DOUBLE PRECISION function zlangt (NORM, N, DL, D, DU)
DOUBLE PRECISION function zlangt (characterNORM, integerN, complex*16, dimension( * )DL, complex*16, dimension( * )D, complex*16, dimension( * )DU)ZLANGT returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value of any element of a general tridiagonal matrix. Purpose:
ZLANGT returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a complex tridiagonal matrix A.
ZLANGT = ( max(abs(A(i,j))), NORM = 'M' or 'm' ( ( norm1(A), NORM = '1', 'O' or 'o' ( ( normI(A), NORM = 'I' or 'i' ( ( normF(A), NORM = 'F', 'f', 'E' 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(A(i,j))) is not a consistent matrix norm.
NORM is CHARACTER*1 Specifies the value to be returned in ZLANGT as described above.N
N is INTEGER The order of the matrix A. N >= 0. When N = 0, ZLANGT is set to zero.DL
DL is COMPLEX*16 array, dimension (N-1) The (n-1) sub-diagonal elements of A.D
D is COMPLEX*16 array, dimension (N) The diagonal elements of A.DU
DU is COMPLEX*16 array, dimension (N-1) The (n-1) super-diagonal elements of A.
Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd.Date:
September 2012Definition at line 107 of file zlangt.f.