#include "blaswrap.h"
/*  -- translated by f2c (version 19990503).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

/* Table of constant values */

static integer c__1 = 1;
static real c_b12 = 0.f;
static real c_b15 = 1.f;

/* Subroutine */ int sget52_(logical *left, integer *n, real *a, integer *lda,
	 real *b, integer *ldb, real *e, integer *lde, real *alphar, real *
	alphai, real *beta, real *work, real *result)
{
    /* System generated locals */
    integer a_dim1, a_offset, b_dim1, b_offset, e_dim1, e_offset, i__1, i__2;
    real r__1, r__2, r__3, r__4;

    /* Local variables */
    static integer jvec;
    static real temp1;
    static integer j;
    static real acoef, scale, abmax, salfi, sbeta, salfr, anorm, bnorm, enorm;
    extern /* Subroutine */ int sgemv_(char *, integer *, integer *, real *, 
	    real *, integer *, real *, integer *, real *, real *, integer *);
    static char trans[1];
    static real bcoefi, bcoefr, alfmax;
    extern doublereal slamch_(char *), slange_(char *, integer *, 
	    integer *, real *, integer *, real *);
    static real safmin;
    static char normab[1];
    static real safmax, betmax, enrmer;
    static logical ilcplx;
    static real errnrm, ulp;


#define e_ref(a_1,a_2) e[(a_2)*e_dim1 + a_1]


/*  -- LAPACK test routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       September 30, 1994   


    Purpose   
    =======   

    SGET52  does an eigenvector check for the generalized eigenvalue   
    problem.   

    The basic test for right eigenvectors is:   

                              | b(j) A E(j) -  a(j) B E(j) |   
            RESULT(1) = max   -------------------------------   
                         j    n ulp max( |b(j) A|, |a(j) B| )   

    using the 1-norm.  Here, a(j)/b(j) = w is the j-th generalized   
    eigenvalue of A - w B, or, equivalently, b(j)/a(j) = m is the j-th   
    generalized eigenvalue of m A - B.   

    For real eigenvalues, the test is straightforward.  For complex   
    eigenvalues, E(j) and a(j) are complex, represented by   
    Er(j) + i*Ei(j) and ar(j) + i*ai(j), resp., so the test for that   
    eigenvector becomes   

                    max( |Wr|, |Wi| )   
        --------------------------------------------   
        n ulp max( |b(j) A|, (|ar(j)|+|ai(j)|) |B| )   

    where   

        Wr = b(j) A Er(j) - ar(j) B Er(j) + ai(j) B Ei(j)   

        Wi = b(j) A Ei(j) - ai(j) B Er(j) - ar(j) B Ei(j)   

                            T   T  _   
    For left eigenvectors, A , B , a, and b  are used.   

    SGET52 also tests the normalization of E.  Each eigenvector is   
    supposed to be normalized so that the maximum "absolute value"   
    of its elements is 1, where in this case, "absolute value"   
    of a complex value x is  |Re(x)| + |Im(x)| ; let us call this   
    maximum "absolute value" norm of a vector v  M(v).   
    if a(j)=b(j)=0, then the eigenvector is set to be the jth coordinate   
    vector.  The normalization test is:   

            RESULT(2) =      max       | M(v(j)) - 1 | / ( n ulp )   
                       eigenvectors v(j)   

    Arguments   
    =========   

    LEFT    (input) LOGICAL   
            =.TRUE.:  The eigenvectors in the columns of E are assumed   
                      to be *left* eigenvectors.   
            =.FALSE.: The eigenvectors in the columns of E are assumed   
                      to be *right* eigenvectors.   

    N       (input) INTEGER   
            The size of the matrices.  If it is zero, SGET52 does   
            nothing.  It must be at least zero.   

    A       (input) REAL array, dimension (LDA, N)   
            The matrix A.   

    LDA     (input) INTEGER   
            The leading dimension of A.  It must be at least 1   
            and at least N.   

    B       (input) REAL array, dimension (LDB, N)   
            The matrix B.   

    LDB     (input) INTEGER   
            The leading dimension of B.  It must be at least 1   
            and at least N.   

    E       (input) REAL array, dimension (LDE, N)   
            The matrix of eigenvectors.  It must be O( 1 ).  Complex   
            eigenvalues and eigenvectors always come in pairs, the   
            eigenvalue and its conjugate being stored in adjacent   
            elements of ALPHAR, ALPHAI, and BETA.  Thus, if a(j)/b(j)   
            and a(j+1)/b(j+1) are a complex conjugate pair of   
            generalized eigenvalues, then E(,j) contains the real part   
            of the eigenvector and E(,j+1) contains the imaginary part.   
            Note that whether E(,j) is a real eigenvector or part of a   
            complex one is specified by whether ALPHAI(j) is zero or not.   

