#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 real c_b6 = 1.f;
static real c_b7 = 0.f;

/* Subroutine */ int ssyt22_(integer *itype, char *uplo, integer *n, integer *
	m, integer *kband, real *a, integer *lda, real *d__, real *e, real *u,
	 integer *ldu, real *v, integer *ldv, real *tau, real *work, real *
	result)
{
    /* System generated locals */
    integer a_dim1, a_offset, u_dim1, u_offset, v_dim1, v_offset, i__1;
    real r__1, r__2;

    /* Local variables */
    static real unfl;
    static integer j;
    extern /* Subroutine */ int sgemm_(char *, char *, integer *, integer *, 
	    integer *, real *, real *, integer *, real *, integer *, real *, 
	    real *, integer *);
    static real anorm;
    extern /* Subroutine */ int sort01_(char *, integer *, integer *, real *, 
	    integer *, real *, integer *, real *);
    static real wnorm;
    extern /* Subroutine */ int ssymm_(char *, char *, integer *, integer *, 
	    real *, real *, integer *, real *, integer *, real *, real *, 
	    integer *);
    static integer jj, nn;
    extern doublereal slamch_(char *);
    static integer jj1, jj2;
    extern doublereal slansy_(char *, char *, integer *, real *, integer *, 
	    real *);
    static real ulp;
    static integer nnp1;


/*  -- LAPACK test routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       February 29, 1992   


    Purpose   
    =======   

         SSYT22  generally checks a decomposition of the form   

                 A U = U S   

         where A is symmetric, the columns of U are orthonormal, and S   
         is diagonal (if KBAND=0) or symmetric tridiagonal (if   
         KBAND=1).  If ITYPE=1, then U is represented as a dense matrix,   
         otherwise the U is expressed as a product of Householder   
         transformations, whose vectors are stored in the array "V" and   
         whose scaling constants are in "TAU"; we shall use the letter   
         "V" to refer to the product of Householder transformations   
         (which should be equal to U).   

         Specifically, if ITYPE=1, then:   

                 RESULT(1) = | U' A U - S | / ( |A| m ulp ) *and*   
                 RESULT(2) = | I - U'U | / ( m ulp )   

    Arguments   
    =========   

    ITYPE   INTEGER   
            Specifies the type of tests to be performed.   
            1: U expressed as a dense orthogonal matrix:   
               RESULT(1) = | A - U S U' | / ( |A| n ulp )   *and*   
               RESULT(2) = | I - UU' | / ( n ulp )   

    UPLO    CHARACTER   
            If UPLO='U', the upper triangle of A will be used and the   
            (strictly) lower triangle will not be referenced.  If   
            UPLO='L', the lower triangle of A will be used and the   
            (strictly) upper triangle will not be referenced.   
            Not modified.   

    N       INTEGER   
            The size of the matrix.  If it is zero, SSYT22 does nothing.   
            It must be at least zero.   
            Not modified.   

    M       INTEGER   
            The number of columns of U.  If it is zero, SSYT22 does   
            nothing.  It must be at least zero.   
            Not modified.   

    KBAND   INTEGER   
            The bandwidth of the matrix.  It may only be zero or one.   
            If zero, then S is diagonal, and E is not referenced.  If   
            one, then S is symmetric tri-diagonal.   
            Not modified.   

    A       REAL array, dimension (LDA , N)   
            The original (unfactored) matrix.  It is assumed to be   
            symmetric, and only the upper (UPLO='U') or only the lower   
            (UPLO='L') will be referenced.   
            Not modified.   

    LDA     INTEGER   
            The leading dimension of A.  It must be at least 1   
            and at least N.   
            Not modified.   

    D       REAL array, dimension (N)   
            The diagonal of the (symmetric tri-) diagonal matrix.   
            Not modified.   

    E       REAL array, dimension (N)   
            The off-diagonal of the (symmetric tri-) diagonal matrix.   
            E(1) is ignored, E(2) is the (1,2) and (2,1) element, etc.   
            Not referenced if KBAND=0.   
            Not modified.   

