Annotation of rpl/lapack/lapack/zuncsd.f, revision 1.1
1.1 ! bertrand 1: RECURSIVE SUBROUTINE ZUNCSD( JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS,
! 2: $ SIGNS, M, P, Q, X11, LDX11, X12,
! 3: $ LDX12, X21, LDX21, X22, LDX22, THETA,
! 4: $ U1, LDU1, U2, LDU2, V1T, LDV1T, V2T,
! 5: $ LDV2T, WORK, LWORK, RWORK, LRWORK,
! 6: $ IWORK, INFO )
! 7: IMPLICIT NONE
! 8: *
! 9: * -- LAPACK routine (version 3.3.0) --
! 10: *
! 11: * -- Contributed by Brian Sutton of the Randolph-Macon College --
! 12: * -- November 2010
! 13: *
! 14: * -- LAPACK is a software package provided by Univ. of Tennessee, --
! 15: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
! 16: *
! 17: * .. Scalar Arguments ..
! 18: CHARACTER JOBU1, JOBU2, JOBV1T, JOBV2T, SIGNS, TRANS
! 19: INTEGER INFO, LDU1, LDU2, LDV1T, LDV2T, LDX11, LDX12,
! 20: $ LDX21, LDX22, LRWORK, LWORK, M, P, Q
! 21: * ..
! 22: * .. Array Arguments ..
! 23: INTEGER IWORK( * )
! 24: DOUBLE PRECISION THETA( * )
! 25: DOUBLE PRECISION RWORK( * )
! 26: COMPLEX*16 U1( LDU1, * ), U2( LDU2, * ), V1T( LDV1T, * ),
! 27: $ V2T( LDV2T, * ), WORK( * ), X11( LDX11, * ),
! 28: $ X12( LDX12, * ), X21( LDX21, * ), X22( LDX22,
! 29: $ * )
! 30: * ..
! 31: *
! 32: * Purpose
! 33: * =======
! 34: *
! 35: * ZUNCSD computes the CS decomposition of an M-by-M partitioned
! 36: * unitary matrix X:
! 37: *
! 38: * [ I 0 0 | 0 0 0 ]
! 39: * [ 0 C 0 | 0 -S 0 ]
! 40: * [ X11 | X12 ] [ U1 | ] [ 0 0 0 | 0 0 -I ] [ V1 | ]**H
! 41: * X = [-----------] = [---------] [---------------------] [---------] .
! 42: * [ X21 | X22 ] [ | U2 ] [ 0 0 0 | I 0 0 ] [ | V2 ]
! 43: * [ 0 S 0 | 0 C 0 ]
! 44: * [ 0 0 I | 0 0 0 ]
! 45: *
! 46: * X11 is P-by-Q. The unitary matrices U1, U2, V1, and V2 are P-by-P,
! 47: * (M-P)-by-(M-P), Q-by-Q, and (M-Q)-by-(M-Q), respectively. C and S are
! 48: * R-by-R nonnegative diagonal matrices satisfying C^2 + S^2 = I, in
! 49: * which R = MIN(P,M-P,Q,M-Q).
! 50: *
! 51: * Arguments
! 52: * =========
! 53: *
! 54: * JOBU1 (input) CHARACTER
! 55: * = 'Y': U1 is computed;
! 56: * otherwise: U1 is not computed.
! 57: *
! 58: * JOBU2 (input) CHARACTER
! 59: * = 'Y': U2 is computed;
! 60: * otherwise: U2 is not computed.
! 61: *
! 62: * JOBV1T (input) CHARACTER
! 63: * = 'Y': V1T is computed;
! 64: * otherwise: V1T is not computed.
! 65: *
! 66: * JOBV2T (input) CHARACTER
! 67: * = 'Y': V2T is computed;
! 68: * otherwise: V2T is not computed.
