/*  -- translated by f2c (version 20100827).
   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"

/* Table of constant values */

static integer c__1 = 1;
static integer c_n1 = -1;
static integer c__3 = 3;
static integer c__2 = 2;
static integer c__0 = 0;

/* Subroutine */ int igraphdlarrd_(char *range, char *order, integer *n, doublereal 
	*vl, doublereal *vu, integer *il, integer *iu, doublereal *gers, 
	doublereal *reltol, doublereal *d__, doublereal *e, doublereal *e2, 
	doublereal *pivmin, integer *nsplit, integer *isplit, integer *m, 
	doublereal *w, doublereal *werr, doublereal *wl, doublereal *wu, 
	integer *iblock, integer *indexw, doublereal *work, integer *iwork, 
	integer *info)
{
    /* System generated locals */
    integer i__1, i__2, i__3;
    doublereal d__1, d__2;

    /* Builtin functions */
    double log(doublereal);

    /* Local variables */
    integer i__, j, ib, ie, je, nb;
    doublereal gl;
    integer im, in;
    doublereal gu;
    integer iw, jee;
    doublereal eps;
    integer nwl;
    doublereal wlu, wul;
    integer nwu;
    doublereal tmp1, tmp2;
    integer iend, jblk, ioff, iout, itmp1, itmp2, jdisc;
    extern logical igraphlsame_(char *, char *);
    integer iinfo;
    doublereal atoli;
    integer iwoff, itmax;
    doublereal wkill, rtoli, uflow, tnorm;
    extern doublereal igraphdlamch_(char *);
    integer ibegin;
    extern /* Subroutine */ int igraphdlaebz_(integer *, integer *, integer *, 
	    integer *, integer *, integer *, doublereal *, doublereal *, 
	    doublereal *, doublereal *, doublereal *, doublereal *, integer *,
	     doublereal *, doublereal *, integer *, integer *, doublereal *, 
	    integer *, integer *);
    integer irange, idiscl, idumma[1];
    extern integer igraphilaenv_(integer *, char *, char *, integer *, integer *, 
	    integer *, integer *, ftnlen, ftnlen);
    integer idiscu;
    logical ncnvrg, toofew;


/*  -- LAPACK auxiliary routine (version 3.3.0)                        --   
    -- LAPACK is a software package provided by Univ. of Tennessee,    --   
    -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--   
       November 2010   


    Purpose   
    =======   

    DLARRD computes the eigenvalues of a symmetric tridiagonal   
    matrix T to suitable accuracy. This is an auxiliary code to be   
    called from DSTEMR.   
    The user may ask for all eigenvalues, all eigenvalues   
    in the half-open interval (VL, VU], or the IL-th through IU-th   
    eigenvalues.   

    To avoid overflow, the matrix must be scaled so that its   
    largest element is no greater than overflow**(1/2) *   
    underflow**(1/4) in absolute value, and for greatest   
    accuracy, it should not be much smaller than that.   

    See W. Kahan "Accurate Eigenvalues of a Symmetric Tridiagonal   
    Matrix", Report CS41, Computer Science Dept., Stanford   
    University, July 21, 1966.   

    Arguments   
    =========   

    RANGE   (input) CHARACTER*1   
            = 'A': ("All")   all eigenvalues will be found.   
            = 'V': ("Value") all eigenvalues in the half-open interval   
                             (VL, VU] will be found.   
            = 'I': ("Index") the IL-th through IU-th eigenvalues (of the   
                             entire matrix) will be found.   

    ORDER   (input) CHARACTER*1   
            = 'B': ("By Block") the eigenvalues will be grouped by   
                                split-off block (see IBLOCK, ISPLIT) and   
                                ordered from smallest to largest within   
                                the block.   
            = 'E': ("Entire matrix")   
                                the eigenvalues for the entire matrix   
                                will be ordered from smallest to   
                                largest.   

    N       (input) INTEGER   
            The order of the tridiagonal matrix T.  N >= 0.   

    VL      (input) DOUBLE PRECISION   
    VU      (input) DOUBLE PRECISION   
            If RANGE='V', the lower and upper bounds of the interval to   
            be searched for eigenvalues.  Eigenvalues less than or equal   
            to VL, or greater than VU, will not be returned.  VL < VU.   
            Not referenced if RANGE = 'A' or 'I'.   

