:(both with determinant 1) and 184: 176: 1: 3194:Fundamental (computer vision) 916:multi-commodity flow problems 81:: there is an integer matrix 2224:10.1016/0095-8956(80)90075-1 2192:10.1016/0024-3795(84)90147-2 2107:Discrete Applied Mathematics 1164:(i.e. the row-submatrix has 1074:{\displaystyle s:R\to \pm 1} 149:{\displaystyle \mathbb {Z} } 41:Unimodular polynomial matrix 2960:Duplication and elimination 2759:eigenvalues or eigenvectors 1646:2. Any matrix of the form 1355:7. Suppose a matrix has 0-( 1157:{\displaystyle \{0,\pm 1\}} 205:Unimodular matrices form a 119:unimodular matrices form a 3364: 2893:With specific applications 2522:Discrete Fourier Transform 2291:Guo, X.; Yang, G. (2013), 714:to be totally unimodular: 570:is totally unimodular and 424:combinatorial optimization 237:of two unimodular matrices 26: 3303: 3184:Cabibbo–Kobayashi–Maskawa 2811:Satisfying conditions on 2335:. John Wiley & Sons, 397:totally unimodular matrix 1990:has the same meaning as 1788:{\displaystyle A=\left.} 1622:{\displaystyle A=\left.} 420:polyhedral combinatorics 241:Other examples include: 2542:Generalized permutation 2051:The term was coined by 1811:Abstract linear algebra 1806:Abstract linear algebra 1398:{\displaystyle 0,\pm 1} 89:). Thus every equation 3316:Mathematics portal 2029:Total dual integrality 1973: 1946: 1920: 1900: 1880: 1833: 1789: 1623: 1399: 1369: 1346: 1326: 1306: 1286: 1257: 1237: 1213: 1189: 1158: 1123: 1075: 881: 861: 841: 818: 798: 778: 755: 732: 700: 680: 649: 609: 556: 502: 378:are the dimensions of 364: 230:of a unimodular matrix 191: 150: 2109:4, pp. 401–406. 1974: 1972:{\displaystyle R^{m}} 1947: 1921: 1901: 1881: 1834: 1790: 1624: 1400: 1370: 1347: 1327: 1307: 1287: 1258: 1238: 1214: 1190: 1159: 1124: 1076: 1020:appears backwards in 1001:; then the entry is: 882: 862: 842: 819: 799: 779: 756: 733: 701: 681: 650: 610: 557: 503: 365: 215:matrix multiplication 192: 151: 2236:Lang, Serge (2002). 2024:Special linear group 1956: 1930: 1910: 1890: 1851: 1823: 1653: 1431: 1380: 1368:{\displaystyle \pm } 1359: 1336: 1316: 1296: 1285:{\displaystyle V(G)} 1267: 1247: 1227: 1203: 1199:without 2-dicycles, 1179: 1133: 1085: 1050: 871: 851: 831: 808: 788: 768: 745: 722: 690: 670: 639: 578: 512: 446: 295: 251:Permutation matrices 211:general linear group 160: 138: 132:general linear group 3265:Linear independence 2512:Diagonally dominant 2348:Alexander Schrijver 2329:Alexander Schrijver 2034:Hermite normal form 1945:{\displaystyle m-k} 1031:does not appear in 1009:appears forward in 804:, and the other in 391:Total unimodularity 282:Hermite normal form 156:, which is denoted 37:polynomial matrices 