#include "blaswrap.h"
/* sget51.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"

/* Table of constant values */

static real c_b9 = 1.f;
static real c_b10 = 0.f;
static real c_b13 = -1.f;

/* Subroutine */ int sget51_(integer *itype, integer *n, real *a, integer *
	lda, real *b, integer *ldb, real *u, integer *ldu, real *v, integer *
	ldv, real *work, real *result)
{
    /* System generated locals */
    integer a_dim1, a_offset, b_dim1, b_offset, u_dim1, u_offset, v_dim1, 
	    v_offset, i__1, i__2;
    real r__1, r__2;

    /* Local variables */
    static real ulp;
    static integer jcol;
    static real unfl;
    static integer jrow, jdiag;
    extern /* Subroutine */ int sgemm_(char *, char *, integer *, integer *, 
	    integer *, real *, real *, integer *, real *, integer *, real *, 
	    real *, integer *);
    static real anorm, wnorm;
    extern doublereal slamch_(char *), slange_(char *, integer *, 
	    integer *, real *, integer *, real *);
    extern /* Subroutine */ int slacpy_(char *, integer *, integer *, real *, 
	    integer *, real *, integer *);


/*  -- LAPACK test routine (version 3.1) --   
       Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..   
       November 2006   


    Purpose   
    =======   

         SGET51  generally checks a decomposition of the form   

                 A = U B V'   

         where ' means transpose and U and V are orthogonal.   

         Specifically, if ITYPE=1   

                 RESULT = | A - U B V' | / ( |A| n ulp )   

         If ITYPE=2, then:   

                 RESULT = | A - B | / ( |A| n ulp )   

         If ITYPE=3, then:   

                 RESULT = | I - UU' | / ( n ulp )   

    Arguments   
    =========   

    ITYPE   (input) INTEGER   
            Specifies the type of tests to be performed.   
            =1: RESULT = | A - U B V' | / ( |A| n ulp )   
            =2: RESULT = | A - B | / ( |A| n ulp )   
            =3: RESULT = | I - UU' | / ( n ulp )   

    N       (input) INTEGER   
            The size of the matrix.  If it is zero, SGET51 does nothing.   
            It must be at least zero.   

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

    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 factored matrix.   

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

    U       (input) REAL array, dimension (LDU, N)   
            The orthogonal matrix on the left-hand side in the   
            decomposition.   
            Not referenced if ITYPE=2   

    LDU     (input) INTEGER   
            The leading dimension of U.  LDU must be at least N and   
            at least 1.   

    V       (input) REAL array, dimension (LDV, N)   
            The orthogonal matrix on the left-hand side in the   
            decomposition.   
            Not referenced if ITYPE=2   

    LDV     (input) INTEGER   
            The leading dimension of V.  LDV must be at least N and   
            at least 1.   

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

    RESULT  (output) REAL   
            The values computed by the test specified by ITYPE.  The   
            value is currently limited to 1/ulp, to avoid overflow.   
            Errors are flagged by RESULT=10/ulp.   

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


       Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1;
    b -= b_offset;
    u_dim1 = *ldu;
    u_offset = 1 + u_dim1;
    u -= u_offset;
    v_dim1 = *ldv;
    v_offset = 1 + v_dim1;
    v -= v_offset;
    --work;

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

/*     Constants */

    unfl = slamch_("Safe minimum");
    ulp = slamch_("Epsilon") * slamch_("Base");

/*     Some Error Checks */

    if (*itype < 1 || *itype > 3) {
	*result = 10.f / ulp;
	return 0;
    }

    if (*itype <= 2) {

/*        Tests scaled by the norm(A)   

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

	if (*itype == 1) {

/*           ITYPE=1: Compute W = A - UBV' */

	    slacpy_(" ", n, n, &a[a_offset], lda, &work[1], n);
/* Computing 2nd power */
	    i__1 = *n;
	    sgemm_("N", "N", n, n, n, &c_b9, &u[u_offset], ldu, &b[b_offset], 
		    ldb, &c_b10, &work[i__1 * i__1 + 1], n);

/* Computing 2nd power */
	    i__1 = *n;
	    sgemm_("N", "C", n, n, n, &c_b13, &work[i__1 * i__1 + 1], n, &v[
		    v_offset], ldv, &c_b9, &work[1], n);

	} else {

/*           ITYPE=2: Compute W = A - B */

	    slacpy_(" ", n, n, &b[b_offset], ldb, &work[1], n);

	    i__1 = *n;
	    for (jcol = 1; jcol <= i__1; ++jcol) {
		i__2 = *n;
		for (jrow = 1; jrow <= i__2; ++jrow) {
		    work[jrow + *n * (jcol - 1)] -= a[jrow + jcol * a_dim1];
/* L10: */
		}
/* L20: */
	    }
	}

/*        Compute norm(W)/ ( ulp*norm(A) )   

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

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

    } else {

/*        Tests not scaled by norm(A)   

          ITYPE=3: Compute  UU' - I */

	sgemm_("N", "C", n, n, n, &c_b9, &u[u_offset], ldu, &u[u_offset], ldu, 
		 &c_b10, &work[1], n);

	i__1 = *n;
	for (jdiag = 1; jdiag <= i__1; ++jdiag) {
	    work[(*n + 1) * (jdiag - 1) + 1] += -1.f;
/* L30: */
	}

/* Computing MIN   
   Computing 2nd power */
	i__1 = *n;
	r__1 = slange_("1", n, n, &work[1], n, &work[i__1 * i__1 + 1]), r__2 = (real) (*n);
	*result = dmin(r__1,r__2) / (*n * ulp);
    }

    return 0;

/*     End of SGET51 */

} /* sget51_ */