text: #include "f2c.h"
  #include "blaswrap.h"
  
  /* Subroutine */ int zppsv_(char *uplo, integer *n, integer *nrhs, 
  	doublecomplex *ap, doublecomplex *b, integer *ldb, integer *info)
  {
      /* System generated locals */
      integer b_dim1, b_offset, i__1;
  
      /* Local variables */
      extern logical lsame_(char *, char *);
      extern /* Subroutine */ int xerbla_(char *, integer *), zpptrf_(
  	    char *, integer *, doublecomplex *, integer *), zpptrs_(
  	    char *, integer *, integer *, doublecomplex *, doublecomplex *, 
  	    integer *, integer *);
  
  
  /*  -- LAPACK driver routine (version 3.1) -- */
  /*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
  /*     November 2006 */
  
  /*     .. Scalar Arguments .. */
  /*     .. */
  /*     .. Array Arguments .. */
  /*     .. */
  
  /*  Purpose */
  /*  ======= */
  
  /*  ZPPSV computes the solution to a complex system of linear equations */
  /*     A * X = B, */
  /*  where A is an N-by-N Hermitian positive definite matrix stored in */
  /*  packed format and X and B are N-by-NRHS matrices. */
  
  /*  The Cholesky decomposition is used to factor A as */
  /*     A = U**H* U,  if UPLO = 'U', or */
  /*     A = L * L**H,  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. */
  
  /*  AP      (input/output) COMPLEX*16 array, dimension (N*(N+1)/2) */
  /*          On entry, the upper or lower triangle of the Hermitian matrix */
  /*          A, packed columnwise in a linear array.  The j-th column of A */
  /*          is stored in the array AP as follows: */
  /*          if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; */
  /*          if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n. */
  /*          See below for further details. */
  
  /*          On exit, if INFO = 0, the factor U or L from the Cholesky */
  /*          factorization A = U**H*U or A = L*L**H, in the same storage */
  /*          format as A. */
  
  /*  B       (input/output) COMPLEX*16 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. */
  
  /*  Further Details */
  /*  =============== */
  
  /*  The packed storage scheme is illustrated by the following example */
  /*  when N = 4, UPLO = 'U': */
  
  /*  Two-dimensional storage of the Hermitian matrix A: */
  
  /*     a11 a12 a13 a14 */
  /*         a22 a23 a24 */
  /*             a33 a34     (aij = conjg(aji)) */
  /*                 a44 */
  
  /*  Packed storage of the upper triangle of A: */
  
  /*  AP = [ a11, a12, a22, a13, a23, a33, a14, a24, a34, a44 ] */
  
  /*  ===================================================================== */
  
  /*     .. External Functions .. */
  /*     .. */
  /*     .. External Subroutines .. */
  /*     .. */
  /*     .. Intrinsic Functions .. */
  /*     .. */
  /*     .. Executable Statements .. */
  
  /*     Test the input parameters. */
  
      /* Parameter adjustments */
      --ap;
      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 (*ldb < max(1,*n)) {
  	*info = -6;
      }
      if (*info != 0) {
  	i__1 = -(*info);
  	xerbla_("ZPPSV ", &i__1);
  	return 0;
      }
  
  /*     Compute the Cholesky factorization A = U'*U or A = L*L'. */
  
      zpptrf_(uplo, n, &ap[1], info);
      if (*info == 0) {
  
  /*        Solve the system A*X = B, overwriting B with X. */
  
  	zpptrs_(uplo, n, nrhs, &ap[1], &b[b_offset], ldb, info);
  
      }
      return 0;
  
  /*     End of ZPPSV */
  
  } /* zppsv_ */
  