35:in connection with 3270:Matrix exponential 3260:Jordan normal form 3094:Fisher information 2965:Euclidean distance 2879:Totally unimodular 1969: 1942: 1916: 1896: 1876: 1829: 1785: 1776: 1619: 1610: 1395: 1365: 1342: 1322: 1302: 1282: 1253: 1233: 1219:is the set of all 1209: 1185: 1154: 1119: 1103: 1071: 877: 857: 837: 814: 794: 774: 751: 728: 696: 676: 645: 605: 552: 498: 360: 187: 146: 31:. For use of term 18:Totally unimodular 3335: 3334: 3327:Category:Matrices 3199:Fuzzy associative 3089:Doubly stochastic 2797:Positive-definite 2477:Block tridiagonal 2322:978-0-486-40258-1 1919:{\displaystyle m} 1899:{\displaystyle k} 1832:{\displaystyle R} 1420:Concrete examples 1345:{\displaystyle G} 1325:{\displaystyle A} 1305:{\displaystyle P} 1256:{\displaystyle A} 1236:{\displaystyle G} 1212:{\displaystyle P} 1188:{\displaystyle G} 1088: 908:minimum cost flow 880:{\displaystyle C} 860:{\displaystyle B} 840:{\displaystyle A} 817:{\displaystyle C} 797:{\displaystyle B} 777:{\displaystyle A} 754:{\displaystyle A} 731:{\displaystyle A} 699:{\displaystyle C} 679:{\displaystyle B} 648:{\displaystyle A} 289:Kronecker product 278:lattice reduction 273:(determinant −1). 57:unimodular matrix 16:(Redirected from 3355: 3322:List of matrices 3314: 3313: 3290:Row echelon form 3234:State transition 3163:Seidel adjacency 3045:Totally positive 2905:Alternating sign 2502:Complex Hadamard 2405: 2398: 2391: 2382: 2355: 2325: 2297: 2296: 2288: 2282: 2281: 2273: 2267: 2266: 2258: 2252: 2251: 2233: 2227: 2226: 2202: 2196: 2195: 2194: 2174: 2168: 2167: 2147: 2141: 2140: 2116: 2110: 2103: 2097: 2096: 2080: 2074: 2073: 2049: 1978: 1976: 1975: 1970: 1968: 1967: 1951: 1949: 1948: 1943: 1925: 1923: 1922: 1917: 1905: 1903: 1902: 1897: 1886:. A rectangular 1885: 1883: 1882: 1877: 1863: 1862: 1838: 1836: 1835: 1830: 1794: 1792: 1791: 1786: 1781: 1777: 1769: 1763: 1722: 1716: 1675: 1669: 1643: 1628: 1626: 1625: 1620: 1615: 1611: 1414:network matrices 1404: 1402: 1401: 1396: 1374: 1372: 1371: 1366: 1351: 1349: 1348: 1343: 1331: 1329: 1328: 1323: 1311: 1309: 1308: 1303: 1291: 1289: 1288: 1283: 1262: 1260: 1259: 1254: 1242: 1240: 1239: 1234: 1218: 1216: 1215: 1210: 1194: 1192: 1191: 1186: 1163: 1161: 1160: 1155: 1128: 1126: 1125: 1120: 1102: 1080: 1078: 1077: 1072: 984: 950: 886: 884: 883: 878: 866: 864: 863: 858: 846: 844: 843: 838: 823: 821: 820: 815: 803: 801: 800: 795: 783: 781: 780: 775: 760: 758: 757: 752: 741:Every column of 738:is 0, +1, or −1; 737: 735: 734: 729: 705: 703: 702: 697: 685: 683: 682: 677: 654: 652: 651: 646: 614: 612: 611: 606: 561: 559: 558: 553: 530: 529: 507: 505: 504: 499: 464: 463: 369: 367: 366: 361: 356: 355: 337: 336: 