ZLANTP - return the value of the one norm, or the Frobe
nius norm, or the infinity norm, or the element of largest
absolute value of a triangular matrix A, supplied in
packed form
SYNOPSIS
DOUBLE PRECISION FUNCTION ZLANTP( NORM, UPLO, DIAG, N, AP,
WORK )
CHARACTER DIAG, NORM, UPLO
INTEGER N
DOUBLE PRECISION WORK( * )
COMPLEX*16 AP( * )
PURPOSE
ZLANTP returns the value of the one norm, or the Frobenius
norm, or the infinity norm, or the element of largest
absolute value of a triangular matrix A, supplied in
packed form.
DESCRIPTION
ZLANTP returns the value
ZLANTP = ( 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 Frobe
nius norm of a matrix (square root of sum of squares).
Note that max(abs(A(i,j))) is not a matrix norm.
ARGUMENTS
NORM (input) CHARACTER*1
Specifies the value to be returned in ZLANTP as
described above.
UPLO (input) CHARACTER*1
Specifies whether the matrix A is upper or lower
triangular. = 'U': Upper triangular
= 'L': Lower triangular
Specifies whether or not the matrix A is unit tri
angular. = 'N': Non-unit triangular
= 'U': Unit triangular
N (input) INTEGER
The order of the matrix A. N >= 0. When N = 0,
ZLANTP is set to zero.
AP (input) COMPLEX*16 array, dimension (N*(N+1)/2)
The upper or lower triangular 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. Note that when DIAG = 'U', the elements
of the array AP corresponding to the diagonal ele
ments of the matrix A are not referenced, but are
assumed to be one.
WORK (workspace) DOUBLE PRECISION array, dimension
(LWORK),
where LWORK >= N when NORM = 'I'; otherwise, WORK
is not referenced.
Man(1) output converted with
man2html