    U       REAL array, dimension (LDU, N)   
            If ITYPE=1 or 3, this contains the orthogonal matrix in   
            the decomposition, expressed as a dense matrix.  If ITYPE=2,   
            then it is not referenced.   
            Not modified.   

    LDU     INTEGER   
            The leading dimension of U.  LDU must be at least N and   
            at least 1.   
            Not modified.   

    V       REAL array, dimension (LDV, N)   
            If ITYPE=2 or 3, the lower triangle of this array contains   
            the Householder vectors used to describe the orthogonal   
            matrix in the decomposition.  If ITYPE=1, then it is not   
            referenced.   
            Not modified.   

    LDV     INTEGER   
            The leading dimension of V.  LDV must be at least N and   
            at least 1.   
            Not modified.   

    TAU     REAL array, dimension (N)   
            If ITYPE >= 2, then TAU(j) is the scalar factor of   
            v(j) v(j)' in the Householder transformation H(j) of   
            the product  U = H(1)...H(n-2)   
            If ITYPE < 2, then TAU is not referenced.   
            Not modified.   

    WORK    REAL array, dimension (2*N**2)   
            Workspace.   
            Modified.   

    RESULT  REAL array, dimension (2)   
            The values computed by the two tests described above.  The   
            values are currently limited to 1/ulp, to avoid overflow.   
            RESULT(1) is always modified.  RESULT(2) is modified only   
            if LDU is at least N.   
            Modified.   

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


       Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    --d__;
    --e;
    u_dim1 = *ldu;
    u_offset = 1 + u_dim1 * 1;
    u -= u_offset;
    v_dim1 = *ldv;
    v_offset = 1 + v_dim1 * 1;
    v -= v_offset;
    --tau;
    --work;
    --result;

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

    unfl = slamch_("Safe minimum");
    ulp = slamch_("Precision");

/*     Do Test 1   

       Norm of A:   

   Computing MAX */
    r__1 = slansy_("1", uplo, n, &a[a_offset], lda, &work[1]);
    anorm = dmax(r__1,unfl);

/*     Compute error matrix:   

       ITYPE=1: error = U' A U - S */

    ssymm_("L", uplo, n, m, &c_b6, &a[a_offset], lda, &u[u_offset], ldu, &
	    c_b7, &work[1], n);
    nn = *n * *n;
    nnp1 = nn + 1;
    sgemm_("T", "N", m, m, n, &c_b6, &u[u_offset], ldu, &work[1], n, &c_b7, &
	    work[nnp1], n);
    i__1 = *m;
    for (j = 1; j <= i__1; ++j) {
	jj = nn + (j - 1) * *n + j;
	work[jj] -= d__[j];
/* L10: */
    }
    if (*kband == 1 && *n > 1) {
	i__1 = *m;
	for (j = 2; j <= i__1; ++j) {
	    jj1 = nn + (j - 1) * *n + j - 1;
	    jj2 = nn + (j - 2) * *n + j;
	    work[jj1] -= e[j - 1];
	    work[jj2] -= e[j - 1];
/* L20: */
	}
    }
    wnorm = slansy_("1", uplo, m, &work[nnp1], n, &work[1]);

    if (anorm > wnorm) {
	result[1] = wnorm / anorm / (*m * ulp);
    } else {
	if (anorm < 1.f) {
/* Computing MIN */
	    r__1 = wnorm, r__2 = *m * anorm;
	    result[1] = dmin(r__1,r__2) / anorm / (*m * ulp);
	} else {
/* Computing MIN */
	    r__1 = wnorm / anorm, r__2 = (real) (*m);
	    result[1] = dmin(r__1,r__2) / (*m * ulp);
	}
    }

/*     Do Test 2   

       Compute  U'U - I */

    if (*itype == 1) {
	i__1 = (*n << 1) * *n;
	sort01_("Columns", n, m, &u[u_offset], ldu, &work[1], &i__1, &result[
		2]);
    }

    return 0;

/*     End of SSYT22 */

} /* ssyt22_ */

