# LinearAlgebraOperationsExtensions.SymmetricMatrixNorm<T>(ILinearAlgebraOperations<T>, MatrixNorm, MatrixTriangle, Int32, ReadOnlySpan2D<T>) Method

Returns the value of the one norm, or the Frobenius norm, or the infinity norm, or the element of largest absolute value of a real symmetric matrix A.

## Definition

Namespace: Extreme.Collections
Assembly: Extreme.Numerics (in Extreme.Numerics.dll) Version: 9.0.0
C#
``````public static T SymmetricMatrixNorm<T>(
this ILinearAlgebraOperations<T> operations,
MatrixNorm norm,
MatrixTriangle storedTriangle,
int n,
)
``````

#### Parameters

operations  ILinearAlgebraOperations<T>

norm  MatrixNorm
```            Specifies the value to be returned in DLANSY as described
above.
```
storedTriangle  MatrixTriangle
```            Specifies whether the upper or lower triangular part of the
symmetric matrix A is to be referenced.
= 'U':  Upper triangular part of A is referenced
= 'L':  Lower triangular part of A is referenced
```
n  Int32
```            The order of the matrix A.  N >= 0.  When N = 0, DLANSY is
set to zero.
```
```            Dimension (LDA,N)
The symmetric matrix A.  If UPLO = 'U', the leading n by n
upper triangular part of A contains the upper triangular part
of the matrix A, and the strictly lower triangular part of A
is not referenced.  If UPLO = 'L', the leading n by n lower
triangular part of A contains the lower triangular part of
the matrix A, and the strictly upper triangular part of A is
not referenced.
```
```            The leading dimension of the array A.  LDA >= max(N,1).
```

T

T

#### Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type ILinearAlgebraOperations<T>. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

## Remarks

```            DLANSY = ( 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'
ere  norm1  denotes the  one norm of a matrix (maximum column sum),
ormI  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.
```

This method corresponds to the LAPACK routine DLANSY.