slatmt.c

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/* slatmt.f -- translated by f2c (version 20061008).
   You must link the resulting object file with libf2c:
        on Microsoft Windows system, link with libf2c.lib;
        on Linux or Unix systems, link with .../path/to/libf2c.a -lm
        or, if you install libf2c.a in a standard place, with -lf2c -lm
        -- in that order, at the end of the command line, as in
                cc *.o -lf2c -lm
        Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,

                http://www.netlib.org/f2c/libf2c.zip
*/

#include "f2c.h"
#include "blaswrap.h"

/* Table of constant values */

static integer c__1 = 1;
static real c_b22 = 0.f;
static logical c_true = TRUE_;
static logical c_false = FALSE_;

/* Subroutine */ int slatmt_(integer *m, integer *n, char *dist, integer *
        iseed, char *sym, real *d__, integer *mode, real *cond, real *dmax__, 
        integer *rank, integer *kl, integer *ku, char *pack, real *a, integer 
        *lda, real *work, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5, i__6;
    real r__1, r__2, r__3;
    logical L__1;

    /* Builtin functions */
    double cos(doublereal), sin(doublereal);

    /* Local variables */
    real c__;
    integer i__, j, k;
    real s;
    integer ic, jc, nc, il, ir, jr, mr, ir1, ir2, jch, llb, jkl, jku, uub, 
            ilda, icol;
    real temp;
    integer irow, isym;
    real alpha, angle;
    integer ipack, ioffg;
    extern logical lsame_(char *, char *);
    integer iinfo;
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
    integer idist, mnmin, iskew;
    real extra, dummy;
    extern /* Subroutine */ int scopy_(integer *, real *, integer *, real *, 
            integer *), slatm7_(integer *, real *, integer *, integer *, 
            integer *, real *, integer *, integer *, integer *);
    integer iendch, ipackg;
    extern /* Subroutine */ int slagge_(integer *, integer *, integer *, 
            integer *, real *, real *, integer *, integer *, real *, integer *
);
    integer minlda;
    extern /* Subroutine */ int xerbla_(char *, integer *);
    extern doublereal slarnd_(integer *, integer *);
    integer ioffst, irsign;
    logical givens, iltemp;
    extern /* Subroutine */ int slartg_(real *, real *, real *, real *, real *
), slaset_(char *, integer *, integer *, real *, real *, real *, 
            integer *), slagsy_(integer *, integer *, real *, real *, 
            integer *, integer *, real *, integer *), slarot_(logical *, 
            logical *, logical *, integer *, real *, real *, real *, integer *
, real *, real *);
    logical ilextr, topdwn;
    integer isympk;


/*  -- LAPACK test routine (version 3.1) -- */
/*     Craig Lucas, University of Manchester / NAG Ltd. */
/*     October, 2008 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*     SLATMT generates random matrices with specified singular values */
/*     (or symmetric/hermitian with specified eigenvalues) */
/*     for testing LAPACK programs. */

/*     SLATMT operates by applying the following sequence of */
/*     operations: */

/*       Set the diagonal to D, where D may be input or */
/*          computed according to MODE, COND, DMAX, and SYM */
/*          as described below. */

/*       Generate a matrix with the appropriate band structure, by one */
/*          of two methods: */

/*       Method A: */
/*           Generate a dense M x N matrix by multiplying D on the left */
/*               and the right by random unitary matrices, then: */

/*           Reduce the bandwidth according to KL and KU, using */
/*           Householder transformations. */

/*       Method B: */
/*           Convert the bandwidth-0 (i.e., diagonal) matrix to a */
/*               bandwidth-1 matrix using Givens rotations, "chasing" */
/*               out-of-band elements back, much as in QR; then */
/*               convert the bandwidth-1 to a bandwidth-2 matrix, etc. */
/*               Note that for reasonably small bandwidths (relative to */
/*               M and N) this requires less storage, as a dense matrix */
/*               is not generated.  Also, for symmetric matrices, only */
/*               one triangle is generated. */

/*       Method A is chosen if the bandwidth is a large fraction of the */
/*           order of the matrix, and LDA is at least M (so a dense */
/*           matrix can be stored.)  Method B is chosen if the bandwidth */
/*           is small (< 1/2 N for symmetric, < .3 N+M for */
/*           non-symmetric), or LDA is less than M and not less than the */
/*           bandwidth. */

/*       Pack the matrix if desired. Options specified by PACK are: */
/*          no packing */
/*          zero out upper half (if symmetric) */
/*          zero out lower half (if symmetric) */
/*          store the upper half columnwise (if symmetric or upper */
/*                triangular) */
/*          store the lower half columnwise (if symmetric or lower */
/*                triangular) */
/*          store the lower triangle in banded format (if symmetric */
/*                or lower triangular) */
/*          store the upper triangle in banded format (if symmetric */
/*                or upper triangular) */
/*          store the entire matrix in banded format */
/*       If Method B is chosen, and band format is specified, then the */
/*          matrix will be generated in the band format, so no repacking */
/*          will be necessary. */

/*  Arguments */
/*  ========= */

/*  M      - INTEGER */
/*           The number of rows of A. Not modified. */

/*  N      - INTEGER */
/*           The number of columns of A. Not modified. */

/*  DIST   - CHARACTER*1 */
/*           On entry, DIST specifies the type of distribution to be used */
/*           to generate the random eigen-/singular values. */
/*           'U' => UNIFORM( 0, 1 )  ( 'U' for uniform ) */
/*           'S' => UNIFORM( -1, 1 ) ( 'S' for symmetric ) */
/*           'N' => NORMAL( 0, 1 )   ( 'N' for normal ) */
/*           Not modified. */

/*  ISEED  - INTEGER array, dimension ( 4 ) */
/*           On entry ISEED specifies the seed of the random number */
/*           generator. They should lie between 0 and 4095 inclusive, */
/*           and ISEED(4) should be odd. The random number generator */
/*           uses a linear congruential sequence limited to small */
/*           integers, and so should produce machine independent */
/*           random numbers. The values of ISEED are changed on */
/*           exit, and can be used in the next call to SLATMT */
/*           to continue the same random number sequence. */
/*           Changed on exit. */