! 69: *
! 70: * TRANS (input) CHARACTER
! 71: * = 'T': X, U1, U2, V1T, and V2T are stored in row-major
! 72: * order;
! 73: * otherwise: X, U1, U2, V1T, and V2T are stored in column-
! 74: * major order.
! 75: *
! 76: * SIGNS (input) CHARACTER
! 77: * = 'O': The lower-left block is made nonpositive (the
! 78: * "other" convention);
! 79: * otherwise: The upper-right block is made nonpositive (the
! 80: * "default" convention).
! 81: *
! 82: * M (input) INTEGER
! 83: * The number of rows and columns in X.
! 84: *
! 85: * P (input) INTEGER
! 86: * The number of rows in X11 and X12. 0 <= P <= M.
! 87: *
! 88: * Q (input) INTEGER
! 89: * The number of columns in X11 and X21. 0 <= Q <= M.
! 90: *
! 91: * X (input/workspace) COMPLEX*16 array, dimension (LDX,M)
! 92: * On entry, the unitary matrix whose CSD is desired.
! 93: *
! 94: * LDX (input) INTEGER
! 95: * The leading dimension of X. LDX >= MAX(1,M).
! 96: *
! 97: * THETA (output) DOUBLE PRECISION array, dimension (R), in which R =
! 98: * MIN(P,M-P,Q,M-Q).
! 99: * C = DIAG( COS(THETA(1)), ... , COS(THETA(R)) ) and
! 100: * S = DIAG( SIN(THETA(1)), ... , SIN(THETA(R)) ).
! 101: *
! 102: * U1 (output) COMPLEX*16 array, dimension (P)
! 103: * If JOBU1 = 'Y', U1 contains the P-by-P unitary matrix U1.
! 104: *
! 105: * LDU1 (input) INTEGER
! 106: * The leading dimension of U1. If JOBU1 = 'Y', LDU1 >=
! 107: * MAX(1,P).
! 108: *
! 109: * U2 (output) COMPLEX*16 array, dimension (M-P)
! 110: * If JOBU2 = 'Y', U2 contains the (M-P)-by-(M-P) unitary
! 111: * matrix U2.
! 112: *
! 113: * LDU2 (input) INTEGER
! 114: * The leading dimension of U2. If JOBU2 = 'Y', LDU2 >=
! 115: * MAX(1,M-P).
! 116: *
! 117: * V1T (output) COMPLEX*16 array, dimension (Q)
! 118: * If JOBV1T = 'Y', V1T contains the Q-by-Q matrix unitary
! 119: * matrix V1**H.
! 120: *
! 121: * LDV1T (input) INTEGER
! 122: * The leading dimension of V1T. If JOBV1T = 'Y', LDV1T >=
! 123: * MAX(1,Q).
! 124: *
! 125: * V2T (output) COMPLEX*16 array, dimension (M-Q)
! 126: * If JOBV2T = 'Y', V2T contains the (M-Q)-by-(M-Q) unitary
! 127: * matrix V2**H.
! 128: *
! 129: * LDV2T (input) INTEGER
! 130: * The leading dimension of V2T. If JOBV2T = 'Y', LDV2T >=
! 131: * MAX(1,M-Q).
! 132: *
! 133: * WORK (workspace) COMPLEX*16 array, dimension (MAX(1,LWORK))
! 134: * On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
! 135: *
! 136: * LWORK (input) INTEGER
! 137: * The dimension of the array WORK.
! 138: *
! 139: * If LWORK = -1, then a workspace query is assumed; the routine
! 140: * only calculates the optimal size of the WORK array, returns
! 141: * this value as the first entry of the work array, and no error
! 142: * message related to LWORK is issued by XERBLA.
! 143: *
! 144: * RWORK (workspace) DOUBLE PRECISION array, dimension MAX(1,LRWORK)
! 145: * On exit, if INFO = 0, RWORK(1) returns the optimal LRWORK.