    IL      (input) INTEGER   
    IU      (input) INTEGER   
            If RANGE='I', the indices (in ascending order) of the   
            smallest and largest eigenvalues to be returned.   
            1 <= IL <= IU <= N, if N > 0; IL = 1 and IU = 0 if N = 0.   
            Not referenced if RANGE = 'A' or 'V'.   

    GERS    (input) DOUBLE PRECISION array, dimension (2*N)   
            The N Gerschgorin intervals (the i-th Gerschgorin interval   
            is (GERS(2*i-1), GERS(2*i)).   

    RELTOL  (input) DOUBLE PRECISION   
            The minimum relative width of an interval.  When an interval   
            is narrower than RELTOL times the larger (in   
            magnitude) endpoint, then it is considered to be   
            sufficiently small, i.e., converged.  Note: this should   
            always be at least radix*machine epsilon.   

    D       (input) DOUBLE PRECISION array, dimension (N)   
            The n diagonal elements of the tridiagonal matrix T.   

    E       (input) DOUBLE PRECISION array, dimension (N-1)   
            The (n-1) off-diagonal elements of the tridiagonal matrix T.   

    E2      (input) DOUBLE PRECISION array, dimension (N-1)   
            The (n-1) squared off-diagonal elements of the tridiagonal matrix T.   

    PIVMIN  (input) DOUBLE PRECISION   
            The minimum pivot allowed in the Sturm sequence for T.   

    NSPLIT  (input) INTEGER   
            The number of diagonal blocks in the matrix T.   
            1 <= NSPLIT <= N.   

    ISPLIT  (input) INTEGER array, dimension (N)   
            The splitting points, at which T breaks up into submatrices.   
            The first submatrix consists of rows/columns 1 to ISPLIT(1),   
            the second of rows/columns ISPLIT(1)+1 through ISPLIT(2),   
            etc., and the NSPLIT-th consists of rows/columns   
            ISPLIT(NSPLIT-1)+1 through ISPLIT(NSPLIT)=N.   
            (Only the first NSPLIT elements will actually be used, but   
            since the user cannot know a priori what value NSPLIT will   
            have, N words must be reserved for ISPLIT.)   

    M       (output) INTEGER   
            The actual number of eigenvalues found. 0 <= M <= N.   
            (See also the description of INFO=2,3.)   

    W       (output) DOUBLE PRECISION array, dimension (N)   
            On exit, the first M elements of W will contain the   
            eigenvalue approximations. DLARRD computes an interval   
            I_j = (a_j, b_j] that includes eigenvalue j. The eigenvalue   
            approximation is given as the interval midpoint   
            W(j)= ( a_j + b_j)/2. The corresponding error is bounded by   
            WERR(j) = abs( a_j - b_j)/2   

    WERR    (output) DOUBLE PRECISION array, dimension (N)   
            The error bound on the corresponding eigenvalue approximation   
            in W.   

    WL      (output) DOUBLE PRECISION   
    WU      (output) DOUBLE PRECISION   
            The interval (WL, WU] contains all the wanted eigenvalues.   
            If RANGE='V', then WL=VL and WU=VU.   
            If RANGE='A', then WL and WU are the global Gerschgorin bounds   
                          on the spectrum.   
            If RANGE='I', then WL and WU are computed by DLAEBZ from the   
                          index range specified.   

    IBLOCK  (output) INTEGER array, dimension (N)   
            At each row/column j where E(j) is zero or small, the   
            matrix T is considered to split into a block diagonal   
            matrix.  On exit, if INFO = 0, IBLOCK(i) specifies to which   
            block (from 1 to the number of blocks) the eigenvalue W(i)   
            belongs.  (DLARRD may use the remaining N-M elements as   
            workspace.)   

    INDEXW  (output) INTEGER array, dimension (N)   
            The indices of the eigenvalues within each block (submatrix);   
            for example, INDEXW(i)= j and IBLOCK(i)=k imply that the   
            i-th eigenvalue W(i) is the j-th eigenvalue in block k.   