    LDE     (input) INTEGER   
            The leading dimension of E.  It must be at least 1 and at   
            least N.   

    ALPHAR  (input) REAL array, dimension (N)   
            The real parts of the values a(j) as described above, which,   
            along with b(j), define the generalized eigenvalues.   
            Complex eigenvalues always come in complex conjugate pairs   
            a(j)/b(j) and a(j+1)/b(j+1), which are stored in adjacent   
            elements in ALPHAR, ALPHAI, and BETA.  Thus, if the j-th   
            and (j+1)-st eigenvalues form a pair, ALPHAR(j+1)/BETA(j+1)   
            is assumed to be equal to ALPHAR(j)/BETA(j).   

    ALPHAI  (input) REAL array, dimension (N)   
            The imaginary parts of the values a(j) as described above,   
            which, along with b(j), define the generalized eigenvalues.   
            If ALPHAI(j)=0, then the eigenvalue is real, otherwise it   
            is part of a complex conjugate pair.  Complex eigenvalues   
            always come in complex conjugate pairs a(j)/b(j) and   
            a(j+1)/b(j+1), which are stored in adjacent elements in   
            ALPHAR, ALPHAI, and BETA.  Thus, if the j-th and (j+1)-st   
            eigenvalues form a pair, ALPHAI(j+1)/BETA(j+1) is assumed to   
            be equal to  -ALPHAI(j)/BETA(j).  Also, nonzero values in   
            ALPHAI are assumed to always come in adjacent pairs.   

    BETA    (input) REAL array, dimension (N)   
            The values b(j) as described above, which, along with a(j),   
            define the generalized eigenvalues.   

    WORK    (workspace) REAL array, dimension (N**2+N)   

    RESULT  (output) REAL array, dimension (2)   
            The values computed by the test described above.  If A E or   
            B E is likely to overflow, then RESULT(1:2) is set to   
            10 / ulp.   

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


       Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1 * 1;
    b -= b_offset;
    e_dim1 = *lde;
    e_offset = 1 + e_dim1 * 1;
    e -= e_offset;
    --alphar;
    --alphai;
    --beta;
    --work;
    --result;

    /* Function Body */
    result[1] = 0.f;
    result[2] = 0.f;
    if (*n <= 0) {
	return 0;
    }

    safmin = slamch_("Safe minimum");
    safmax = 1.f / safmin;
    ulp = slamch_("Epsilon") * slamch_("Base");

    if (*left) {
	*(unsigned char *)trans = 'T';
	*(unsigned char *)normab = 'I';
    } else {
	*(unsigned char *)trans = 'N';
	*(unsigned char *)normab = 'O';
    }

/*     Norm of A, B, and E:   

   Computing MAX */
    r__1 = slange_(normab, n, n, &a[a_offset], lda, &work[1]);
    anorm = dmax(r__1,safmin);
/* Computing MAX */
    r__1 = slange_(normab, n, n, &b[b_offset], ldb, &work[1]);
    bnorm = dmax(r__1,safmin);
/* Computing MAX */
    r__1 = slange_("O", n, n, &e[e_offset], lde, &work[1]);
    enorm = dmax(r__1,ulp);
    alfmax = safmax / dmax(1.f,bnorm);
    betmax = safmax / dmax(1.f,anorm);

/*     Compute error matrix.   
       Column i = ( b(i) A - a(i) B ) E(i) / max( |a(i) B| |b(i) A| ) */

    ilcplx = FALSE_;
    i__1 = *n;
    for (jvec = 1; jvec <= i__1; ++jvec) {
	if (ilcplx) {

/*           2nd Eigenvalue/-vector of pair -- do nothing */

	    ilcplx = FALSE_;
	} else {
	    salfr = alphar[jvec];
	    salfi = alphai[jvec];
	    sbeta = beta[jvec];
	    if (salfi == 0.f) {

/*              Real eigenvalue and -vector   

   Computing MAX */
		r__1 = dabs(salfr), r__2 = dabs(sbeta);
		abmax = dmax(r__1,r__2);
		if (dabs(salfr) > alfmax || dabs(sbeta) > betmax || abmax < 
			1.f) {
		    scale = 1.f / dmax(abmax,safmin);
		    salfr = scale * salfr;
		    sbeta = scale * sbeta;
		}
/* Computing MAX */
		r__1 = dabs(salfr) * bnorm, r__2 = dabs(sbeta) * anorm, r__1 =
			 max(r__1,r__2);
		scale = 1.f / dmax(r__1,safmin);
		acoef = scale * sbeta;
		bcoefr = scale * salfr;
		sgemv_(trans, n, n, &acoef, &a[a_offset], lda, &e_ref(1, jvec)
			, &c__1, &c_b12, &work[*n * (jvec - 1) + 1], &c__1);
		r__1 = -bcoefr;
		sgemv_(trans, n, n, &r__1, &b[b_offset], lda, &e_ref(1, jvec),
			 &c__1, &c_b15, &work[*n * (jvec - 1) + 1], &c__1);
	    } else {