196: 194: 193: 188: 183: 172: 171: 155: 153: 152: 147: 145: 98: 21: 3363: 3362: 3358: 3357: 3356: 3354: 3353: 3352: 3338: 3337: 3336: 3331: 3308: 3299: 3248: 3172: 3118: 3054: 2888: 2806: 2752: 2691: 2492:Centrosymmetric 2415: 2409: 2362: 2346: 2323: 2308: 2305: 2300: 2290: 2289: 2285: 2275: 2274: 2270: 2260: 2259: 2255: 2248: 2235: 2234: 2230: 2204: 2203: 2199: 2176: 2175: 2171: 2162:, A.W. (eds.), 2150:Hoffman, A.J.; 2149: 2148: 2144: 2118: 2117: 2113: 2104: 2100: 2091:, A.W. (eds.), 2082: 2081: 2077: 2056: 2050: 2046: 2042: 2019:Regular matroid 2014:Balanced matrix 2010: 1959: 1954: 1953: 1928: 1927: 1908: 1907: 1888: 1887: 1854: 1849: 1848: 1821: 1820: 1808: 1775: 1774: 1768: 1761: 1760: 1755: 1747: 1742: 1734: 1728: 1727: 1721: 1714: 1713: 1708: 1700: 1695: 1687: 1681: 1680: 1674: 1662: 1651: 1650: 1609: 1608: 1600: 1592: 1584: 1579: 1574: 1568: 1567: 1562: 1554: 1549: 1541: 1533: 1527: 1526: 1521: 1516: 1508: 1500: 1495: 1486: 1485: 1477: 1472: 1467: 1462: 1454: 1440: 1429: 1428: 1422: 1378: 1377: 1357: 1356: 1334: 1333: 1314: 1313: 1294: 1293: 1265: 1264: 1245: 1244: 1225: 1224: 1201: 1200: 1177: 1176: 1171:6. Hoffman and 1131: 1130: 1083: 1082: 1048: 1047: 976: 937: 869: 868: 849: 848: 829: 828: 806: 805: 786: 785: 766: 765: 743: 742: 720: 719: 718:Every entry in 688: 687: 668: 667: 637: 636: 629:bipartite graph 625: 576: 575: 521: 510: 509: 455: 444: 443: 393: 386:, respectively. 347: 328: 293: 292: 246:Pascal matrices 222:Identity matrix 203: 163: 158: 157: 136: 135: 127: ×  115: ×  90: 49: 44: 29:integer numbers 23: 22: 15: 12: 11: 5: 3361: 3359: 3351: 3350: 3340: 3339: 3333: 3332: 3330: 3329: 3324: 3319: 3304: 3301: 3300: 3298: 3297: 3292: 3287: 3282: 3280:Perfect matrix 3277: 3272: 3267: 3262: 3256: 3254: 3250: 3249: 3247: 3246: 3241: 3236: 3231: 3226: 3221: 3216: 3211: 3206: 3201: 3196: 3191: 3186: 3180: 3178: 3174: 3173: 3171: 3170: 3165: 3160: 3155: 3150: 3145: 3140: 3135: 3129: 3127: 3120: 3119: 3117: 3116: 3111: 3106: 3101: 3096: 3091: 3086: 3081: 3076: 3071: 3065: 3063: 3056: 3055: 3053: 3052: 3050:Transformation 3047: 3042: 3037: 3032: 3027: 3022: 3017: 3012: 3007: 3002: 2997: 2992: 2987: 2982: 2977: 2972: 2967: 2962: 2957: 2952: 2947: 2942: 2937: 2932: 2927: 2922: 2917: 2912: 2907: 2902: 2896: 2894: 2890: 2889: 2887: 2886: 2881: 2876: 2871: 2866: 2861: 2856: 2851: 2846: 2841: 2836: 2827: 2821: 2819: 2808: 2807: 2805: 2804: 2799: 2794: 2789: 2787:Diagonalizable 2784: 2779: 2774: 2769: 2763: 2761: 2757:Conditions on 2754: 2753: 2751: 2750: 2745: 2740: 2735: 2730: 2725: 2720: 2715: 2710: 2705: 2699: 2697: 2693: 2692: 2690: 2689: 2684: 2679: 2674: 2669: 2664: 2659: 2654: 2649: 2644: 2639: 