    WORK    (workspace) DOUBLE PRECISION array, dimension (4*N)   

    IWORK   (workspace) INTEGER array, dimension (3*N)   

    INFO    (output) INTEGER   
            = 0:  successful exit   
            < 0:  if INFO = -i, the i-th argument had an illegal value   
            > 0:  some or all of the eigenvalues failed to converge or   
                  were not computed:   
                  =1 or 3: Bisection failed to converge for some   
                          eigenvalues; these eigenvalues are flagged by a   
                          negative block number.  The effect is that the   
                          eigenvalues may not be as accurate as the   
                          absolute and relative tolerances.  This is   
                          generally caused by unexpectedly inaccurate   
                          arithmetic.   
                  =2 or 3: RANGE='I' only: Not all of the eigenvalues   
                          IL:IU were found.   
                          Effect: M < IU+1-IL   
                          Cause:  non-monotonic arithmetic, causing the   
                                  Sturm sequence to be non-monotonic.   
                          Cure:   recalculate, using RANGE='A', and pick   
                                  out eigenvalues IL:IU.  In some cases,   
                                  increasing the PARAMETER "FUDGE" may   
                                  make things work.   
                  = 4:    RANGE='I', and the Gershgorin interval   
                          initially used was too small.  No eigenvalues   
                          were computed.   
                          Probable cause: your machine has sloppy   
                                          floating-point arithmetic.   
                          Cure: Increase the PARAMETER "FUDGE",   
                                recompile, and try again.   

    Internal Parameters   
    ===================   

    FUDGE   DOUBLE PRECISION, default = 2   
            A "fudge factor" to widen the Gershgorin intervals.  Ideally,   
            a value of 1 should work, but on machines with sloppy   
            arithmetic, this needs to be larger.  The default for   
            publicly released versions should be large enough to handle   
            the worst machine around.  Note that this has no effect   
            on accuracy of the solution.   

    Based on contributions by   
       W. Kahan, University of California, Berkeley, USA   
       Beresford Parlett, University of California, Berkeley, USA   
       Jim Demmel, University of California, Berkeley, USA   
       Inderjit Dhillon, University of Texas, Austin, USA   
       Osni Marques, LBNL/NERSC, USA   
       Christof Voemel, University of California, Berkeley, USA   

    =====================================================================   


       Parameter adjustments */
    --iwork;
    --work;
    --indexw;
    --iblock;
    --werr;
    --w;
    --isplit;
    --e2;
    --e;
    --d__;
    --gers;

    /* Function Body */
    *info = 0;

/*     Decode RANGE */

    if (igraphlsame_(range, "A")) {
	irange = 1;
    } else if (igraphlsame_(range, "V")) {
	irange = 2;
    } else if (igraphlsame_(range, "I")) {
	irange = 3;
    } else {
	irange = 0;
    }

/*     Check for Errors */

    if (irange <= 0) {
	*info = -1;
    } else if (! (igraphlsame_(order, "B") || igraphlsame_(order, 
	    "E"))) {
	*info = -2;
    } else if (*n < 0) {
	*info = -3;
    } else if (irange == 2) {
	if (*vl >= *vu) {
	    *info = -5;
	}
    } else if (irange == 3 && (*il < 1 || *il > max(1,*n))) {
	*info = -6;
    } else if (irange == 3 && (*iu < min(*n,*il) || *iu > *n)) {
	*info = -7;
    }