! 146: * If INFO > 0 on exit, RWORK(2:R) contains the values PHI(1),
! 147: * ..., PHI(R-1) that, together with THETA(1), ..., THETA(R),
! 148: * define the matrix in intermediate bidiagonal-block form
! 149: * remaining after nonconvergence. INFO specifies the number
! 150: * of nonzero PHI's.
! 151: *
! 152: * LRWORK (input) INTEGER
! 153: * The dimension of the array RWORK.
! 154: *
! 155: * If LRWORK = -1, then a workspace query is assumed; the routine
! 156: * only calculates the optimal size of the RWORK array, returns
! 157: * this value as the first entry of the work array, and no error
! 158: * message related to LRWORK is issued by XERBLA.
! 159: *
! 160: * IWORK (workspace) INTEGER array, dimension (M-Q)
! 161: *
! 162: * INFO (output) INTEGER
! 163: * = 0: successful exit.
! 164: * < 0: if INFO = -i, the i-th argument had an illegal value.
! 165: * > 0: ZBBCSD did not converge. See the description of RWORK
! 166: * above for details.
! 167: *
! 168: * Reference
! 169: * =========
! 170: *
! 171: * [1] Brian D. Sutton. Computing the complete CS decomposition. Numer.
! 172: * Algorithms, 50(1):33-65, 2009.
! 173: *
! 174: * ===================================================================
! 175: *
! 176: * .. Parameters ..
! 177: DOUBLE PRECISION REALONE
! 178: PARAMETER ( REALONE = 1.0D0 )
! 179: COMPLEX*16 NEGONE, ONE, PIOVER2, ZERO
! 180: PARAMETER ( NEGONE = (-1.0D0,0.0D0), ONE = (1.0D0,0.0D0),
! 181: $ PIOVER2 = 1.57079632679489662D0,
! 182: $ ZERO = (0.0D0,0.0D0) )
! 183: * ..
! 184: * .. Local Scalars ..
! 185: CHARACTER TRANST, SIGNST
! 186: INTEGER CHILDINFO, I, IB11D, IB11E, IB12D, IB12E,
! 187: $ IB21D, IB21E, IB22D, IB22E, IBBCSD, IORBDB,
! 188: $ IORGLQ, IORGQR, IPHI, ITAUP1, ITAUP2, ITAUQ1,
! 189: $ ITAUQ2, J, LBBCSDWORK, LBBCSDWORKMIN,
! 190: $ LBBCSDWORKOPT, LORBDBWORK, LORBDBWORKMIN,
! 191: $ LORBDBWORKOPT, LORGLQWORK, LORGLQWORKMIN,
! 192: $ LORGLQWORKOPT, LORGQRWORK, LORGQRWORKMIN,
! 193: $ LORGQRWORKOPT, LWORKMIN, LWORKOPT
! 194: LOGICAL COLMAJOR, DEFAULTSIGNS, LQUERY, WANTU1, WANTU2,
! 195: $ WANTV1T, WANTV2T
! 196: INTEGER LRWORKMIN, LRWORKOPT
! 197: LOGICAL LRQUERY
! 198: * ..
! 199: * .. External Subroutines ..
! 200: EXTERNAL XERBLA, ZBBCSD, ZLACPY, ZLAPMR, ZLAPMT, ZLASCL,
! 201: $ ZLASET, ZUNBDB, ZUNGLQ, ZUNGQR
! 202: * ..
! 203: * .. External Functions ..
! 204: LOGICAL LSAME
! 205: EXTERNAL LSAME
! 206: * ..
! 207: * .. Intrinsic Functions
! 208: INTRINSIC COS, INT, MAX, MIN, SIN
! 209: * ..
! 210: * .. Executable Statements ..