2637:Skew-symmetric 2634: 2632:Skew-Hermitian 2629: 2624: 2619: 2614: 2609: 2604: 2599: 2594: 2589: 2584: 2579: 2574: 2569: 2564: 2559: 2554: 2549: 2544: 2539: 2534: 2529: 2524: 2519: 2514: 2509: 2504: 2499: 2494: 2489: 2484: 2479: 2474: 2469: 2467:Block-diagonal 2464: 2459: 2454: 2449: 2444: 2442:Anti-symmetric 2439: 2437:Anti-Hermitian 2434: 2429: 2423: 2421: 2417: 2416: 2410: 2408: 2407: 2400: 2393: 2385: 2379: 2378: 2373: 2368: 2361: 2360:External links 2358: 2357: 2356: 2344: 2343:(mathematical) 2326: 2321: 2304: 2301: 2299: 2298: 2283: 2268: 2253: 2246: 2228: 2218:(3): 305–359, 2197: 2169: 2142: 2131:(3): 835–855. 2111: 2098: 2075: 2043: 2041: 2038: 2037: 2036: 2031: 2026: 2021: 2016: 2009: 2006: 1966: 1962: 1941: 1938: 1935: 1915: 1895: 1875: 1872: 1869: 1866: 1861: 1857: 1828: 1807: 1804: 1796: 1795: 1784: 1780: 1773: 1770: 1767: 1764: 1762: 1759: 1756: 1754: 1751: 1748: 1746: 1743: 1741: 1738: 1735: 1733: 1730: 1729: 1726: 1723: 1720: 1717: 1715: 1712: 1709: 1707: 1704: 1701: 1699: 1696: 1694: 1691: 1688: 1686: 1683: 1682: 1679: 1676: 1673: 1670: 1668: 1665: 1661: 1658: 1630: 1629: 1618: 1614: 1607: 1604: 1601: 1599: 1596: 1593: 1591: 1588: 1585: 1583: 1580: 1578: 1575: 1573: 1570: 1569: 1566: 1563: 1561: 1558: 1555: 1553: 1550: 1548: 1545: 1542: 1540: 1537: 1534: 1532: 1529: 1528: 1525: 1522: 1520: 1517: 1515: 1512: 1509: 1507: 1504: 1501: 1499: 1496: 1494: 1491: 1488: 1487: 1484: 1481: 1478: 1476: 1473: 1471: 1468: 1466: 1463: 1461: 1458: 1455: 1453: 1450: 1447: 1446: 1443: 1439: 1436: 1421: 1418: 1394: 1391: 1388: 1385: 1364: 1341: 1321: 1301: 1281: 1278: 1275: 1272: 1252: 1232: 1208: 1197:directed graph 1184: 1153: 1150: 1147: 1144: 1141: 1138: 1118: 1115: 1112: 1109: 1106: 1101: 1098: 1095: 1091: 1070: 1067: 1064: 1061: 1058: 1055: 1037: 1036: 1025: 1014: 985:, look at the 934:network matrix 889: 888: 876: 856: 836: 825: 813: 793: 773: 762: 750: 739: 727: 695: 675: 644: 624: 621: 604: 601: 598: 595: 592: 589: 586: 583: 551: 548: 545: 542: 539: 536: 533: 528: 524: 520: 517: 497: 494: 491: 488: 485: 482: 479: 476: 473: 470: 467: 462: 458: 454: 451: 428:linear program 392: 389: 388: 387: 359: 354: 350: 346: 343: 340: 335: 331: 327: 324: 321: 318: 315: 312: 309: 306: 303: 300: 285: 274: 259: 253: 248: 239: 238: 231: 224: 202: 199: 186: 182: 178: 175: 170: 166: 144: 67:integer matrix 47: 24: 14: 13: 10: 9: 6: 4: 3: 2: 3360: 3349: 3346: 3345: 3343: 3328: 3325: 3323: 3320: 3318: 3317: 3312: 3306: 3305: 3302: 3296: 3293: 3291: 3288: 3286: 3285:Pseudoinverse 3283: 3281: 3278: 3276: 3273: 3271: 3268: 3266: 3263: 3261: 3258: 3257: 3255: 3253:Related terms 3251: 3245: 3244:Z (chemistry) 3242: 3240: 3237: 