Ztbcon Ztbtrs Ztpcon Ztptri Ztptrs Ztrcon Ztrtri Ztrtrs

Ztpcon() Sub Ztpcon ( Norm As  String, Uplo As  String, Diag As  String, N As  Long, Ap() As  Complex, RCond As  Double, Info As  Long  ) Condition number of a complex triangular matrix in packed form Purpose This routine estimates the reciprocal of the condition number of a packed triangular matrix A, in either the 1-norm or the infinity-norm. The norm of A is computed and an estimate is obtained for norm(inv(A)), then the reciprocal of the condition number is computed as RCond = 1 / (norm(A) * norm(inv(A))). Parameters [in] Norm Specifies whether the 1-norm condition number or the infinity-norm condition number is required: = "1" or "O": 1-norm. = "I": Infinity-norm. [in] Uplo = "U": A is upper triangular. = "L": A is lower triangular. [in] Diag = "N": A is non-unit triangular. = "U": A is unit triangular. (Diagonal elements of Ap() are not referenced and are assumed to be 1) [in] N Order of the matrix A. (N >= 0) (If N = 0, returns RCond = 1) [in] Ap() Array Ap(LAp - 1) (LAp >= N(N + 1)/2) N x N triangular matrix A in packed symmetric matrix form. Upper or lower part is to be stored in accordance with Uplo. [out] RCond The reciprocal of the condition number of the matrix A, computed as RCond = 1/(norm(A) * norm(inv(A))). [out] Info = 0: Successful exit. = -1: The argument Norm had an illegal value. (Norm <> "1", "O" nor "I") = -2: The argument Uplo had an illegal value. (Uplo <> "U" nor "L") = -3: The argument Diag had an illegal value. (Diag <> "N" nor "U") = -4: The argument N had an illegal value. (N < 0) = -5: The argument Ap() is invalid. Reference LAPACK Example Program See example of Ztptrs.