zgbcon zgbtrf zgbtrs zgecon zgetrf zgetri zgetrs zgtcon zgttrf zgttrs zspcon zsptrf zsptri zsptrs zsycon zsytrf zsytri zsytrs

zspcon() void zspcon ( char  uplo, int  n, doublecomplex  ap[], int  ipiv[], double  anorm, double *  rcond, doublecomplex  work[], int *  info  ) Condition number of a complex symmetric matrix in packed form Purpose This routine estimates the reciprocal of the condition number (in the 1-norm) of a complex symmetric packed matrix A using the factorization A = U*D*U^T or A = L*D*L^T computed by zsptrf. An estimate is obtained for norm(inv(A)), and the reciprocal of the condition number is computed as rcond = 1 / (anorm * norm(inv(A))) Parameters [in] uplo Specifies whether the details of the factorization are stored as an upper or lower triangular matrix. = 'U': Upper triangular, form is A = U*D*U^T. = 'L': Lower triangular, form is A = L*D*L^T. [in] n Order of the matrix A. (n >= 0) (If n = 0, returns rcond = 1) [in] ap[] Array ap[lap] (lap >= n(n + 1)/2) The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by zsptrf, stored as a packed triangular matrix. [in] ipiv[] Array ipiv[lipiv] (lipiv >= n) Details of the interchanges and the block structure of D as determined by zsptrf. [in] anorm The 1-norm of the original matrix A. (anorm >= 0) [out] rcond The reciprocal of the condition number of the matrix A, computed as rcond = 1/(anorm * ainvnm), where ainvnm is an estimate of the 1-norm of inv(A) computed in this routine. [out] work[] Array work[lwork] (lwork >= 2*n) Work array. [out] info = 0: Successful exit = -1: The argument uplo had an illegal value (uplo != 'U' nor 'L') = -2: The argument n had an illegal value (n < 0) = -5: The argument anorm had an illegal value (anorm < 0) Reference LAPACK