    if (*info != 0) {
	return 0;
    }
/*     Initialize error flags */
    *info = 0;
    ncnvrg = FALSE_;
    toofew = FALSE_;
/*     Quick return if possible */
    *m = 0;
    if (*n == 0) {
	return 0;
    }
/*     Simplification: */
    if (irange == 3 && *il == 1 && *iu == *n) {
	irange = 1;
    }
/*     Get machine constants */
    eps = igraphdlamch_("P");
    uflow = igraphdlamch_("U");
/*     Special Case when N=1   
       Treat case of 1x1 matrix for quick return */
    if (*n == 1) {
	if (irange == 1 || irange == 2 && d__[1] > *vl && d__[1] <= *vu || 
		irange == 3 && *il == 1 && *iu == 1) {
	    *m = 1;
	    w[1] = d__[1];
/*           The computation error of the eigenvalue is zero */
	    werr[1] = 0.;
	    iblock[1] = 1;
	    indexw[1] = 1;
	}
	return 0;
    }
/*     NB is the minimum vector length for vector bisection, or 0   
       if only scalar is to be done. */
    nb = igraphilaenv_(&c__1, "DSTEBZ", " ", n, &c_n1, &c_n1, &c_n1, (ftnlen)6, (
	    ftnlen)1);
    if (nb <= 1) {
	nb = 0;
    }
/*     Find global spectral radius */
    gl = d__[1];
    gu = d__[1];
    i__1 = *n;
    for (i__ = 1; i__ <= i__1; ++i__) {
/* Computing MIN */
	d__1 = gl, d__2 = gers[(i__ << 1) - 1];
	gl = min(d__1,d__2);
/* Computing MAX */
	d__1 = gu, d__2 = gers[i__ * 2];
	gu = max(d__1,d__2);
/* L5: */
    }
/*     Compute global Gerschgorin bounds and spectral diameter   
   Computing MAX */
    d__1 = abs(gl), d__2 = abs(gu);
    tnorm = max(d__1,d__2);
    gl = gl - tnorm * 2. * eps * *n - *pivmin * 4.;
    gu = gu + tnorm * 2. * eps * *n + *pivmin * 4.;
/*     [JAN/28/2009] remove the line below since SPDIAM variable not use   
       SPDIAM = GU - GL   
       Input arguments for DLAEBZ:   
       The relative tolerance.  An interval (a,b] lies within   
       "relative tolerance" if  b-a < RELTOL*max(|a|,|b|), */
    rtoli = *reltol;
/*     Set the absolute tolerance for interval convergence to zero to force   
       interval convergence based on relative size of the interval.   
       This is dangerous because intervals might not converge when RELTOL is   
       small. But at least a very small number should be selected so that for   
       strongly graded matrices, the code can get relatively accurate   
       eigenvalues. */
    atoli = uflow * 4. + *pivmin * 4.;
    if (irange == 3) {
/*        RANGE='I': Compute an interval containing eigenvalues   
          IL through IU. The initial interval [GL,GU] from the global   
          Gerschgorin bounds GL and GU is refined by DLAEBZ. */
	itmax = (integer) ((log(tnorm + *pivmin) - log(*pivmin)) / log(2.)) + 
		2;
	work[*n + 1] = gl;
	work[*n + 2] = gl;
	work[*n + 3] = gu;
	work[*n + 4] = gu;
	work[*n + 5] = gl;
	work[*n + 6] = gu;
	iwork[1] = -1;
	iwork[2] = -1;
	iwork[3] = *n + 1;
	iwork[4] = *n + 1;
	iwork[5] = *il - 1;
	iwork[6] = *iu;

	igraphdlaebz_(&c__3, &itmax, n, &c__2, &c__2, &nb, &atoli, &rtoli, pivmin, &
		d__[1], &e[1], &e2[1], &iwork[5], &work[*n + 1], &work[*n + 5]
		, &iout, &iwork[1], &w[1], &iblock[1], &iinfo);
	if (iinfo != 0) {
	    *info = iinfo;
	    return 0;
	}
/*        On exit, output intervals may not be ordered by ascending negcount */
	if (iwork[6] == *iu) {
	    *wl = work[*n + 1];
	    wlu = work[*n + 3];
	    nwl = iwork[1];
	    *wu = work[*n + 4];
	    wul = work[*n + 2];
	    nwu = iwork[4];
	} else {
	    *wl = work[*n + 2];
	    wlu = work[*n + 4];
	    nwl = iwork[2];
	    *wu = work[*n + 3];
	    wul = work[*n + 1];
	    nwu = iwork[3];
	}
/*        On exit, the interval [WL, WLU] contains a value with negcount NWL,   
          and [WUL, WU] contains a value with negcount NWU. */
	if (nwl < 0 || nwl >= *n || nwu < 1 || nwu > *n) {
	    *info = 4;
	    return 0;
	}
    } else if (irange == 2) {
	*wl = *vl;
	*wu = *vu;
    } else if (irange == 1) {
	*wl = gl;
	*wu = gu;
    }
/*     Find Eigenvalues -- Loop Over blocks and recompute NWL and NWU.   
       NWL accumulates the number of eigenvalues .le. WL,   
       NWU accumulates the number of eigenvalues .le. WU */
    *m = 0;
    iend = 0;
    *info = 0;
    nwl = 0;
    nwu = 0;

