c09cb computes the inverse one-dimensional discrete wavelet transform (DWT) at a single level. The initialization method C09 Communication class constructor must be called first to set up the DWT options.

Syntax

C#
public static void c09cb(
	double[] ca,
	double[] cd,
	int n,
	double[] y,
	C09..::..C09Communications communications,
	out int ifail
)
Visual Basic
Public Shared Sub c09cb ( _
	ca As Double(), _
	cd As Double(), _
	n As Integer, _
	y As Double(), _
	communications As C09..::..C09Communications, _
	<OutAttribute> ByRef ifail As Integer _
)
Visual C++
public:
static void c09cb(
	array<double>^ ca, 
	array<double>^ cd, 
	int n, 
	array<double>^ y, 
	C09..::..C09Communications^ communications, 
	[OutAttribute] int% ifail
)
F#
static member c09cb : 
        ca : float[] * 
        cd : float[] * 
        n : int * 
        y : float[] * 
        communications : C09..::..C09Communications * 
        ifail : int byref -> unit

Parameters

ca
Type: array<System..::..Double>[]()[][]
An array of size [lenc]
On entry: the nc approximation coefficients, Ca. These will normally be the result of some transformation on the coefficients computed by c09ca.
cd
Type: array<System..::..Double>[]()[][]
An array of size [lenc]
On entry: the nc detail coefficients, Cd. These will normally be the result of some transformation on the coefficients computed by c09ca.
n
Type: System..::..Int32
On entry: n, the length of the original data array from which the wavelet coefficients were computed by c09ca and the length of the data array y that is to be reconstructed by this method.
Constraint: This must be the same as the value n passed to the initialization method c09aa.
y
Type: array<System..::..Double>[]()[][]
An array of size [n]
On exit: the reconstructed data based on approximation and detail coefficients Ca and Cd and the transform options supplied to the initialization method c09aa.
communications
Type: NagLibrary..::..C09..::..C09Communications
An Object of type C09.c09cbCommunications.
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

c09cb performs the inverse operation of c09ca. That is, given sets of nc approximation coefficients and detail coefficients, computed by c09ca using a DWT as set up by the initialization method C09 Communication class constructor, on a real data array of length n, c09cb will reconstruct the data array yi, for i=1,2,…,n, from which the coefficients were derived.

References

None.

Error Indicators and Warnings

Errors or warnings detected by the method:
ifail=1
On entry, lenc<nc, where nc is the value returned in nwc by the call to the initialization method C09 Communication class constructor.
ifail=4
On entry, n is inconsistent with the value passed to the initialization method C09 Communication class constructor.
ifail=6
On entry, the initialization method C09 Communication class constructor has not been called first or it has been called with wtrans="M", or the communication array icomm has become corrupted.
ifail=-9000
An error occured, see message report.
ifail=-1000
The array lengths are not the same for arrays
ifail=-8000
Negative dimension for array value
ifail=-6000
Invalid Parameters value

Accuracy

The accuracy of the wavelet transform depends only on the floating-point operations used in the convolution and downsampling and should thus be close to machine precision.

Parallelism and Performance

None.

Further Comments

None.

Example

See [Example] in c09ca.

See Also