text: /* dposv.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"
  #include "blaswrap.h"
  
  /* Subroutine */ int dposv_(char *uplo, integer *n, integer *nrhs, doublereal 
  	*a, integer *lda, doublereal *b, integer *ldb, integer *info)
  {
      /* System generated locals */
      integer a_dim1, a_offset, b_dim1, b_offset, i__1;
  
      /* Local variables */
      extern logical lsame_(char *, char *);
      extern /* Subroutine */ int xerbla_(char *, integer *), dpotrf_(
  	    char *, integer *, doublereal *, integer *, integer *), 
  	    dpotrs_(char *, integer *, integer *, doublereal *, integer *, 
  	    doublereal *, integer *, integer *);
  
  
  /*  -- LAPACK driver routine (version 3.2) -- */
  /*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
  /*     November 2006 */
  
  /*     .. Scalar Arguments .. */
  /*     .. */
  /*     .. Array Arguments .. */
  /*     .. */
  
  /*  Purpose */
  /*  ======= */
  
  /*  DPOSV computes the solution to a real system of linear equations */
  /*     A * X = B, */
  /*  where A is an N-by-N symmetric positive definite matrix and X and B */
  /*  are N-by-NRHS matrices. */
  
  /*  The Cholesky decomposition is used to factor A as */
  /*     A = U**T* U,  if UPLO = 'U', or */
  /*     A = L * L**T,  if UPLO = 'L', */
  /*  where U is an upper triangular matrix and L is a lower triangular */
  /*  matrix.  The factored form of A is then used to solve the system of */
  /*  equations A * X = B. */
  
  /*  Arguments */
  /*  ========= */
  
  /*  UPLO    (input) CHARACTER*1 */
  /*          = 'U':  Upper triangle of A is stored; */
  /*          = 'L':  Lower triangle of A is stored. */
  
  /*  N       (input) INTEGER */
  /*          The number of linear equations, i.e., the order of the */
  /*          matrix A.  N >= 0. */
  
  /*  NRHS    (input) INTEGER */
  /*          The number of right hand sides, i.e., the number of columns */
  /*          of the matrix B.  NRHS >= 0. */
  
  /*  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N) */
  /*          On entry, the symmetric matrix A.  If UPLO = 'U', the leading */
  /*          N-by-N upper triangular part of A contains the upper */
  /*          triangular part of the matrix A, and the strictly lower */
  /*          triangular part of A is not referenced.  If UPLO = 'L', the */
  /*          leading N-by-N lower triangular part of A contains the lower */
  /*          triangular part of the matrix A, and the strictly upper */
  /*          triangular part of A is not referenced. */
  
  /*          On exit, if INFO = 0, the factor U or L from the Cholesky */
  /*          factorization A = U**T*U or A = L*L**T. */
  
  /*  LDA     (input) INTEGER */
  /*          The leading dimension of the array A.  LDA >= max(1,N). */
  
  /*  B       (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS) */
  /*          On entry, the N-by-NRHS right hand side matrix B. */
  /*          On exit, if INFO = 0, the N-by-NRHS solution matrix X. */
  
  /*  LDB     (input) INTEGER */
  /*          The leading dimension of the array B.  LDB >= max(1,N). */
  
  /*  INFO    (output) INTEGER */
  /*          = 0:  successful exit */
  /*          < 0:  if INFO = -i, the i-th argument had an illegal value */
  /*          > 0:  if INFO = i, the leading minor of order i of A is not */
  /*                positive definite, so the factorization could not be */
  /*                completed, and the solution has not been computed. */
  
  /*  ===================================================================== */
  
  /*     .. External Functions .. */
  /*     .. */
  /*     .. External Subroutines .. */
  /*     .. */
  /*     .. Intrinsic Functions .. */
  /*     .. */
  /*     .. Executable Statements .. */
  
  /*     Test the input parameters. */
  
      /* Parameter adjustments */
      a_dim1 = *lda;
      a_offset = 1 + a_dim1;
      a -= a_offset;
      b_dim1 = *ldb;
      b_offset = 1 + b_dim1;
      b -= b_offset;
  
      /* Function Body */
      *info = 0;
      if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) {
  	*info = -1;
      } else if (*n < 0) {
  	*info = -2;
      } else if (*nrhs < 0) {
  	*info = -3;
      } else if (*lda < max(1,*n)) {
  	*info = -5;
      } else if (*ldb < max(1,*n)) {
  	*info = -7;
      }
      if (*info != 0) {
  	i__1 = -(*info);
  	xerbla_("DPOSV ", &i__1);
  	return 0;
      }
  
  /*     Compute the Cholesky factorization A = U'*U or A = L*L'. */
  
      dpotrf_(uplo, n, &a[a_offset], lda, info);
      if (*info == 0) {
  
  /*        Solve the system A*X = B, overwriting B with X. */
  
  	dpotrs_(uplo, n, nrhs, &a[a_offset], lda, &b[b_offset], ldb, info);
  
      }
      return 0;
  
  /*     End of DPOSV */
  
  } /* dposv_ */
  