3235: 3232: 3230: 3227: 3225: 3222: 3220: 3217: 3215: 3212: 3210: 3207: 3205: 3202: 3200: 3197: 3195: 3192: 3190: 3187: 3185: 3182: 3181: 3179: 3175: 3169: 3166: 3164: 3161: 3159: 3156: 3154: 3151: 3149: 3146: 3144: 3141: 3139: 3136: 3134: 3131: 3130: 3128: 3126: 3121: 3115: 3112: 3110: 3107: 3105: 3102: 3100: 3097: 3095: 3092: 3090: 3087: 3085: 3082: 3080: 3077: 3075: 3072: 3070: 3067: 3066: 3064: 3062: 3057: 3051: 3048: 3046: 3043: 3041: 3038: 3036: 3033: 3031: 3028: 3026: 3023: 3021: 3018: 3016: 3013: 3011: 3008: 3006: 3003: 3001: 2998: 2996: 2993: 2991: 2988: 2986: 2983: 2981: 2978: 2976: 2973: 2971: 2968: 2966: 2963: 2961: 2958: 2956: 2953: 2951: 2948: 2946: 2943: 2941: 2938: 2936: 2933: 2931: 2928: 2926: 2923: 2921: 2918: 2916: 2913: 2911: 2908: 2906: 2903: 2901: 2898: 2897: 2895: 2891: 2885: 2882: 2880: 2877: 2875: 2872: 2870: 2867: 2865: 2862: 2860: 2857: 2855: 2852: 2850: 2847: 2845: 2842: 2840: 2837: 2835: 2831: 2828: 2826: 2823: 2822: 2820: 2818: 2814: 2809: 2803: 2800: 2798: 2795: 2793: 2790: 2788: 2785: 2783: 2780: 2778: 2775: 2773: 2770: 2768: 2765: 2764: 2762: 2760: 2755: 2749: 2746: 2744: 2741: 2739: 2736: 2734: 2731: 2729: 2726: 2724: 2721: 2719: 2716: 2714: 2711: 2709: 2706: 2704: 2701: 2700: 2698: 2694: 2688: 2685: 2683: 2680: 2678: 2675: 2673: 2670: 2668: 2665: 2663: 2660: 2658: 2655: 2653: 2650: 2648: 2645: 2643: 2640: 2638: 2635: 2633: 2630: 2628: 2625: 2623: 2620: 2618: 2615: 2613: 2610: 2608: 2605: 2603: 2602:Pentadiagonal 2600: 2598: 2595: 2593: 2590: 2588: 2585: 2583: 2580: 2578: 2575: 2573: 2570: 2568: 2565: 2563: 2560: 2558: 2555: 2553: 2550: 2548: 2545: 2543: 2540: 2538: 2535: 2533: 2530: 2528: 2525: 2523: 2520: 2518: 2515: 2513: 2510: 2508: 2505: 2503: 2500: 2498: 2495: 2493: 2490: 2488: 2485: 2483: 2480: 2478: 2475: 2473: 2470: 2468: 2465: 2463: 2460: 2458: 2455: 2453: 2450: 2448: 2445: 2443: 2440: 2438: 2435: 2433: 2432:Anti-diagonal 2430: 2428: 2425: 2424: 2422: 2418: 2413: 2406: 2401: 2399: 2394: 2392: 2387: 2386: 2383: 2377: 2374: 2372: 2369: 2367: 2364: 2363: 2359: 2353: 2349: 2345: 2342: 2341:0-471-98232-6 2338: 2334: 2330: 2327: 2324: 2318: 2314: 2313: 2307: 2306: 2302: 2294: 2287: 2284: 2279: 2272: 2269: 2264: 2257: 2254: 2249: 2247:0-387-95385-X 2243: 2239: 2232: 2229: 2225: 2221: 2217: 2213: 2212: 2207: 2201: 2198: 2193: 2188: 2184: 2180: 2173: 2170: 2165: 2161: 2157: 2153: 2146: 2143: 2138: 2134: 2130: 2126: 2122: 2115: 2112: 2108: 2102: 2099: 2094: 2090: 2086: 2079: 2076: 2071: 2067: 2063: 2059: 2054: 2048: 2045: 2039: 2035: 2032: 2030: 2027: 2025: 2022: 2020: 2017: 2015: 2012: 2011: 2007: 2005: 2003: 1999: 1995: 1994: 1989: 1985: 1980: 1964: 1960: 1939: 1936: 1933: 