! 211: *
! 212: * Test input arguments
! 213: *
! 214: INFO = 0
! 215: WANTU1 = LSAME( JOBU1, 'Y' )
! 216: WANTU2 = LSAME( JOBU2, 'Y' )
! 217: WANTV1T = LSAME( JOBV1T, 'Y' )
! 218: WANTV2T = LSAME( JOBV2T, 'Y' )
! 219: COLMAJOR = .NOT. LSAME( TRANS, 'T' )
! 220: DEFAULTSIGNS = .NOT. LSAME( SIGNS, 'O' )
! 221: LQUERY = LWORK .EQ. -1
! 222: LRQUERY = LRWORK .EQ. -1
! 223: IF( M .LT. 0 ) THEN
! 224: INFO = -7
! 225: ELSE IF( P .LT. 0 .OR. P .GT. M ) THEN
! 226: INFO = -8
! 227: ELSE IF( Q .LT. 0 .OR. Q .GT. M ) THEN
! 228: INFO = -9
! 229: ELSE IF( ( COLMAJOR .AND. LDX11 .LT. MAX(1,P) ) .OR.
! 230: $ ( .NOT.COLMAJOR .AND. LDX11 .LT. MAX(1,Q) ) ) THEN
! 231: INFO = -11
! 232: ELSE IF( WANTU1 .AND. LDU1 .LT. P ) THEN
! 233: INFO = -14
! 234: ELSE IF( WANTU2 .AND. LDU2 .LT. M-P ) THEN
! 235: INFO = -16
! 236: ELSE IF( WANTV1T .AND. LDV1T .LT. Q ) THEN
! 237: INFO = -18
! 238: ELSE IF( WANTV2T .AND. LDV2T .LT. M-Q ) THEN
! 239: INFO = -20
! 240: END IF
! 241: *
! 242: * Work with transpose if convenient
! 243: *
! 244: IF( INFO .EQ. 0 .AND. MIN( P, M-P ) .LT. MIN( Q, M-Q ) ) THEN
! 245: IF( COLMAJOR ) THEN
! 246: TRANST = 'T'
! 247: ELSE
! 248: TRANST = 'N'
! 249: END IF
! 250: IF( DEFAULTSIGNS ) THEN
! 251: SIGNST = 'O'
! 252: ELSE
! 253: SIGNST = 'D'
! 254: END IF
! 255: CALL ZUNCSD( JOBV1T, JOBV2T, JOBU1, JOBU2, TRANST, SIGNST, M,
! 256: $ Q, P, X11, LDX11, X21, LDX21, X12, LDX12, X22,
! 257: $ LDX22, THETA, V1T, LDV1T, V2T, LDV2T, U1, LDU1,
! 258: $ U2, LDU2, WORK, LWORK, RWORK, LRWORK, IWORK,
! 259: $ INFO )
! 260: RETURN
! 261: END IF
! 262: *
! 263: * Work with permutation [ 0 I; I 0 ] * X * [ 0 I; I 0 ] if
! 264: * convenient
! 265: *
! 266: IF( INFO .EQ. 0 .AND. M-Q .LT. Q ) THEN
! 267: IF( DEFAULTSIGNS ) THEN
! 268: SIGNST = 'O'
! 269: ELSE
! 270: SIGNST = 'D'
! 271: END IF
! 272: CALL ZUNCSD( JOBU2, JOBU1, JOBV2T, JOBV1T, TRANS, SIGNST, M,
! 273: $ M-P, M-Q, X22, LDX22, X21, LDX21, X12, LDX12, X11,
! 274: $ LDX11, THETA, U2, LDU2, U1, LDU1, V2T, LDV2T, V1T,
! 275: $ LDV1T, WORK, LWORK, RWORK, LRWORK, IWORK, INFO )
! 276: RETURN
! 277: END IF
! 278: *
! 279: * Compute workspace
! 280: *
! 281: IF( INFO .EQ. 0 ) THEN
! 282: *
! 283: * Real workspace