    i__1 = *nsplit;
    for (jblk = 1; jblk <= i__1; ++jblk) {
	ioff = iend;
	ibegin = ioff + 1;
	iend = isplit[jblk];
	in = iend - ioff;

	if (in == 1) {
/*           1x1 block */
	    if (*wl >= d__[ibegin] - *pivmin) {
		++nwl;
	    }
	    if (*wu >= d__[ibegin] - *pivmin) {
		++nwu;
	    }
	    if (irange == 1 || *wl < d__[ibegin] - *pivmin && *wu >= d__[
		    ibegin] - *pivmin) {
		++(*m);
		w[*m] = d__[ibegin];
		werr[*m] = 0.;
/*              The gap for a single block doesn't matter for the later   
                algorithm and is assigned an arbitrary large value */
		iblock[*m] = jblk;
		indexw[*m] = 1;
	    }
/*        Disabled 2x2 case because of a failure on the following matrix   
          RANGE = 'I', IL = IU = 4   
            Original Tridiagonal, d = [   
             -0.150102010615740E+00   
             -0.849897989384260E+00   
             -0.128208148052635E-15   
              0.128257718286320E-15   
            ];   
            e = [   
             -0.357171383266986E+00   
             -0.180411241501588E-15   
             -0.175152352710251E-15   
            ];   

           ELSE IF( IN.EQ.2 ) THEN   
   *           2x2 block   
              DISC = SQRT( (HALF*(D(IBEGIN)-D(IEND)))**2 + E(IBEGIN)**2 )   
              TMP1 = HALF*(D(IBEGIN)+D(IEND))   
              L1 = TMP1 - DISC   
              IF( WL.GE. L1-PIVMIN )   
       $         NWL = NWL + 1   
              IF( WU.GE. L1-PIVMIN )   
       $         NWU = NWU + 1   
              IF( IRANGE.EQ.ALLRNG .OR. ( WL.LT.L1-PIVMIN .AND. WU.GE.   
       $          L1-PIVMIN ) ) THEN   
                 M = M + 1   
                 W( M ) = L1   
   *              The uncertainty of eigenvalues of a 2x2 matrix is very small   
                 WERR( M ) = EPS * ABS( W( M ) ) * TWO   
                 IBLOCK( M ) = JBLK   
                 INDEXW( M ) = 1   
              ENDIF   
              L2 = TMP1 + DISC   
              IF( WL.GE. L2-PIVMIN )   
       $         NWL = NWL + 1   
              IF( WU.GE. L2-PIVMIN )   
       $         NWU = NWU + 1   
              IF( IRANGE.EQ.ALLRNG .OR. ( WL.LT.L2-PIVMIN .AND. WU.GE.   
       $          L2-PIVMIN ) ) THEN   
                 M = M + 1   
                 W( M ) = L2   
   *              The uncertainty of eigenvalues of a 2x2 matrix is very small   
                 WERR( M ) = EPS * ABS( W( M ) ) * TWO   
                 IBLOCK( M ) = JBLK   
                 INDEXW( M ) = 2   
              ENDIF */
	} else {
/*           General Case - block of size IN >= 2   
             Compute local Gerschgorin interval and use it as the initial   
             interval for DLAEBZ */
	    gu = d__[ibegin];
	    gl = d__[ibegin];
	    tmp1 = 0.;
	    i__2 = iend;
	    for (j = ibegin; j <= i__2; ++j) {
/* Computing MIN */
		d__1 = gl, d__2 = gers[(j << 1) - 1];
		gl = min(d__1,d__2);
/* Computing MAX */
		d__1 = gu, d__2 = gers[j * 2];
		gu = max(d__1,d__2);
/* L40: */
	    }
/*           [JAN/28/2009]   
             change SPDIAM by TNORM in lines 2 and 3 thereafter   
             line 1: remove computation of SPDIAM (not useful anymore)   
             SPDIAM = GU - GL   
             GL = GL - FUDGE*SPDIAM*EPS*IN - FUDGE*PIVMIN   
             GU = GU + FUDGE*SPDIAM*EPS*IN + FUDGE*PIVMIN */
	    gl = gl - tnorm * 2. * eps * in - *pivmin * 2.;
	    gu = gu + tnorm * 2. * eps * in + *pivmin * 2.;

