Provided by: liblapack-doc_3.3.1-1_all

#### NAME

```       LAPACK-3 - 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

```

#### SYNOPSIS

```       REAL FUNCTION SLANTP( NORM, UPLO, DIAG, N, AP, WORK )

CHARACTER DIAG, NORM, UPLO

INTEGER   N

REAL      AP( * ), WORK( * )

```

#### PURPOSE

```       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.

```

#### DESCRIPTION

```        SLANTP returns the value
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.

```

#### ARGUMENTS

```        NORM    (input) CHARACTER*1
Specifies the value to be returned in SLANTP as described
above.

UPLO    (input) CHARACTER*1
Specifies whether the matrix A is upper or lower triangular.
= 'U':  Upper triangular
= 'L':  Lower triangular

DIAG    (input) CHARACTER*1
Specifies whether or not the matrix A is unit triangular.
= 'N':  Non-unit triangular
= 'U':  Unit triangular

N       (input) INTEGER
The order of the matrix A.  N >= 0.  When N = 0, SLANTP is
set to zero.

AP      (input) REAL 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 elements of the matrix A are
not referenced, but are assumed to be one.

WORK    (workspace) REAL array, dimension (MAX(1,LWORK)),
where LWORK >= N when NORM = 'I'; otherwise, WORK is not
referenced.

LAPACK auxiliary routine (version 3.2)     April 2011                            SLANTP(3lapack)
```