! 284: *
! 285: IPHI = 2
! 286: IB11D = IPHI + MAX( 1, Q - 1 )
! 287: IB11E = IB11D + MAX( 1, Q )
! 288: IB12D = IB11E + MAX( 1, Q - 1 )
! 289: IB12E = IB12D + MAX( 1, Q )
! 290: IB21D = IB12E + MAX( 1, Q - 1 )
! 291: IB21E = IB21D + MAX( 1, Q )
! 292: IB22D = IB21E + MAX( 1, Q - 1 )
! 293: IB22E = IB22D + MAX( 1, Q )
! 294: IBBCSD = IB22E + MAX( 1, Q - 1 )
! 295: CALL ZBBCSD( JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS, M, P, Q, 0,
! 296: $ 0, U1, LDU1, U2, LDU2, V1T, LDV1T, V2T, LDV2T, 0,
! 297: $ 0, 0, 0, 0, 0, 0, 0, RWORK, -1, CHILDINFO )
! 298: LBBCSDWORKOPT = INT( RWORK(1) )
! 299: LBBCSDWORKMIN = LBBCSDWORKOPT
! 300: LRWORKOPT = IBBCSD + LBBCSDWORKOPT - 1
! 301: LRWORKMIN = IBBCSD + LBBCSDWORKMIN - 1
! 302: RWORK(1) = LRWORKOPT
! 303: *
! 304: * Complex workspace
! 305: *
! 306: ITAUP1 = 2
! 307: ITAUP2 = ITAUP1 + MAX( 1, P )
! 308: ITAUQ1 = ITAUP2 + MAX( 1, M - P )
! 309: ITAUQ2 = ITAUQ1 + MAX( 1, Q )
! 310: IORGQR = ITAUQ2 + MAX( 1, M - Q )
! 311: CALL ZUNGQR( M-Q, M-Q, M-Q, 0, MAX(1,M-Q), 0, WORK, -1,
! 312: $ CHILDINFO )
! 313: LORGQRWORKOPT = INT( WORK(1) )
! 314: LORGQRWORKMIN = MAX( 1, M - Q )
! 315: IORGLQ = ITAUQ2 + MAX( 1, M - Q )
! 316: CALL ZUNGLQ( M-Q, M-Q, M-Q, 0, MAX(1,M-Q), 0, WORK, -1,
! 317: $ CHILDINFO )
! 318: LORGLQWORKOPT = INT( WORK(1) )
! 319: LORGLQWORKMIN = MAX( 1, M - Q )
! 320: IORBDB = ITAUQ2 + MAX( 1, M - Q )
! 321: CALL ZUNBDB( TRANS, SIGNS, M, P, Q, X11, LDX11, X12, LDX12,
! 322: $ X21, LDX21, X22, LDX22, 0, 0, 0, 0, 0, 0, WORK,
! 323: $ -1, CHILDINFO )
! 324: LORBDBWORKOPT = INT( WORK(1) )
! 325: LORBDBWORKMIN = LORBDBWORKOPT
! 326: LWORKOPT = MAX( IORGQR + LORGQRWORKOPT, IORGLQ + LORGLQWORKOPT,
! 327: $ IORBDB + LORBDBWORKOPT ) - 1
! 328: LWORKMIN = MAX( IORGQR + LORGQRWORKMIN, IORGLQ + LORGLQWORKMIN,
! 329: $ IORBDB + LORBDBWORKMIN ) - 1
! 330: WORK(1) = LWORKOPT
! 331: *
! 332: IF( LWORK .LT. LWORKMIN
! 333: $ .AND. .NOT. ( LQUERY .OR. LRQUERY ) ) THEN
! 334: INFO = -22
! 335: ELSE IF( LRWORK .LT. LRWORKMIN
! 336: $ .AND. .NOT. ( LQUERY .OR. LRQUERY ) ) THEN
! 337: INFO = -24
! 338: ELSE
! 339: LORGQRWORK = LWORK - IORGQR + 1
! 340: LORGLQWORK = LWORK - IORGLQ + 1