/*  SYM    - CHARACTER*1 */
/*           If SYM='S' or 'H', the generated matrix is symmetric, with */
/*             eigenvalues specified by D, COND, MODE, and DMAX; they */
/*             may be positive, negative, or zero. */
/*           If SYM='P', the generated matrix is symmetric, with */
/*             eigenvalues (= singular values) specified by D, COND, */
/*             MODE, and DMAX; they will not be negative. */
/*           If SYM='N', the generated matrix is nonsymmetric, with */
/*             singular values specified by D, COND, MODE, and DMAX; */
/*             they will not be negative. */
/*           Not modified. */

/*  D      - REAL array, dimension ( MIN( M , N ) ) */
/*           This array is used to specify the singular values or */
/*           eigenvalues of A (see SYM, above.)  If MODE=0, then D is */
/*           assumed to contain the singular/eigenvalues, otherwise */
/*           they will be computed according to MODE, COND, and DMAX, */
/*           and placed in D. */
/*           Modified if MODE is nonzero. */

/*  MODE   - INTEGER */
/*           On entry this describes how the singular/eigenvalues are to */
/*           be specified: */
/*           MODE = 0 means use D as input */

/*           MODE = 1 sets D(1)=1 and D(2:RANK)=1.0/COND */
/*           MODE = 2 sets D(1:RANK-1)=1 and D(RANK)=1.0/COND */
/*           MODE = 3 sets D(I)=COND**(-(I-1)/(RANK-1)) */

/*           MODE = 4 sets D(i)=1 - (i-1)/(N-1)*(1 - 1/COND) */
/*           MODE = 5 sets D to random numbers in the range */
/*                    ( 1/COND , 1 ) such that their logarithms */
/*                    are uniformly distributed. */
/*           MODE = 6 set D to random numbers from same distribution */
/*                    as the rest of the matrix. */
/*           MODE < 0 has the same meaning as ABS(MODE), except that */
/*              the order of the elements of D is reversed. */
/*           Thus if MODE is positive, D has entries ranging from */
/*              1 to 1/COND, if negative, from 1/COND to 1, */
/*           If SYM='S' or 'H', and MODE is neither 0, 6, nor -6, then */
/*              the elements of D will also be multiplied by a random */
/*              sign (i.e., +1 or -1.) */
/*           Not modified. */

/*  COND   - REAL */
/*           On entry, this is used as described under MODE above. */
/*           If used, it must be >= 1. Not modified. */

/*  DMAX   - REAL */
/*           If MODE is neither -6, 0 nor 6, the contents of D, as */
/*           computed according to MODE and COND, will be scaled by */
/*           DMAX / max(abs(D(i))); thus, the maximum absolute eigen- or */
/*           singular value (which is to say the norm) will be abs(DMAX). */
/*           Note that DMAX need not be positive: if DMAX is negative */
/*           (or zero), D will be scaled by a negative number (or zero). */
/*           Not modified. */

/*  RANK   - INTEGER */
/*           The rank of matrix to be generated for modes 1,2,3 only. */
/*           D( RANK+1:N ) = 0. */
/*           Not modified. */

/*  KL     - INTEGER */
/*           This specifies the lower bandwidth of the  matrix. For */
/*           example, KL=0 implies upper triangular, KL=1 implies upper */
/*           Hessenberg, and KL being at least M-1 means that the matrix */
/*           has full lower bandwidth.  KL must equal KU if the matrix */
/*           is symmetric. */
/*           Not modified. */

/*  KU     - INTEGER */
/*           This specifies the upper bandwidth of the  matrix. For */
/*           example, KU=0 implies lower triangular, KU=1 implies lower */
/*           Hessenberg, and KU being at least N-1 means that the matrix */
/*           has full upper bandwidth.  KL must equal KU if the matrix */
/*           is symmetric. */
/*           Not modified. */

/*  PACK   - CHARACTER*1 */
/*           This specifies packing of matrix as follows: */
/*           'N' => no packing */
/*           'U' => zero out all subdiagonal entries (if symmetric) */
/*           'L' => zero out all superdiagonal entries (if symmetric) */
/*           'C' => store the upper triangle columnwise */
/*                  (only if the matrix is symmetric or upper triangular) */
/*           'R' => store the lower triangle columnwise */
/*                  (only if the matrix is symmetric or lower triangular) */
/*           'B' => store the lower triangle in band storage scheme */
/*                  (only if matrix symmetric or lower triangular) */
/*           'Q' => store the upper triangle in band storage scheme */
/*                  (only if matrix symmetric or upper triangular) */
/*           'Z' => store the entire matrix in band storage scheme */
/*                      (pivoting can be provided for by using this */
/*                      option to store A in the trailing rows of */
/*                      the allocated storage) */

/*           Using these options, the various LAPACK packed and banded */
/*           storage schemes can be obtained: */
/*           GB               - use 'Z' */
/*           PB, SB or TB     - use 'B' or 'Q' */
/*           PP, SP or TP     - use 'C' or 'R' */

/*           If two calls to SLATMT differ only in the PACK parameter, */
/*           they will generate mathematically equivalent matrices. */
/*           Not modified. */

/*  A      - REAL array, dimension ( LDA, N ) */
/*           On exit A is the desired test matrix.  A is first generated */
/*           in full (unpacked) form, and then packed, if so specified */
/*           by PACK.  Thus, the first M elements of the first N */
/*           columns will always be modified.  If PACK specifies a */
/*           packed or banded storage scheme, all LDA elements of the */
/*           first N columns will be modified; the elements of the */
/*           array which do not correspond to elements of the generated */
/*           matrix are set to zero. */
/*           Modified. */

