#include "blaswrap.h"
/* dspt01.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 doublereal c_b5 = 0.;
static doublereal c_b6 = 1.;

/* Subroutine */ int dspt01_(char *uplo, integer *n, doublereal *a, 
	doublereal *afac, integer *ipiv, doublereal *c__, integer *ldc, 
	doublereal *rwork, doublereal *resid)
{
    /* System generated locals */
    integer c_dim1, c_offset, i__1, i__2;

    /* Local variables */
    static integer i__, j, jc;
    static doublereal eps;
    static integer info;
    extern logical lsame_(char *, char *);
    static doublereal anorm;
    extern doublereal dlamch_(char *);
    extern /* Subroutine */ int dlaset_(char *, integer *, integer *, 
	    doublereal *, doublereal *, doublereal *, integer *);
    extern doublereal dlansp_(char *, char *, integer *, doublereal *, 
	    doublereal *);
    extern /* Subroutine */ int dlavsp_(char *, char *, char *, integer *, 
	    integer *, doublereal *, integer *, doublereal *, integer *, 
	    integer *);
    extern doublereal dlansy_(char *, char *, integer *, doublereal *, 
	    integer *, doublereal *);


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


    Purpose   
    =======   

    DSPT01 reconstructs a symmetric indefinite packed matrix A from its   
    block L*D*L' or U*D*U' factorization and computes the residual   
         norm( C - A ) / ( N * norm(A) * EPS ),   
    where C is the reconstructed matrix and EPS is the machine epsilon.   

    Arguments   
    ==========   

    UPLO    (input) CHARACTER*1   
            Specifies whether the upper or lower triangular part of the   
            symmetric matrix A is stored:   
            = 'U':  Upper triangular   
            = 'L':  Lower triangular   

    N       (input) INTEGER   
            The number of rows and columns of the matrix A.  N >= 0.   

    A       (input) DOUBLE PRECISION array, dimension (N*(N+1)/2)   
            The original symmetric matrix A, stored as a packed   
            triangular matrix.   

    AFAC    (input) DOUBLE PRECISION array, dimension (N*(N+1)/2)   
            The factored form of the matrix A, stored as a packed   
            triangular matrix.  AFAC contains the block diagonal matrix D   
            and the multipliers used to obtain the factor L or U from the   
            block L*D*L' or U*D*U' factorization as computed by DSPTRF.   

    IPIV    (input) INTEGER array, dimension (N)   
            The pivot indices from DSPTRF.   

    C       (workspace) DOUBLE PRECISION array, dimension (LDC,N)   

    LDC     (integer) INTEGER   
            The leading dimension of the array C.  LDC >= max(1,N).   

    RWORK   (workspace) DOUBLE PRECISION array, dimension (N)   

    RESID   (output) DOUBLE PRECISION   
            If UPLO = 'L', norm(L*D*L' - A) / ( N * norm(A) * EPS )   
            If UPLO = 'U', norm(U*D*U' - A) / ( N * norm(A) * EPS )   

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


       Quick exit if N = 0.   

       Parameter adjustments */
    --a;
    --afac;
    --ipiv;
    c_dim1 = *ldc;
    c_offset = 1 + c_dim1;
    c__ -= c_offset;
    --rwork;

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

/*     Determine EPS and the norm of A. */

    eps = dlamch_("Epsilon");
    anorm = dlansp_("1", uplo, n, &a[1], &rwork[1]);

/*     Initialize C to the identity matrix. */

    dlaset_("Full", n, n, &c_b5, &c_b6, &c__[c_offset], ldc);

/*     Call DLAVSP to form the product D * U' (or D * L' ). */

    dlavsp_(uplo, "Transpose", "Non-unit", n, n, &afac[1], &ipiv[1], &c__[
	    c_offset], ldc, &info);

/*     Call DLAVSP again to multiply by U ( or L ). */

    dlavsp_(uplo, "No transpose", "Unit", n, n, &afac[1], &ipiv[1], &c__[
	    c_offset], ldc, &info);

/*     Compute the difference  C - A . */

    if (lsame_(uplo, "U")) {
	jc = 0;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    i__2 = j;
	    for (i__ = 1; i__ <= i__2; ++i__) {
		c__[i__ + j * c_dim1] -= a[jc + i__];
/* L10: */
	    }
	    jc += j;
/* L20: */
	}
    } else {
	jc = 1;
	i__1 = *n;
	for (j = 1; j <= i__1; ++j) {
	    i__2 = *n;
	    for (i__ = j; i__ <= i__2; ++i__) {
		c__[i__ + j * c_dim1] -= a[jc + i__ - j];
/* L30: */
	    }
	    jc = jc + *n - j + 1;
/* L40: */
	}
    }

/*     Compute norm( C - A ) / ( N * norm(A) * EPS ) */

    *resid = dlansy_("1", uplo, n, &c__[c_offset], ldc, &rwork[1]);

    if (anorm <= 0.) {
	if (*resid != 0.) {
	    *resid = 1. / eps;
	}
    } else {
	*resid = *resid / (doublereal) (*n) / anorm / eps;
    }

    return 0;

/*     End of DSPT01 */

} /* dspt01_ */