! 341: LORBDBWORK = LWORK - IORBDB + 1
! 342: LBBCSDWORK = LRWORK - IBBCSD + 1
! 343: END IF
! 344: END IF
! 345: *
! 346: * Abort if any illegal arguments
! 347: *
! 348: IF( INFO .NE. 0 ) THEN
! 349: CALL XERBLA( 'ZUNCSD', -INFO )
! 350: RETURN
! 351: ELSE IF( LQUERY .OR. LRQUERY ) THEN
! 352: RETURN
! 353: END IF
! 354: *
! 355: * Transform to bidiagonal block form
! 356: *
! 357: CALL ZUNBDB( TRANS, SIGNS, M, P, Q, X11, LDX11, X12, LDX12, X21,
! 358: $ LDX21, X22, LDX22, THETA, RWORK(IPHI), WORK(ITAUP1),
! 359: $ WORK(ITAUP2), WORK(ITAUQ1), WORK(ITAUQ2),
! 360: $ WORK(IORBDB), LORBDBWORK, CHILDINFO )
! 361: *
! 362: * Accumulate Householder reflectors
! 363: *
! 364: IF( COLMAJOR ) THEN
! 365: IF( WANTU1 .AND. P .GT. 0 ) THEN
! 366: CALL ZLACPY( 'L', P, Q, X11, LDX11, U1, LDU1 )
! 367: CALL ZUNGQR( P, P, Q, U1, LDU1, WORK(ITAUP1), WORK(IORGQR),
! 368: $ LORGQRWORK, INFO)
! 369: END IF
! 370: IF( WANTU2 .AND. M-P .GT. 0 ) THEN
! 371: CALL ZLACPY( 'L', M-P, Q, X21, LDX21, U2, LDU2 )
! 372: CALL ZUNGQR( M-P, M-P, Q, U2, LDU2, WORK(ITAUP2),
! 373: $ WORK(IORGQR), LORGQRWORK, INFO )
! 374: END IF
! 375: IF( WANTV1T .AND. Q .GT. 0 ) THEN
! 376: CALL ZLACPY( 'U', Q-1, Q-1, X11(1,2), LDX11, V1T(2,2),
! 377: $ LDV1T )
! 378: V1T(1, 1) = ONE
! 379: DO J = 2, Q
! 380: V1T(1,J) = ZERO
! 381: V1T(J,1) = ZERO
! 382: END DO
! 383: CALL ZUNGLQ( Q-1, Q-1, Q-1, V1T(2,2), LDV1T, WORK(ITAUQ1),
! 384: $ WORK(IORGLQ), LORGLQWORK, INFO )
! 385: END IF
! 386: IF( WANTV2T .AND. M-Q .GT. 0 ) THEN
! 387: CALL ZLACPY( 'U', P, M-Q, X12, LDX12, V2T, LDV2T )
! 388: CALL ZLACPY( 'U', M-P-Q, M-P-Q, X22(Q+1,P+1), LDX22,
! 389: $ V2T(P+1,P+1), LDV2T )
! 390: CALL ZUNGLQ( M-Q, M-Q, M-Q, V2T, LDV2T, WORK(ITAUQ2),
! 391: $ WORK(IORGLQ), LORGLQWORK, INFO )
! 392: END IF
! 393: ELSE
! 394: IF( WANTU1 .AND. P .GT. 0 ) THEN
! 395: CALL ZLACPY( 'U', Q, P, X11, LDX11, U1, LDU1 )
! 396: CALL ZUNGLQ( P, P, Q, U1, LDU1, WORK(ITAUP1), WORK(IORGLQ),
! 397: $ LORGLQWORK, INFO)
! 398: END IF
! 399: IF( WANTU2 .AND. M-P .GT. 0 ) THEN
! 400: CALL ZLACPY( 'U', Q, M-P, X21, LDX21, U2, LDU2 )
! 401: CALL ZUNGLQ( M-P, M-P, Q, U2, LDU2, WORK(ITAUP2),
! 402: $ WORK(IORGLQ), LORGLQWORK, INFO )
! 403: END IF