/*  LDA    - INTEGER */
/*           LDA specifies the first dimension of A as declared in the */
/*           calling program.  If PACK='N', 'U', 'L', 'C', or 'R', then */
/*           LDA must be at least M.  If PACK='B' or 'Q', then LDA must */
/*           be at least MIN( KL, M-1) (which is equal to MIN(KU,N-1)). */
/*           If PACK='Z', LDA must be large enough to hold the packed */
/*           array: MIN( KU, N-1) + MIN( KL, M-1) + 1. */
/*           Not modified. */

/*  WORK   - REAL array, dimension ( 3*MAX( N , M ) ) */
/*           Workspace. */
/*           Modified. */

/*  INFO   - INTEGER */
/*           Error code.  On exit, INFO will be set to one of the */
/*           following values: */
/*             0 => normal return */
/*            -1 => M negative or unequal to N and SYM='S', 'H', or 'P' */
/*            -2 => N negative */
/*            -3 => DIST illegal string */
/*            -5 => SYM illegal string */
/*            -7 => MODE not in range -6 to 6 */
/*            -8 => COND less than 1.0, and MODE neither -6, 0 nor 6 */
/*           -10 => KL negative */
/*           -11 => KU negative, or SYM='S' or 'H' and KU not equal to KL */
/*           -12 => PACK illegal string, or PACK='U' or 'L', and SYM='N'; */
/*                  or PACK='C' or 'Q' and SYM='N' and KL is not zero; */
/*                  or PACK='R' or 'B' and SYM='N' and KU is not zero; */
/*                  or PACK='U', 'L', 'C', 'R', 'B', or 'Q', and M is not */
/*                  N. */
/*           -14 => LDA is less than M, or PACK='Z' and LDA is less than */
/*                  MIN(KU,N-1) + MIN(KL,M-1) + 1. */
/*            1  => Error return from SLATM7 */
/*            2  => Cannot scale to DMAX (max. sing. value is 0) */
/*            3  => Error return from SLAGGE or SLAGSY */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     1)      Decode and Test the input parameters. */
/*             Initialize flags & seed. */

    /* Parameter adjustments */
    --iseed;
    --d__;
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --work;

    /* Function Body */
    *info = 0;

/*     Quick return if possible */

    if (*m == 0 || *n == 0) {
        return 0;
    }

/*     Decode DIST */

    if (lsame_(dist, "U")) {
        idist = 1;
    } else if (lsame_(dist, "S")) {
        idist = 2;
    } else if (lsame_(dist, "N")) {
        idist = 3;
    } else {
        idist = -1;
    }

/*     Decode SYM */

    if (lsame_(sym, "N")) {
        isym = 1;
        irsign = 0;
    } else if (lsame_(sym, "P")) {
        isym = 2;
        irsign = 0;
    } else if (lsame_(sym, "S")) {
        isym = 2;
        irsign = 1;
    } else if (lsame_(sym, "H")) {
        isym = 2;
        irsign = 1;
    } else {
        isym = -1;
    }

/*     Decode PACK */

    isympk = 0;
    if (lsame_(pack, "N")) {
        ipack = 0;
    } else if (lsame_(pack, "U")) {
        ipack = 1;
        isympk = 1;
    } else if (lsame_(pack, "L")) {
        ipack = 2;
        isympk = 1;
    } else if (lsame_(pack, "C")) {
        ipack = 3;
        isympk = 2;
    } else if (lsame_(pack, "R")) {
        ipack = 4;
        isympk = 3;
    } else if (lsame_(pack, "B")) {
        ipack = 5;
        isympk = 3;
    } else if (lsame_(pack, "Q")) {
        ipack = 6;
        isympk = 2;
    } else if (lsame_(pack, "Z")) {
        ipack = 7;
    } else {
        ipack = -1;
    }

/*     Set certain internal parameters */

    mnmin = min(*m,*n);
/* Computing MIN */
    i__1 = *kl, i__2 = *m - 1;
    llb = min(i__1,i__2);
/* Computing MIN */
    i__1 = *ku, i__2 = *n - 1;
    uub = min(i__1,i__2);
/* Computing MIN */
    i__1 = *m, i__2 = *n + llb;
    mr = min(i__1,i__2);
/* Computing MIN */
    i__1 = *n, i__2 = *m + uub;
    nc = min(i__1,i__2);

    if (ipack == 5 || ipack == 6) {
        minlda = uub + 1;
    } else if (ipack == 7) {
        minlda = llb + uub + 1;
    } else {
        minlda = *m;
    }

/*     Use Givens rotation method if bandwidth small enough, */
/*     or if LDA is too small to store the matrix unpacked. */

    givens = FALSE_;
    if (isym == 1) {
/* Computing MAX */
        i__1 = 1, i__2 = mr + nc;
        if ((real) (llb + uub) < (real) max(i__1,i__2) * .3f) {
            givens = TRUE_;
        }
    } else {
        if (llb << 1 < *m) {
            givens = TRUE_;
        }
    }
    if (*lda < *m && *lda >= minlda) {
        givens = TRUE_;
    }

/*     Set INFO if an error */

    if (*m < 0) {
        *info = -1;
    } else if (*m != *n && isym != 1) {
        *info = -1;
    } else if (*n < 0) {
        *info = -2;
    } else if (idist == -1) {
        *info = -3;
    } else if (isym == -1) {
        *info = -5;
    } else if (abs(*mode) > 6) {
        *info = -7;
    } else if (*mode != 0 && abs(*mode) != 6 && *cond < 1.f) {
        *info = -8;
    } else if (*kl < 0) {
        *info = -10;
    } else if (*ku < 0 || isym != 1 && *kl != *ku) {
        *info = -11;
    } else if (ipack == -1 || isympk == 1 && isym == 1 || isympk == 2 && isym 
            == 1 && *kl > 0 || isympk == 3 && isym == 1 && *ku > 0 || isympk 
            != 0 && *m != *n) {
        *info = -12;
    } else if (*lda < max(1,minlda)) {
        *info = -14;
    }

    if (*info != 0) {
        i__1 = -(*info);
        xerbla_("SLATMT", &i__1);
        return 0;
    }