/*              Complex conjugate pair */

		ilcplx = TRUE_;
		if (jvec == *n) {
		    result[1] = 10.f / ulp;
		    return 0;
		}
/* Computing MAX */
		r__1 = dabs(salfr) + dabs(salfi), r__2 = dabs(sbeta);
		abmax = dmax(r__1,r__2);
		if (dabs(salfr) + dabs(salfi) > alfmax || dabs(sbeta) > 
			betmax || abmax < 1.f) {
		    scale = 1.f / dmax(abmax,safmin);
		    salfr = scale * salfr;
		    salfi = scale * salfi;
		    sbeta = scale * sbeta;
		}
/* Computing MAX */
		r__1 = (dabs(salfr) + dabs(salfi)) * bnorm, r__2 = dabs(sbeta)
			 * anorm, r__1 = max(r__1,r__2);
		scale = 1.f / dmax(r__1,safmin);
		acoef = scale * sbeta;
		bcoefr = scale * salfr;
		bcoefi = scale * salfi;
		if (*left) {
		    bcoefi = -bcoefi;
		}

		sgemv_(trans, n, n, &acoef, &a[a_offset], lda, &e_ref(1, jvec)
			, &c__1, &c_b12, &work[*n * (jvec - 1) + 1], &c__1);
		r__1 = -bcoefr;
		sgemv_(trans, n, n, &r__1, &b[b_offset], lda, &e_ref(1, jvec),
			 &c__1, &c_b15, &work[*n * (jvec - 1) + 1], &c__1);
		sgemv_(trans, n, n, &bcoefi, &b[b_offset], lda, &e_ref(1, 
			jvec + 1), &c__1, &c_b15, &work[*n * (jvec - 1) + 1], 
			&c__1);

		sgemv_(trans, n, n, &acoef, &a[a_offset], lda, &e_ref(1, jvec 
			+ 1), &c__1, &c_b12, &work[*n * jvec + 1], &c__1);
		r__1 = -bcoefi;
		sgemv_(trans, n, n, &r__1, &b[b_offset], lda, &e_ref(1, jvec),
			 &c__1, &c_b15, &work[*n * jvec + 1], &c__1);
		r__1 = -bcoefr;
		sgemv_(trans, n, n, &r__1, &b[b_offset], lda, &e_ref(1, jvec 
			+ 1), &c__1, &c_b15, &work[*n * jvec + 1], &c__1);
	    }
	}
/* L10: */
    }

/* Computing 2nd power */
    i__1 = *n;
    errnrm = slange_("One", n, n, &work[1], n, &work[i__1 * i__1 + 1]) / enorm;

/*     Compute RESULT(1) */

    result[1] = errnrm / ulp;

/*     Normalization of E: */

    enrmer = 0.f;
    ilcplx = FALSE_;
    i__1 = *n;
    for (jvec = 1; jvec <= i__1; ++jvec) {
	if (ilcplx) {
	    ilcplx = FALSE_;
	} else {
	    temp1 = 0.f;
	    if (alphai[jvec] == 0.f) {
		i__2 = *n;
		for (j = 1; j <= i__2; ++j) {
/* Computing MAX */
		    r__2 = temp1, r__3 = (r__1 = e_ref(j, jvec), dabs(r__1));
		    temp1 = dmax(r__2,r__3);
/* L20: */
		}
/* Computing MAX */
		r__1 = enrmer, r__2 = temp1 - 1.f;
		enrmer = dmax(r__1,r__2);
	    } else {
		ilcplx = TRUE_;
		i__2 = *n;
		for (j = 1; j <= i__2; ++j) {
/* Computing MAX */
		    r__3 = temp1, r__4 = (r__1 = e_ref(j, jvec), dabs(r__1)) 
			    + (r__2 = e_ref(j, jvec + 1), dabs(r__2));
		    temp1 = dmax(r__3,r__4);
/* L30: */
		}
/* Computing MAX */
		r__1 = enrmer, r__2 = temp1 - 1.f;
		enrmer = dmax(r__1,r__2);
	    }
	}
/* L40: */
    }

/*     Compute RESULT(2) : the normalization error in E. */

    result[2] = enrmer / ((real) (*n) * ulp);

    return 0;

/*     End of SGET52 */

} /* sget52_ */

#undef e_ref