	    if (irange > 1) {
		if (gu < *wl) {
/*                 the local block contains none of the wanted eigenvalues */
		    nwl += in;
		    nwu += in;
		    goto L70;
		}
/*              refine search interval if possible, only range (WL,WU] matters */
		gl = max(gl,*wl);
		gu = min(gu,*wu);
		if (gl >= gu) {
		    goto L70;
		}
	    }
/*           Find negcount of initial interval boundaries GL and GU */
	    work[*n + 1] = gl;
	    work[*n + in + 1] = gu;
	    igraphdlaebz_(&c__1, &c__0, &in, &in, &c__1, &nb, &atoli, &rtoli, 
		    pivmin, &d__[ibegin], &e[ibegin], &e2[ibegin], idumma, &
		    work[*n + 1], &work[*n + (in << 1) + 1], &im, &iwork[1], &
		    w[*m + 1], &iblock[*m + 1], &iinfo);
	    if (iinfo != 0) {
		*info = iinfo;
		return 0;
	    }

	    nwl += iwork[1];
	    nwu += iwork[in + 1];
	    iwoff = *m - iwork[1];
/*           Compute Eigenvalues */
	    itmax = (integer) ((log(gu - gl + *pivmin) - log(*pivmin)) / log(
		    2.)) + 2;
	    igraphdlaebz_(&c__2, &itmax, &in, &in, &c__1, &nb, &atoli, &rtoli, 
		    pivmin, &d__[ibegin], &e[ibegin], &e2[ibegin], idumma, &
		    work[*n + 1], &work[*n + (in << 1) + 1], &iout, &iwork[1],
		     &w[*m + 1], &iblock[*m + 1], &iinfo);
	    if (iinfo != 0) {
		*info = iinfo;
		return 0;
	    }

/*           Copy eigenvalues into W and IBLOCK   
             Use -JBLK for block number for unconverged eigenvalues.   
             Loop over the number of output intervals from DLAEBZ */
	    i__2 = iout;
	    for (j = 1; j <= i__2; ++j) {
/*              eigenvalue approximation is middle point of interval */
		tmp1 = (work[j + *n] + work[j + in + *n]) * .5;
/*              semi length of error interval */
		tmp2 = (d__1 = work[j + *n] - work[j + in + *n], abs(d__1)) * 
			.5;
		if (j > iout - iinfo) {
/*                 Flag non-convergence. */
		    ncnvrg = TRUE_;
		    ib = -jblk;
		} else {
		    ib = jblk;
		}
		i__3 = iwork[j + in] + iwoff;
		for (je = iwork[j] + 1 + iwoff; je <= i__3; ++je) {
		    w[je] = tmp1;
		    werr[je] = tmp2;
		    indexw[je] = je - iwoff;
		    iblock[je] = ib;
/* L50: */
		}
/* L60: */
	    }

	    *m += im;
	}
L70:
	;
    }
/*     If RANGE='I', then (WL,WU) contains eigenvalues NWL+1,...,NWU   
       If NWL+1 < IL or NWU > IU, discard extra eigenvalues. */
    if (irange == 3) {
	idiscl = *il - 1 - nwl;
	idiscu = nwu - *iu;