1913: 1893: 1870: 1864: 1859: 1855: 1846: 1842: 1826: 1819: 1816: 1812: 1805: 1803: 1801: 1782: 1778: 1771: 1765: 1757: 1752: 1749: 1744: 1739: 1736: 1731: 1724: 1718: 1710: 1705: 1702: 1697: 1692: 1689: 1684: 1677: 1671: 1663: 1659: 1656: 1649: 1648: 1647: 1644: 1642: 1637: 1635: 1616: 1612: 1605: 1602: 1597: 1594: 1589: 1586: 1581: 1576: 1571: 1564: 1559: 1556: 1551: 1546: 1543: 1538: 1535: 1530: 1523: 1518: 1513: 1510: 1505: 1502: 1497: 1492: 1489: 1482: 1479: 1474: 1469: 1464: 1459: 1456: 1451: 1448: 1441: 1437: 1434: 1427: 1426: 1425: 1419: 1417: 1415: 1411: 1406: 1392: 1389: 1386: 1383: 1362: 1353: 1339: 1319: 1299: 1276: 1270: 1250: 1230: 1222: 1206: 1198: 1182: 1174: 1169: 1167: 1148: 1145: 1142: 1139: 1116: 1110: 1104: 1099: 1096: 1093: 1089: 1068: 1065: 1059: 1056: 1053: 1045: 1040: 1034: 1030: 1026: 1023: 1019: 1015: 1012: 1008: 1004: 1003: 1002: 1000: 996: 992: 988: 983: 979: 974: 970: 966: 962: 959:" or "out of 958: 954: 948: 944: 940: 935: 930: 928: 924: 919: 917: 913: 909: 905: 901: 896: 894: 874: 867:, or both in 854: 834: 826: 811: 791: 771: 763: 748: 740: 725: 717: 716: 715: 713: 709: 693: 673: 666: 665:disjoint sets 662: 658: 642: 634: 630: 622: 620: 618: 599: 596: 593: 590: 587: 584: 573: 569: 565: 546: 543: 540: 537: 534: 531: 522: 492: 489: 486: 483: 480: 477: 474: 471: 468: 465: 456: 441: 437: 433: 429: 425: 421: 416: 414: 410: 405: 402: 398: 390: 385: 381: 377: 373: 357: 352: 344: 333: 325: 316: 310: 307: 304: 290: 286: 283: 279: 275: 272: 268: 264: 260: 258: 254: 252: 249: 247: 244: 243: 242: 236: 232: 229: 225: 223: 220: 219: 218: 216: 212: 208: 200: 198: 173: 168: 164: 133: 130: 126: 122: 118: 114: 110: 106: 102: 97: 93: 88: 87:Cramer's rule 84: 80: 76: 72: 68: 65: 61: 58: 54: 46: 42: 38: 34: 30: 19: 3307: 3239:Substitution 3125:graph theory 2863: 2622:Quaternionic 2612:Persymmetric 2351: 2332: 2311: 2292: 2286: 2277: 2271: 2262: 2256: 2237: 2231: 2215: 2214:, Series B, 2209: 2200: 2182: 2178: 2172: 2163: 2145: 2128: 2124: 2114: 2106: 2101: 2092: 2078: 2069: 2065: 2053:Claude Berge 2047: 2002:non-singular 2001: 1997: 1993:non-singular 1991: 1987: 1981: 1809: 1799: 1797: 1645: 1638: 1634:maximum flow 1631: 1423: 1413: 1407: 1354: 1170: 1043: 1041: 1038: 1032: 1028: 1021: 1017: 1010: 1006: 998: 994: 990: 986: 981: 977: 972: 968: 964: 960: 956: 952: 946: 942: 938: 933: 931: 926: 922: 920: 911: 904:maximum flow 897: 893:signed graph 890: 711: 660: 656: 626: 619:polyhedron. 571: 567: 563: 439: 435: 417: 401:non-singular 396: 394: 383: 379: 375: 371: 284:of matrices. 