/*     Initialize random number generator */

    for (i__ = 1; i__ <= 4; ++i__) {
        iseed[i__] = (i__1 = iseed[i__], abs(i__1)) % 4096;
/* L100: */
    }

    if (iseed[4] % 2 != 1) {
        ++iseed[4];
    }

/*     2)      Set up D  if indicated. */

/*             Compute D according to COND and MODE */

    slatm7_(mode, cond, &irsign, &idist, &iseed[1], &d__[1], &mnmin, rank, &
            iinfo);
    if (iinfo != 0) {
        *info = 1;
        return 0;
    }

/*     Choose Top-Down if D is (apparently) increasing, */
/*     Bottom-Up if D is (apparently) decreasing. */

    if (dabs(d__[1]) <= (r__1 = d__[*rank], dabs(r__1))) {
        topdwn = TRUE_;
    } else {
        topdwn = FALSE_;
    }

    if (*mode != 0 && abs(*mode) != 6) {

/*        Scale by DMAX */

        temp = dabs(d__[1]);
        i__1 = *rank;
        for (i__ = 2; i__ <= i__1; ++i__) {
/* Computing MAX */
            r__2 = temp, r__3 = (r__1 = d__[i__], dabs(r__1));
            temp = dmax(r__2,r__3);
/* L110: */
        }

        if (temp > 0.f) {
            alpha = *dmax__ / temp;
        } else {
            *info = 2;
            return 0;
        }

        sscal_(rank, &alpha, &d__[1], &c__1);

    }

/*     3)      Generate Banded Matrix using Givens rotations. */
/*             Also the special case of UUB=LLB=0 */

/*               Compute Addressing constants to cover all */
/*               storage formats.  Whether GE, SY, GB, or SB, */
/*               upper or lower triangle or both, */
/*               the (i,j)-th element is in */
/*               A( i - ISKEW*j + IOFFST, j ) */

    if (ipack > 4) {
        ilda = *lda - 1;
        iskew = 1;
        if (ipack > 5) {
            ioffst = uub + 1;
        } else {
            ioffst = 1;
        }
    } else {
        ilda = *lda;
        iskew = 0;
        ioffst = 0;
    }

/*     IPACKG is the format that the matrix is generated in. If this is */
/*     different from IPACK, then the matrix must be repacked at the */
/*     end.  It also signals how to compute the norm, for scaling. */

    ipackg = 0;
    slaset_("Full", lda, n, &c_b22, &c_b22, &a[a_offset], lda);

/*     Diagonal Matrix -- We are done, unless it */
/*     is to be stored SP/PP/TP (PACK='R' or 'C') */

    if (llb == 0 && uub == 0) {
        i__1 = ilda + 1;
        scopy_(&mnmin, &d__[1], &c__1, &a[1 - iskew + ioffst + a_dim1], &i__1)
                ;
        if (ipack <= 2 || ipack >= 5) {
            ipackg = ipack;
        }

    } else if (givens) {

/*        Check whether to use Givens rotations, */
/*        Householder transformations, or nothing. */

        if (isym == 1) {

/*           Non-symmetric -- A = U D V */

            if (ipack > 4) {
                ipackg = ipack;
            } else {
                ipackg = 0;
            }

            i__1 = ilda + 1;
            scopy_(&mnmin, &d__[1], &c__1, &a[1 - iskew + ioffst + a_dim1], &
                    i__1);

            if (topdwn) {
                jkl = 0;
                i__1 = uub;
                for (jku = 1; jku <= i__1; ++jku) {

/*                 Transform from bandwidth JKL, JKU-1 to JKL, JKU */

/*                 Last row actually rotated is M */
/*                 Last column actually rotated is MIN( M+JKU, N ) */

/* Computing MIN */
                    i__3 = *m + jku;
                    i__2 = min(i__3,*n) + jkl - 1;
                    for (jr = 1; jr <= i__2; ++jr) {
                        extra = 0.f;
                        angle = slarnd_(&c__1, &iseed[1]) * 
                                6.2831853071795864769252867663f;
                        c__ = cos(angle);
                        s = sin(angle);
/* Computing MAX */
                        i__3 = 1, i__4 = jr - jkl;
                        icol = max(i__3,i__4);
                        if (jr < *m) {
/* Computing MIN */
                            i__3 = *n, i__4 = jr + jku;
                            il = min(i__3,i__4) + 1 - icol;
                            L__1 = jr > jkl;
                            slarot_(&c_true, &L__1, &c_false, &il, &c__, &s, &
                                    a[jr - iskew * icol + ioffst + icol * 
                                    a_dim1], &ilda, &extra, &dummy);
                        }

/*                    Chase "EXTRA" back up */

                        ir = jr;
                        ic = icol;
                        i__3 = -jkl - jku;
                        for (jch = jr - jkl; i__3 < 0 ? jch >= 1 : jch <= 1; 
                                jch += i__3) {
                            if (ir < *m) {
                                slartg_(&a[ir + 1 - iskew * (ic + 1) + ioffst 
                                        + (ic + 1) * a_dim1], &extra, &c__, &
                                        s, &dummy);
                            }
/* Computing MAX */
                            i__4 = 1, i__5 = jch - jku;
                            irow = max(i__4,i__5);
                            il = ir + 2 - irow;
                            temp = 0.f;
                            iltemp = jch > jku;
                            r__1 = -s;
                            slarot_(&c_false, &iltemp, &c_true, &il, &c__, &
                                    r__1, &a[irow - iskew * ic + ioffst + ic *
                                     a_dim1], &ilda, &temp, &extra);
                            if (iltemp) {
                                slartg_(&a[irow + 1 - iskew * (ic + 1) + 
                                        ioffst + (ic + 1) * a_dim1], &temp, &
                                        c__, &s, &dummy);
/* Computing MAX */
                                i__4 = 1, i__5 = jch - jku - jkl;
                                icol = max(i__4,i__5);
                                il = ic + 2 - icol;
                                extra = 0.f;
                                L__1 = jch > jku + jkl;
                                r__1 = -s;
                                slarot_(&c_true, &L__1, &c_true, &il, &c__, &
                                        r__1, &a[irow - iskew * icol + ioffst 
                                        + icol * a_dim1], &ilda, &extra, &
                                        temp);
                                ic = icol;
                                ir = irow;
                            }
/* L120: */
                        }
/* L130: */
                    }
/* L140: */
                }

                jku = uub;
                i__1 = llb;
                for (jkl = 1; jkl <= i__1; ++jkl) {

