naginterfaces.library.wav.dim1_​multi_​inv

naginterfaces.library.wav.dim1_multi_inv(nwlinv, c, n, comm)[source]

dim1_multi_inv computes the inverse one-dimensional multi-level discrete wavelet transform (DWT). This function reconstructs data from (possibly filtered or otherwise manipulated) wavelet transform coefficients calculated by dim1_multi_fwd() from an original set of data. The initialization function dim1_init() must be called first to set up the DWT options.

For full information please refer to the NAG Library document for c09cd

https://www.nag.com/numeric/nl/nagdoc_30/flhtml/c09/c09cdf.html

Parameters
nwlinvint

The number of levels to be used in the inverse multi-level transform. The number of levels must be less than or equal to , which has the value of argument as used in the computation of the wavelet coefficients using dim1_multi_fwd(). The data will be reconstructed to level , where level is the original input dataset provided to dim1_multi_fwd().

cfloat, array-like, shape

The coefficients of a multi-level wavelet transform of the dataset.

Let be the number of coefficients (of each type) at level , for .

Then, setting and , for , the coefficients are stored in as follows:

, for

Contains the level approximation coefficients, .

, for

Contains the level detail coefficients .

, for

Contains the level detail coefficients, for .

The values , for , are contained in which is produced as output by a preceding call to dim1_multi_fwd().

See dim1_multi_fwd() for details.

nint

, the length of the data array, , to be reconstructed. For a full reconstruction of levels, where is as supplied to dim1_multi_fwd(), this must be the same as argument used in the call to dim1_multi_fwd(). For a partial reconstruction of , this must be equal to , as returned from dim1_multi_fwd().

commdict, communication object

Communication structure.

This argument must have been initialized by a prior call to dim1_init().

Returns
yfloat, ndarray, shape

The dataset reconstructed from the multi-level wavelet transform coefficients and the transformation options supplied to the initialization function dim1_init().

Raises
NagValueError
(errno )

On entry, is larger than the number of levels computed by the preceding call to dim1_multi_fwd(): , expected .

(errno )

On entry, .

Constraint: .

(errno )

On entry, is set too small: .

Constraint: .

(errno )

On entry, is inconsistent with the value passed to the initialization function: , should be .

(errno )

Either the initialization function has not been called first or array [‘icomm’] has been corrupted.

(errno )

Either the initialization function was called with or array [‘icomm’] has been corrupted.

Notes

dim1_multi_inv performs the inverse operation of dim1_multi_fwd(). That is, given a set of wavelet coefficients, computed up to level by dim1_multi_fwd() using a DWT as set up by the initialization function dim1_init(), on a real data array of length , dim1_multi_inv will reconstruct the data array , for , from which the coefficients were derived. If the original input dataset is level , then it is possible to terminate reconstruction at a higher level by specifying fewer than the number of levels used in the call to dim1_multi_fwd(). This results in a partial reconstruction.