	if (idiscl > 0) {
	    im = 0;
	    i__1 = *m;
	    for (je = 1; je <= i__1; ++je) {
/*              Remove some of the smallest eigenvalues from the left so that   
                at the end IDISCL =0. Move all eigenvalues up to the left. */
		if (w[je] <= wlu && idiscl > 0) {
		    --idiscl;
		} else {
		    ++im;
		    w[im] = w[je];
		    werr[im] = werr[je];
		    indexw[im] = indexw[je];
		    iblock[im] = iblock[je];
		}
/* L80: */
	    }
	    *m = im;
	}
	if (idiscu > 0) {
/*           Remove some of the largest eigenvalues from the right so that   
             at the end IDISCU =0. Move all eigenvalues up to the left. */
	    im = *m + 1;
	    for (je = *m; je >= 1; --je) {
		if (w[je] >= wul && idiscu > 0) {
		    --idiscu;
		} else {
		    --im;
		    w[im] = w[je];
		    werr[im] = werr[je];
		    indexw[im] = indexw[je];
		    iblock[im] = iblock[je];
		}
/* L81: */
	    }
	    jee = 0;
	    i__1 = *m;
	    for (je = im; je <= i__1; ++je) {
		++jee;
		w[jee] = w[je];
		werr[jee] = werr[je];
		indexw[jee] = indexw[je];
		iblock[jee] = iblock[je];
/* L82: */
	    }
	    *m = *m - im + 1;
	}
	if (idiscl > 0 || idiscu > 0) {
/*           Code to deal with effects of bad arithmetic. (If N(w) is   
             monotone non-decreasing, this should never happen.)   
             Some low eigenvalues to be discarded are not in (WL,WLU],   
             or high eigenvalues to be discarded are not in (WUL,WU]   
             so just kill off the smallest IDISCL/largest IDISCU   
             eigenvalues, by marking the corresponding IBLOCK = 0 */
	    if (idiscl > 0) {
		wkill = *wu;
		i__1 = idiscl;
		for (jdisc = 1; jdisc <= i__1; ++jdisc) {
		    iw = 0;
		    i__2 = *m;
		    for (je = 1; je <= i__2; ++je) {
			if (iblock[je] != 0 && (w[je] < wkill || iw == 0)) {
			    iw = je;
			    wkill = w[je];
			}
/* L90: */
		    }
		    iblock[iw] = 0;
/* L100: */
		}
	    }
	    if (idiscu > 0) {
		wkill = *wl;
		i__1 = idiscu;
		for (jdisc = 1; jdisc <= i__1; ++jdisc) {
		    iw = 0;
		    i__2 = *m;
		    for (je = 1; je <= i__2; ++je) {
			if (iblock[je] != 0 && (w[je] >= wkill || iw == 0)) {
			    iw = je;
			    wkill = w[je];
			}
/* L110: */
		    }
		    iblock[iw] = 0;
/* L120: */
		}
	    }
/*           Now erase all eigenvalues with IBLOCK set to zero */
	    im = 0;
	    i__1 = *m;
	    for (je = 1; je <= i__1; ++je) {
		if (iblock[je] != 0) {
		    ++im;
		    w[im] = w[je];
		    werr[im] = werr[je];
		    indexw[im] = indexw[je];
		    iblock[im] = iblock[je];
		}
/* L130: */
	    }
	    *m = im;
	}
	if (idiscl < 0 || idiscu < 0) {
	    toofew = TRUE_;
	}
    }

    if (irange == 1 && *m != *n || irange == 3 && *m != *iu - *il + 1) {
	toofew = TRUE_;
    }
/*     If ORDER='B', do nothing the eigenvalues are already sorted by   
          block.   
       If ORDER='E', sort the eigenvalues from smallest to largest */
    if (igraphlsame_(order, "E") && *nsplit > 1) {
	i__1 = *m - 1;
	for (je = 1; je <= i__1; ++je) {
	    ie = 0;
	    tmp1 = w[je];
	    i__2 = *m;
	    for (j = je + 1; j <= i__2; ++j) {
		if (w[j] < tmp1) {
		    ie = j;
		    tmp1 = w[j];
		}
/* L140: */
	    }
	    if (ie != 0) {
		tmp2 = werr[ie];
		itmp1 = iblock[ie];
		itmp2 = indexw[ie];
		w[ie] = w[je];
		werr[ie] = werr[je];
		iblock[ie] = iblock[je];
		indexw[ie] = indexw[je];
		w[je] = tmp1;
		werr[je] = tmp2;
		iblock[je] = itmp1;
		indexw[je] = itmp2;
	    }
/* L150: */
	}
    }

    *info = 0;
    if (ncnvrg) {
	++(*info);
    }
    if (toofew) {
	*info += 2;
    }
    return 0;

/*     End of DLARRD */

} /* igraphdlarrd_ */