/*                 Transform from bandwidth JKL-1, JKU to JKL, JKU */

/* Computing MIN */
                    i__3 = *n + jkl;
                    i__2 = min(i__3,*m) + jku - 1;
                    for (jc = 1; jc <= i__2; ++jc) {
                        extra = 0.f;
                        angle = slarnd_(&c__1, &iseed[1]) * 
                                6.2831853071795864769252867663f;
                        c__ = cos(angle);
                        s = sin(angle);
/* Computing MAX */
                        i__3 = 1, i__4 = jc - jku;
                        irow = max(i__3,i__4);
                        if (jc < *n) {
/* Computing MIN */
                            i__3 = *m, i__4 = jc + jkl;
                            il = min(i__3,i__4) + 1 - irow;
                            L__1 = jc > jku;
                            slarot_(&c_false, &L__1, &c_false, &il, &c__, &s, 
                                    &a[irow - iskew * jc + ioffst + jc * 
                                    a_dim1], &ilda, &extra, &dummy);
                        }

/*                    Chase "EXTRA" back up */

                        ic = jc;
                        ir = irow;
                        i__3 = -jkl - jku;
                        for (jch = jc - jku; i__3 < 0 ? jch >= 1 : jch <= 1; 
                                jch += i__3) {
                            if (ic < *n) {
                                slartg_(&a[ir + 1 - iskew * (ic + 1) + ioffst 
                                        + (ic + 1) * a_dim1], &extra, &c__, &
                                        s, &dummy);
                            }
/* Computing MAX */
                            i__4 = 1, i__5 = jch - jkl;
                            icol = max(i__4,i__5);
                            il = ic + 2 - icol;
                            temp = 0.f;
                            iltemp = jch > jkl;
                            r__1 = -s;
                            slarot_(&c_true, &iltemp, &c_true, &il, &c__, &
                                    r__1, &a[ir - iskew * icol + ioffst + 
                                    icol * a_dim1], &ilda, &temp, &extra);
                            if (iltemp) {
                                slartg_(&a[ir + 1 - iskew * (icol + 1) + 
                                        ioffst + (icol + 1) * a_dim1], &temp, 
                                        &c__, &s, &dummy);
/* Computing MAX */
                                i__4 = 1, i__5 = jch - jkl - jku;
                                irow = max(i__4,i__5);
                                il = ir + 2 - irow;
                                extra = 0.f;
                                L__1 = jch > jkl + jku;
                                r__1 = -s;
                                slarot_(&c_false, &L__1, &c_true, &il, &c__, &
                                        r__1, &a[irow - iskew * icol + ioffst 
                                        + icol * a_dim1], &ilda, &extra, &
                                        temp);
                                ic = icol;
                                ir = irow;
                            }
/* L150: */
                        }
/* L160: */
                    }
/* L170: */
                }

            } else {

/*              Bottom-Up -- Start at the bottom right. */

                jkl = 0;
                i__1 = uub;
                for (jku = 1; jku <= i__1; ++jku) {

/*                 Transform from bandwidth JKL, JKU-1 to JKL, JKU */

/*                 First row actually rotated is M */
/*                 First column actually rotated is MIN( M+JKU, N ) */

/* Computing MIN */
                    i__2 = *m, i__3 = *n + jkl;
                    iendch = min(i__2,i__3) - 1;
/* Computing MIN */
                    i__2 = *m + jku;
                    i__3 = 1 - jkl;
                    for (jc = min(i__2,*n) - 1; jc >= i__3; --jc) {
                        extra = 0.f;
                        angle = slarnd_(&c__1, &iseed[1]) * 
                                6.2831853071795864769252867663f;
                        c__ = cos(angle);
                        s = sin(angle);
/* Computing MAX */
                        i__2 = 1, i__4 = jc - jku + 1;
                        irow = max(i__2,i__4);
                        if (jc > 0) {
/* Computing MIN */
                            i__2 = *m, i__4 = jc + jkl + 1;
                            il = min(i__2,i__4) + 1 - irow;
                            L__1 = jc + jkl < *m;
                            slarot_(&c_false, &c_false, &L__1, &il, &c__, &s, 
                                    &a[irow - iskew * jc + ioffst + jc * 
                                    a_dim1], &ilda, &dummy, &extra);
                        }