240: 204: 128: 124: 116: 112: 108: 104: 100: 95: 91: 82: 59: 56: 50: 45: 32: 3214:Hamiltonian 3138:Biadjacency 3074:Correlation 2990:Householder 2940:Commutation 2677:Vandermonde 2672:Tridiagonal 2607:Permutation 2597:Nonnegative 2582:Matrix unit 2462:Bisymmetric 2185:: 253–266, 1847:is denoted 1815:commutative 1166:discrepancy 975:and column 900:constraints 566:. Hence if 280:and in the 123:called the 71:determinant 53:mathematics 3114:Transition 3109:Stochastic 3079:Covariance 3061:statistics 3040:Symplectic 3035:Similarity 2864:Unimodular 2859:Orthogonal 2844:Involutory 2839:Invertible 2834:Projection 2830:Idempotent 2772:Convergent 2667:Triangular 2617:Polynomial 2562:Hessenberg 2532:Equivalent 2527:Elementary 2507:Copositive 2497:Conference 2457:Bidiagonal 2354:, Springer 2303:References 1998:Unimodular 1988:unimodular 1016:−1 if arc 1005:+1 if arc 708:sufficient 438:is TU and 271:reflection 75:invertible 33:unimodular 3295:Wronskian 3219:Irregular 3209:Gell-Mann 3158:Laplacian 3153:Incidence 3133:Adjacency 3104:Precision 3069:Centering 2975:Generator 2945:Confusion 2930:Circulant 2910:Augmented 2869:Unipotent 2849:Nilpotent 2825:Congruent 2802:Stieltjes 2777:Defective 2767:Companion 2738:Redheffer 2657:Symmetric 2652:Sylvester 2627:Signature 2557:Hermitian 2537:Frobenius 2447:Arrowhead 2427:Alternant 2137:0030-8730 1937:− 1865:⁡ 1772:⋮ 1766:⋮ 1758:⋯ 1750:− 1745:⋯ 1732:⋯ 1725:⋮ 1719:⋮ 1711:⋯ 1698:⋯ 1685:⋯ 1678:⋮ 1672:⋮ 1603:− 1557:− 1511:− 1503:− 1457:− 1449:− 1390:± 1363:± 1146:± 1097:∈ 1090:∑ 1066:± 1063:→ 1027:0 if arc 932:4. Every 597:≥ 588:∣ 544:≤ 535:∣ 527:⊤ 490:≥ 478:≥ 469:∣ 461:⊤ 413:transpose 404:submatrix 308:⊗ 174:⁡ 77:over the 3348:Matrices 3342:Category 3123:Used in 3059:Used in 3020:Rotation 2995:Jacobian 2955:Distance 2935:Cofactor 2920:Carleman 2900:Adjugate 2884:Weighing 2817:inverses 2813:products 2782:Definite 2713:Identity 2703:Exchange 2696:Constant 2662:Toeplitz 2547:Hadamard 2517:Diagonal 2350:(2003), 2331:(1998), 2158:, H.W.; 2087:, H.W.; 2060:, A.J.; 2008:See also 1952:rows in 633:matching 617:integral 432:integral 409:converse 267:shearing 263:rotation 207:subgroup 99:, where 79:integers 3224:Overlap 3189:Density 3148:Edmonds 3025:Seifert 2985:Hessian 2950:Coxeter 2874:Unitary 2792:Hurwitz 2723:Of ones 2708:Hilbert 2642:Skyline 2587:Metzler 2577:Logical 2572:Integer 2482:Boolean 2414:classes 2238:Algebra 2206:Seymour 2152:Kruskal 2062:Kruskal 2058:Hoffman 1982:Over a 1843:. This 1410:Seymour 1312:. Then 1292:versus 1221:dipaths 1173:Kruskal 898:2. The 415:is TU. 235:product 228:inverse 209:of the 69:having 3143:Degree 3084:Design 3015:Random 3005:Payoff 3000:Moment 2925:Cartan 2915:Bézout 2854:Normal 2728:Pascal 2718:Lehmer 2647:Sparse 2567:Hollow 2552:Hankel 2487:Cauchy 2412:Matrix 2339:  