|
NAG[f16ufc] NAG[nag_zsy_norm] - -norm, -norm, Frobenius norm, largest absolute element, complex symmetric matrix
|
|
Calling Sequence
f16ufc(norm_type, uplo, a, r, 'n'=n, 'fail'=fail)
nag_zsy_norm(. . .)
Parameters
|
norm_type - String;
|
|
|
On entry: specifies the value to be returned.
|
|
or "Nag_OneNorm" The 1-norm.
|
|
The -norm.
|
|
The Frobenius (or Euclidean) norm.
|
|
The value (not a norm).
|
|
Constraint: "Nag_OneNorm", "Nag_InfNorm", "Nag_FrobeniusNorm" or "Nag_MaxNorm". .
|
|
|
uplo - String;
|
|
|
On entry: specifies whether the upper or lower triangular part of is stored.
|
|
The upper triangular part of is stored.
|
|
The lower triangular part of is stored.
|
|
Constraint: "Nag_Upper" or "Nag_Lower". .
|
|
|
a - Matrix(1..dim1, 1..dim2, datatype=complex[8], order=order);
|
|
|
Note: this array may be supplied in Fortran_order or C_order , as specified by order. All array parameters must use a consistent order.
|
|
If , the upper triangle of must be stored and the elements of the array below the diagonal are not referenced.
|
|
If , the lower triangle of must be stored and the elements of the array above the diagonal are not referenced.
|
|
|
r - assignable;
|
|
|
Note: On exit the variable r will have a value of type float.
|
|
On exit: the value of the norm specified by norm.
|
|
|
'n'=n - integer; (optional)
|
|
|
Default value: the dimension of the array a.
|
|
On entry: , the order of the matrix .
|
|
Constraint: . .
|
|
|
'fail'=fail - table; (optional)
|
|
|
The NAG error argument, see the documentation for NagError.
|
|
|
|
Description
|
|
|
Purpose
|
|
nag_zsy_norm (f16ufc) calculates the value of the 1-norm, the -norm, the Frobenius norm or the maximum absolute value of the elements of a complex by symmetric matrix.
|
|
Description
|
|
Given a complex by symmetric matrix, , nag_zsy_norm (f16ufc) calculates one of the values given by
or
Note that, since is symmetric, .
|
|
Error Indicators and Warnings
|
|
"NE_ALLOC_FAIL"
Dynamic memory allocation failed.
"NE_BAD_PARAM"
On entry, argument had an illegal value.
"NE_INT"
On entry, . Constraint: .
|
|
Accuracy
|
|
The BLAS standard requires accurate implementations which avoid unnecessary over/underflow (see Section 2.7 of The BLAS Technical Forum Standard (2001)).
|
|
|
Examples
|
|
>
|
norm_type := "Nag_OneNorm":
uplo := "Nag_Lower":
n := 4:
a := Matrix([[-0.39 -0.71*I , 0 +0*I , 0 +0*I , 0 +0*I ], [5.14 -0.64*I , 8.859999999999999 +1.81*I , 0 +0*I , 0 +0*I ], [-7.86 -2.96*I , -3.52 +0.58*I , -2.83 -0.03*I , 0 +0*I ], [3.8 +0.92*I , 5.32 -1.59*I , -1.54 -2.86*I , -0.5600000000000001 +0.12*I ]], datatype=complex[8]):
NAG:-f16ufc(norm_type, uplo, a, r, 'n' = n):
|
|
|