Zlangb Zlange Zlangt Zlanhb Zlanhe Zlanhp Zlanht Zlansb Zlansp Zlansy Zlantr

Zlangt() Function Zlangt ( Norm As  String, N As  Long, Dl() As  Complex, D() As  Complex, Du() As  Complex, Optional Info As  Long  ) One norm, Frobenius norm, infinity norm, or largest absolute value of any element of a complex tridiagonal matrix Purpose This routine returns the value of the one norm, the Frobenius norm, the infinity norm, or the largest absolute value of any element of a complex tridiagonal matrix A. Returns Double max(abs(Aij)) when Norm = "M", norm1(A) when Norm = "1" or "O", normI(A) when Norm = "I", or normF(A) when Norm = "F" or "E" where norm1 denotes the one norm of a matrix (maximum column sum), normI denotes the infinity norm of a matrix (maximum row sum) and normF denotes the Frobenius norm of a matrix (square root of sum of squares). Note that max(abs(Aij)) is not a consistent matrix norm. Parameters [in] Norm Specifies the value to be returned by Zlangt as described above. [in] N Order of the matrix A. (N >= 0) (If N = 0, returns 0) [in] Dl() Array Dl(LDl - 1) (LDl >= N - 1) Sub-diagonal elements of tridiagonal matrix A. [in] D() Array D(LD - 1) (LD >= N) Diagonal elements of tridiagonal matrix A. [in] Du() Array Du(LDu - 1) (LDu >= N - 1) Super-diagonal elements of tridiagonal matrix A. [out] Info (Optional) = 0: Successful exit. = -1: The argument Norm had an illegal value. (Norm <> "M", "1", "O", "I", "F" nor "E") = -2: The argument N had an illegal value. (N < 0) = -3: The argument Dl() is invalid. = -4: The argument D() is invalid. = -5: The argument Du() is invalid. Reference LAPACK