/*                    Chase "EXTRA" back down */

                        ic = jc;
                        i__2 = iendch;
                        i__4 = jkl + jku;
                        for (jch = jc + jkl; i__4 < 0 ? jch >= i__2 : jch <= 
                                i__2; jch += i__4) {
                            ilextr = ic > 0;
                            if (ilextr) {
                                slartg_(&a[jch - iskew * ic + ioffst + ic * 
                                        a_dim1], &extra, &c__, &s, &dummy);
                            }
                            ic = max(1,ic);
/* Computing MIN */
                            i__5 = *n - 1, i__6 = jch + jku;
                            icol = min(i__5,i__6);
                            iltemp = jch + jku < *n;
                            temp = 0.f;
                            i__5 = icol + 2 - ic;
                            slarot_(&c_true, &ilextr, &iltemp, &i__5, &c__, &
                                    s, &a[jch - iskew * ic + ioffst + ic * 
                                    a_dim1], &ilda, &extra, &temp);
                            if (iltemp) {
                                slartg_(&a[jch - iskew * icol + ioffst + icol 
                                        * a_dim1], &temp, &c__, &s, &dummy);
/* Computing MIN */
                                i__5 = iendch, i__6 = jch + jkl + jku;
                                il = min(i__5,i__6) + 2 - jch;
                                extra = 0.f;
                                L__1 = jch + jkl + jku <= iendch;
                                slarot_(&c_false, &c_true, &L__1, &il, &c__, &
                                        s, &a[jch - iskew * icol + ioffst + 
                                        icol * a_dim1], &ilda, &temp, &extra);
                                ic = icol;
                            }
/* L180: */
                        }
/* L190: */
                    }
/* L200: */
                }

                jku = uub;
                i__1 = llb;
                for (jkl = 1; jkl <= i__1; ++jkl) {

/*                 Transform from bandwidth JKL-1, JKU to JKL, JKU */

/*                 First row actually rotated is MIN( N+JKL, M ) */
/*                 First column actually rotated is N */

/* Computing MIN */
                    i__3 = *n, i__4 = *m + jku;
                    iendch = min(i__3,i__4) - 1;
/* Computing MIN */
                    i__3 = *n + jkl;
                    i__4 = 1 - jku;
                    for (jr = min(i__3,*m) - 1; jr >= i__4; --jr) {
                        extra = 0.f;
                        angle = slarnd_(&c__1, &iseed[1]) * 
                                6.2831853071795864769252867663f;
                        c__ = cos(angle);
                        s = sin(angle);
/* Computing MAX */
                        i__3 = 1, i__2 = jr - jkl + 1;
                        icol = max(i__3,i__2);
                        if (jr > 0) {
/* Computing MIN */
                            i__3 = *n, i__2 = jr + jku + 1;
                            il = min(i__3,i__2) + 1 - icol;
                            L__1 = jr + jku < *n;
                            slarot_(&c_true, &c_false, &L__1, &il, &c__, &s, &
                                    a[jr - iskew * icol + ioffst + icol * 
                                    a_dim1], &ilda, &dummy, &extra);
                        }

/*                    Chase "EXTRA" back down */

                        ir = jr;
                        i__3 = iendch;
                        i__2 = jkl + jku;
                        for (jch = jr + jku; i__2 < 0 ? jch >= i__3 : jch <= 
                                i__3; jch += i__2) {
                            ilextr = ir > 0;
                            if (ilextr) {
                                slartg_(&a[ir - iskew * jch + ioffst + jch * 
                                        a_dim1], &extra, &c__, &s, &dummy);
                            }
                            ir = max(1,ir);
/* Computing MIN */
                            i__5 = *m - 1, i__6 = jch + jkl;
                            irow = min(i__5,i__6);
                            iltemp = jch + jkl < *m;
                            temp = 0.f;
                            i__5 = irow + 2 - ir;
                            slarot_(&c_false, &ilextr, &iltemp, &i__5, &c__, &
                                    s, &a[ir - iskew * jch + ioffst + jch * 
                                    a_dim1], &ilda, &extra, &temp);
                            if (iltemp) {
                                slartg_(&a[irow - iskew * jch + ioffst + jch *
                                         a_dim1], &temp, &c__, &s, &dummy);
/* Computing MIN */
                                i__5 = iendch, i__6 = jch + jkl + jku;
                                il = min(i__5,i__6) + 2 - jch;
                                extra = 0.f;
                                L__1 = jch + jkl + jku <= iendch;
                                slarot_(&c_true, &c_true, &L__1, &il, &c__, &
                                        s, &a[irow - iskew * jch + ioffst + 
                                        jch * a_dim1], &ilda, &temp, &extra);
                                ir = irow;
                            }
/* L210: */
                        }
/* L220: */
                    }
/* L230: */
                }
            }

        } else {

/*           Symmetric -- A = U D U' */

            ipackg = ipack;
            ioffg = ioffst;

            if (topdwn) {

/*              Top-Down -- Generate Upper triangle only */

                if (ipack >= 5) {
                    ipackg = 6;
                    ioffg = uub + 1;
                } else {
                    ipackg = 1;
                }
                i__1 = ilda + 1;
                scopy_(&mnmin, &d__[1], &c__1, &a[1 - iskew + ioffg + a_dim1], 
                         &i__1);

                i__1 = uub;
                for (k = 1; k <= i__1; ++k) {
                    i__4 = *n - 1;
                    for (jc = 1; jc <= i__4; ++jc) {
/* Computing MAX */
                        i__2 = 1, i__3 = jc - k;
                        irow = max(i__2,i__3);
/* Computing MIN */
                        i__2 = jc + 1, i__3 = k + 2;
                        il = min(i__2,i__3);
                        extra = 0.f;
                        temp = a[jc - iskew * (jc + 1) + ioffg + (jc + 1) * 
                                a_dim1];
                        angle = slarnd_(&c__1, &iseed[1]) * 
                                6.2831853071795864769252867663f;
                        c__ = cos(angle);
                        s = sin(angle);
                        L__1 = jc > k;
                        slarot_(&c_false, &L__1, &c_true, &il, &c__, &s, &a[
                                irow - iskew * jc + ioffg + jc * a_dim1], &
                                ilda, &extra, &temp);
/* Computing MIN */
                        i__3 = k, i__5 = *n - jc;
                        i__2 = min(i__3,i__5) + 1;
                        slarot_(&c_true, &c_true, &c_false, &i__2, &c__, &s, &
                                a[(1 - iskew) * jc + ioffg + jc * a_dim1], &
                                ilda, &temp, &dummy);

