c06gb forms the complex conjugate of a Hermitian sequence of n data values.

Syntax

C#
public static void c06gb(
	double[] x,
	int n,
	out int ifail
)
Visual Basic
Public Shared Sub c06gb ( _
	x As Double(), _
	n As Integer, _
	<OutAttribute> ByRef ifail As Integer _
)
Visual C++
public:
static void c06gb(
	array<double>^ x, 
	int n, 
	[OutAttribute] int% ifail
)
F#
static member c06gb : 
        x : float[] * 
        n : int * 
        ifail : int byref -> unit

Parameters

x
Type: array<System..::..Double>[]()[][]
An array of size [n]
On entry: if the data values zj are written as xj+iyj and if x is declared with bounds 0:n-1 in the method from which c06gb is called, then for 0≤j≤n/2, x[j-1] must contain xj (=xn-j), while for n/2<j≤n-1, x[j-1] must contain -yj (=yn-j). In other words, x must contain the Hermitian sequence in Hermitian form. (See also [] in the C06 class Chapter Introduction.)
On exit: the imaginary parts yj are negated. The real parts xj are not referenced.
n
Type: System..::..Int32
On entry: n, the number of data values.
Constraint: n≥1.
ifail
Type: System..::..Int32%
On exit: ifail=0 unless the method detects an error or a warning has been flagged (see [Error Indicators and Warnings]).

Description

This is a utility method for use in conjunction with c06ea c06eb (C06FAF not in this release) (C06FBF not in this release) to calculate inverse discrete Fourier transforms (see the C06 class).

References

None.

Error Indicators and Warnings

Errors or warnings detected by the method:
ifail=1
On entry,n<1.
ifail=-9000
An error occured, see message report.
ifail=-8000
Negative dimension for array value
ifail=-6000
Invalid Parameters value

Accuracy

Exact.

Parallelism and Performance

None.

Further Comments

The time taken by c06gb is negligible.

Example

See Also