2319:  2244:  2160:Tucker 2135:  2089:Tucker 2055:, see 1243:, and 655:be an 370:where 213:under 64:square 39:, see 3204:Gamma 3168:Tutte 3030:Shear 2743:Shift 2733:Pauli 2682:Walsh 2592:Moore 2472:Block 2040:Notes 1984:field 1845:group 1195:is a 993:path 686:and 134:over 121:group 62:is a 3010:Pick 2980:Gram 2748:Zero 2452:Band 2337:ISBN 2317:ISBN 2242:ISBN 2156:Kuhn 2133:ISSN 2085:Kuhn 1906:-by- 1841:unit 1818:ring 989:-to- 906:and 710:for 422:and 382:and 374:and 287:The 233:The 226:The 103:and 55:, a 3099:Hat 2832:or 2815:or 2220:doi 2187:doi 1800:not 1798:is 1408:8. 1223:in 997:in 941:= ( 902:of 659:by 519:max 508:or 453:min 430:is 342:det 323:det 299:det 51:In 3344:: 2216:28 2183:63 2181:, 2129:15 2127:. 2123:. 1996:. 1986:, 1856:GL 1405:. 982:st 980:= 945:, 395:A 265:, 197:. 165:GL 94:= 92:Mx 3229:S 2687:Z 2404:e 2397:t 2390:v 2250:. 2222:: 2189:: 2139:. 1965:m 1961:R 1940:k 1934:m 1914:m 1894:k 1874:) 1871:R 1868:( 1860:n 1827:R 1783:. 1779:] 1753:1 1740:1 1737:+ 1706:1 1703:+ 1693:1 1690:+ 1664:[ 1660:= 1657:A 1617:. 1613:] 1606:1 1598:1 1595:+ 1590:1 1587:+ 1582:0 1577:0 1572:0 1565:0 1560:1 1552:0 1547:1 1544:+ 1539:1 1536:+ 1531:0 1524:0 1519:0 1514:1 1506:1 1498:0 1493:1 1490:+ 1483:1 1480:+ 1475:0 1470:0 1465:0 1460:1 1452:1 1442:[ 1438:= 1435:A 1393:1 1387:, 1384:0 1340:G 1320:A 1300:P 1280:) 1277:G 1274:( 1271:V 1251:A 1231:G 1207:P 1183:G 1152:} 1149:1 1143:, 1140:0 1137:{ 1117:r 1114:) 1111:r 1108:( 1105:s 1100:R 1094:r 1069:1 1060:R 1057:: 1054:s 1044:R 1035:. 1033:P 1029:R 1024:, 1022:P 1018:R 1013:, 1011:P 1007:R 999:T 995:P 991:t 987:s 978:C 973:R 969:V 965:C 961:r 957:r 953:r 949:) 947:R 943:V 939:T 927:A 923:A 912:C 887:. 875:C 855:B 835:A 824:; 812:C 792:B 772:A 749:A 726:A 712:A 694:C 674:B 661:n 657:m 643:A 603:} 600:b 594:x 591:A 585:x 582:{ 572:b 568:A 564:c 550:} 547:b 541:x 538:A 532:x 523:c 516:{ 496:} 493:0 487:x 484:, 481:b 475:x 472:A 466:x 457:c 450:{ 440:b 436:A 384:B 380:A 376:q 372:p 358:, 353:p 349:) 345:B 339:( 334:q 330:) 326:A 320:( 317:= 314:) 311:B 305:A 302:( 185:) 181:Z 177:( 169:n 143:Z 129:n 125:n 117:n 113:n 109:M 105:b 101:M 96:b 83:N 60:M 43:. 20:)

Index

Totally unimodular
integer numbers
polynomial matrices
Unimodular polynomial matrix
mathematics
square
integer matrix
determinant
invertible
integers
Cramer's rule
group
general linear group
subgroup
general linear group
matrix multiplication
Identity matrix
inverse
product
Pascal matrices
Permutation matrices
tree of primitive Pythagorean triples
rotation
shearing
reflection
lattice reduction
Hermite normal form
Kronecker product
non-singular
submatrix

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.