/*                    Chase EXTRA back up the matrix */

                        icol = jc;
                        i__2 = -k;
                        for (jch = jc - k; i__2 < 0 ? jch >= 1 : jch <= 1; 
                                jch += i__2) {
                            slartg_(&a[jch + 1 - iskew * (icol + 1) + ioffg + 
                                    (icol + 1) * a_dim1], &extra, &c__, &s, &
                                    dummy);
                            temp = a[jch - iskew * (jch + 1) + ioffg + (jch + 
                                    1) * a_dim1];
                            i__3 = k + 2;
                            r__1 = -s;
                            slarot_(&c_true, &c_true, &c_true, &i__3, &c__, &
                                    r__1, &a[(1 - iskew) * jch + ioffg + jch *
                                     a_dim1], &ilda, &temp, &extra);
/* Computing MAX */
                            i__3 = 1, i__5 = jch - k;
                            irow = max(i__3,i__5);
/* Computing MIN */
                            i__3 = jch + 1, i__5 = k + 2;
                            il = min(i__3,i__5);
                            extra = 0.f;
                            L__1 = jch > k;
                            r__1 = -s;
                            slarot_(&c_false, &L__1, &c_true, &il, &c__, &
                                    r__1, &a[irow - iskew * jch + ioffg + jch 
                                    * a_dim1], &ilda, &extra, &temp);
                            icol = jch;
/* L240: */
                        }
/* L250: */
                    }
/* L260: */
                }

/*              If we need lower triangle, copy from upper. Note that */
/*              the order of copying is chosen to work for 'q' -> 'b' */

                if (ipack != ipackg && ipack != 3) {
                    i__1 = *n;
                    for (jc = 1; jc <= i__1; ++jc) {
                        irow = ioffst - iskew * jc;
/* Computing MIN */
                        i__2 = *n, i__3 = jc + uub;
                        i__4 = min(i__2,i__3);
                        for (jr = jc; jr <= i__4; ++jr) {
                            a[jr + irow + jc * a_dim1] = a[jc - iskew * jr + 
                                    ioffg + jr * a_dim1];
/* L270: */
                        }
/* L280: */
                    }
                    if (ipack == 5) {
                        i__1 = *n;
                        for (jc = *n - uub + 1; jc <= i__1; ++jc) {
                            i__4 = uub + 1;
                            for (jr = *n + 2 - jc; jr <= i__4; ++jr) {
                                a[jr + jc * a_dim1] = 0.f;
/* L290: */
                            }
/* L300: */
                        }
                    }
                    if (ipackg == 6) {
                        ipackg = ipack;
                    } else {
                        ipackg = 0;
                    }
                }
            } else {

/*              Bottom-Up -- Generate Lower triangle only */

                if (ipack >= 5) {
                    ipackg = 5;
                    if (ipack == 6) {
                        ioffg = 1;
                    }
                } else {
                    ipackg = 2;
                }
                i__1 = ilda + 1;
                scopy_(&mnmin, &d__[1], &c__1, &a[1 - iskew + ioffg + a_dim1], 
                         &i__1);

                i__1 = uub;
                for (k = 1; k <= i__1; ++k) {
                    for (jc = *n - 1; jc >= 1; --jc) {
/* Computing MIN */
                        i__4 = *n + 1 - jc, i__2 = k + 2;
                        il = min(i__4,i__2);
                        extra = 0.f;
                        temp = a[(1 - iskew) * jc + 1 + ioffg + jc * a_dim1];
                        angle = slarnd_(&c__1, &iseed[1]) * 
                                6.2831853071795864769252867663f;
                        c__ = cos(angle);
                        s = -sin(angle);
                        L__1 = *n - jc > k;
                        slarot_(&c_false, &c_true, &L__1, &il, &c__, &s, &a[(
                                1 - iskew) * jc + ioffg + jc * a_dim1], &ilda, 
                                 &temp, &extra);
/* Computing MAX */
                        i__4 = 1, i__2 = jc - k + 1;
                        icol = max(i__4,i__2);
                        i__4 = jc + 2 - icol;
                        slarot_(&c_true, &c_false, &c_true, &i__4, &c__, &s, &
                                a[jc - iskew * icol + ioffg + icol * a_dim1], 
                                &ilda, &dummy, &temp);

/*                    Chase EXTRA back down the matrix */

                        icol = jc;
                        i__4 = *n - 1;
                        i__2 = k;
                        for (jch = jc + k; i__2 < 0 ? jch >= i__4 : jch <= 
                                i__4; jch += i__2) {
                            slartg_(&a[jch - iskew * icol + ioffg + icol * 
                                    a_dim1], &extra, &c__, &s, &dummy);
                            temp = a[(1 - iskew) * jch + 1 + ioffg + jch * 
                                    a_dim1];
                            i__3 = k + 2;
                            slarot_(&c_true, &c_true, &c_true, &i__3, &c__, &
                                    s, &a[jch - iskew * icol + ioffg + icol * 
                                    a_dim1], &ilda, &extra, &temp);
/* Computing MIN */
                            i__3 = *n + 1 - jch, i__5 = k + 2;
                            il = min(i__3,i__5);
                            extra = 0.f;
                            L__1 = *n - jch > k;
                            slarot_(&c_false, &c_true, &L__1, &il, &c__, &s, &
                                    a[(1 - iskew) * jch + ioffg + jch * 
                                    a_dim1], &ilda, &temp, &extra);
                            icol = jch;
/* L310: */
                        }
/* L320: */
                    }
/* L330: */
                }

/*              If we need upper triangle, copy from lower. Note that */
/*              the order of copying is chosen to work for 'b' -> 'q' */

                if (ipack != ipackg && ipack != 4) {
                    for (jc = *n; jc >= 1; --jc) {
                        irow = ioffst - iskew * jc;
/* Computing MAX */
                        i__2 = 1, i__4 = jc - uub;
                        i__1 = max(i__2,i__4);
                        for (jr = jc; jr >= i__1; --jr) {
                            a[jr + irow + jc * a_dim1] = a[jc - iskew * jr + 
                                    ioffg + jr * a_dim1];
/* L340: */
                        }
/* L350: */
                    }
                    if (ipack == 6) {
                        i__1 = uub;
                        for (jc = 1; jc <= i__1; ++jc) {
                            i__2 = uub + 1 - jc;
                            for (jr = 1; jr <= i__2; ++jr) {
                                a[jr + jc * a_dim1] = 0.f;
/* L360: */
                            }
/* L370: */
                        }
                    }
                    if (ipackg == 5) {
                        ipackg = ipack;
                    } else {
                        ipackg = 0;
                    }
                }
            }
        }

