LAPACK
3.4.2
LAPACK: Linear Algebra PACKage

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Functions/Subroutines  
REAL function  slantp (NORM, UPLO, DIAG, N, AP, WORK) 
SLANTP returns the value of the 1norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a triangular matrix supplied in packed form. 
REAL function slantp  (  character  NORM, 
character  UPLO,  
character  DIAG,  
integer  N,  
real, dimension( * )  AP,  
real, dimension( * )  WORK  
) 
SLANTP returns the value of the 1norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a triangular matrix supplied in packed form.
Download SLANTP + dependencies [TGZ] [ZIP] [TXT]SLANTP 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.
SLANTP = ( 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.
[in]  NORM  NORM is CHARACTER*1 Specifies the value to be returned in SLANTP as described above. 
[in]  UPLO  UPLO is CHARACTER*1 Specifies whether the matrix A is upper or lower triangular. = 'U': Upper triangular = 'L': Lower triangular 
[in]  DIAG  DIAG is CHARACTER*1 Specifies whether or not the matrix A is unit triangular. = 'N': Nonunit triangular = 'U': Unit triangular 
[in]  N  N is INTEGER The order of the matrix A. N >= 0. When N = 0, SLANTP is set to zero. 
[in]  AP  AP is REAL array, dimension (N*(N+1)/2) The upper or lower triangular matrix A, packed columnwise in a linear array. The jth column of A is stored in the array AP as follows: if UPLO = 'U', AP(i + (j1)*j/2) = A(i,j) for 1<=i<=j; if UPLO = 'L', AP(i + (j1)*(2nj)/2) = A(i,j) for j<=i<=n. Note that when DIAG = 'U', the elements of the array AP corresponding to the diagonal elements of the matrix A are not referenced, but are assumed to be one. 
[out]  WORK  WORK is REAL array, dimension (MAX(1,LWORK)), where LWORK >= N when NORM = 'I'; otherwise, WORK is not referenced. 
Definition at line 125 of file slantp.f.