! 404: IF( WANTV1T .AND. Q .GT. 0 ) THEN
! 405: CALL ZLACPY( 'L', Q-1, Q-1, X11(2,1), LDX11, V1T(2,2),
! 406: $ LDV1T )
! 407: V1T(1, 1) = ONE
! 408: DO J = 2, Q
! 409: V1T(1,J) = ZERO
! 410: V1T(J,1) = ZERO
! 411: END DO
! 412: CALL ZUNGQR( Q-1, Q-1, Q-1, V1T(2,2), LDV1T, WORK(ITAUQ1),
! 413: $ WORK(IORGQR), LORGQRWORK, INFO )
! 414: END IF
! 415: IF( WANTV2T .AND. M-Q .GT. 0 ) THEN
! 416: CALL ZLACPY( 'L', M-Q, P, X12, LDX12, V2T, LDV2T )
! 417: CALL ZLACPY( 'L', M-P-Q, M-P-Q, X22(P+1,Q+1), LDX22,
! 418: $ V2T(P+1,P+1), LDV2T )
! 419: CALL ZUNGQR( M-Q, M-Q, M-Q, V2T, LDV2T, WORK(ITAUQ2),
! 420: $ WORK(IORGQR), LORGQRWORK, INFO )
! 421: END IF
! 422: END IF
! 423: *
! 424: * Compute the CSD of the matrix in bidiagonal-block form
! 425: *
! 426: CALL ZBBCSD( JOBU1, JOBU2, JOBV1T, JOBV2T, TRANS, M, P, Q, THETA,
! 427: $ RWORK(IPHI), U1, LDU1, U2, LDU2, V1T, LDV1T, V2T,
! 428: $ LDV2T, RWORK(IB11D), RWORK(IB11E), RWORK(IB12D),
! 429: $ RWORK(IB12E), RWORK(IB21D), RWORK(IB21E),
! 430: $ RWORK(IB22D), RWORK(IB22E), RWORK(IBBCSD),
! 431: $ LBBCSDWORK, INFO )
! 432: *
! 433: * Permute rows and columns to place identity submatrices in top-
! 434: * left corner of (1,1)-block and/or bottom-right corner of (1,2)-
! 435: * block and/or bottom-right corner of (2,1)-block and/or top-left
! 436: * corner of (2,2)-block
! 437: *
! 438: IF( Q .GT. 0 .AND. WANTU2 ) THEN
! 439: DO I = 1, Q
! 440: IWORK(I) = M - P - Q + I
! 441: END DO
! 442: DO I = Q + 1, M - P
! 443: IWORK(I) = I - Q
! 444: END DO
! 445: IF( COLMAJOR ) THEN
! 446: CALL ZLAPMT( .FALSE., M-P, M-P, U2, LDU2, IWORK )
! 447: ELSE
! 448: CALL ZLAPMR( .FALSE., M-P, M-P, U2, LDU2, IWORK )
! 449: END IF
! 450: END IF
! 451: IF( M .GT. 0 .AND. WANTV2T ) THEN
! 452: DO I = 1, P
! 453: IWORK(I) = M - P - Q + I
! 454: END DO
! 455: DO I = P + 1, M - Q
! 456: IWORK(I) = I - P
! 457: END DO
! 458: IF( .NOT. COLMAJOR ) THEN
! 459: CALL ZLAPMT( .FALSE., M-Q, M-Q, V2T, LDV2T, IWORK )
! 460: ELSE
! 461: CALL ZLAPMR( .FALSE., M-Q, M-Q, V2T, LDV2T, IWORK )
! 462: END IF
! 463: END IF
! 464: *
! 465: RETURN
! 466: *
! 467: * End ZUNCSD
! 468: *
! 469: END
! 470:
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