    } else {

/*        4)      Generate Banded Matrix by first */
/*                Rotating by random Unitary matrices, */
/*                then reducing the bandwidth using Householder */
/*                transformations. */

/*                Note: we should get here only if LDA .ge. N */

        if (isym == 1) {

/*           Non-symmetric -- A = U D V */

            slagge_(&mr, &nc, &llb, &uub, &d__[1], &a[a_offset], lda, &iseed[
                    1], &work[1], &iinfo);
        } else {

/*           Symmetric -- A = U D U' */

            slagsy_(m, &llb, &d__[1], &a[a_offset], lda, &iseed[1], &work[1], 
                    &iinfo);

        }
        if (iinfo != 0) {
            *info = 3;
            return 0;
        }
    }

/*     5)      Pack the matrix */

    if (ipack != ipackg) {
        if (ipack == 1) {

/*           'U' -- Upper triangular, not packed */

            i__1 = *m;
            for (j = 1; j <= i__1; ++j) {
                i__2 = *m;
                for (i__ = j + 1; i__ <= i__2; ++i__) {
                    a[i__ + j * a_dim1] = 0.f;
/* L380: */
                }
/* L390: */
            }

        } else if (ipack == 2) {

/*           'L' -- Lower triangular, not packed */

            i__1 = *m;
            for (j = 2; j <= i__1; ++j) {
                i__2 = j - 1;
                for (i__ = 1; i__ <= i__2; ++i__) {
                    a[i__ + j * a_dim1] = 0.f;
/* L400: */
                }
/* L410: */
            }

        } else if (ipack == 3) {

/*           'C' -- Upper triangle packed Columnwise. */

            icol = 1;
            irow = 0;
            i__1 = *m;
            for (j = 1; j <= i__1; ++j) {
                i__2 = j;
                for (i__ = 1; i__ <= i__2; ++i__) {
                    ++irow;
                    if (irow > *lda) {
                        irow = 1;
                        ++icol;
                    }
                    a[irow + icol * a_dim1] = a[i__ + j * a_dim1];
/* L420: */
                }
/* L430: */
            }

        } else if (ipack == 4) {

/*           'R' -- Lower triangle packed Columnwise. */

            icol = 1;
            irow = 0;
            i__1 = *m;
            for (j = 1; j <= i__1; ++j) {
                i__2 = *m;
                for (i__ = j; i__ <= i__2; ++i__) {
                    ++irow;
                    if (irow > *lda) {
                        irow = 1;
                        ++icol;
                    }
                    a[irow + icol * a_dim1] = a[i__ + j * a_dim1];
/* L440: */
                }
/* L450: */
            }

        } else if (ipack >= 5) {

/*           'B' -- The lower triangle is packed as a band matrix. */
/*           'Q' -- The upper triangle is packed as a band matrix. */
/*           'Z' -- The whole matrix is packed as a band matrix. */

            if (ipack == 5) {
                uub = 0;
            }
            if (ipack == 6) {
                llb = 0;
            }

            i__1 = uub;
            for (j = 1; j <= i__1; ++j) {
/* Computing MIN */
                i__2 = j + llb;
                for (i__ = min(i__2,*m); i__ >= 1; --i__) {
                    a[i__ - j + uub + 1 + j * a_dim1] = a[i__ + j * a_dim1];
/* L460: */
                }
/* L470: */
            }

            i__1 = *n;
            for (j = uub + 2; j <= i__1; ++j) {
/* Computing MIN */
                i__4 = j + llb;
                i__2 = min(i__4,*m);
                for (i__ = j - uub; i__ <= i__2; ++i__) {
                    a[i__ - j + uub + 1 + j * a_dim1] = a[i__ + j * a_dim1];
/* L480: */
                }
/* L490: */
            }
        }

/*        If packed, zero out extraneous elements. */

/*        Symmetric/Triangular Packed -- */
/*        zero out everything after A(IROW,ICOL) */

        if (ipack == 3 || ipack == 4) {
            i__1 = *m;
            for (jc = icol; jc <= i__1; ++jc) {
                i__2 = *lda;
                for (jr = irow + 1; jr <= i__2; ++jr) {
                    a[jr + jc * a_dim1] = 0.f;
/* L500: */
                }
                irow = 0;
/* L510: */
            }

        } else if (ipack >= 5) {

/*           Packed Band -- */
/*              1st row is now in A( UUB+2-j, j), zero above it */
/*              m-th row is now in A( M+UUB-j,j), zero below it */
/*              last non-zero diagonal is now in A( UUB+LLB+1,j ), */
/*                 zero below it, too. */

            ir1 = uub + llb + 2;
            ir2 = uub + *m + 2;
            i__1 = *n;
            for (jc = 1; jc <= i__1; ++jc) {
                i__2 = uub + 1 - jc;
                for (jr = 1; jr <= i__2; ++jr) {
                    a[jr + jc * a_dim1] = 0.f;
/* L520: */
                }
/* Computing MAX */
/* Computing MIN */
                i__3 = ir1, i__5 = ir2 - jc;
                i__2 = 1, i__4 = min(i__3,i__5);
                i__6 = *lda;
                for (jr = max(i__2,i__4); jr <= i__6; ++jr) {
                    a[jr + jc * a_dim1] = 0.f;
/* L530: */
                }
/* L540: */
            }
        }
    }

    return 0;

/*     End of SLATMT */

} /* slatmt_ */