1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
|
.. _ref-other:
.. currentmodule:: pywt
.. include:: ../substitutions.rst
===============
Other functions
===============
Single-level n-dimensional Discrete Wavelet Transform.
------------------------------------------------------
.. function:: dwtn(data, wavelet[, mode='sym'])
Performs single-level n-dimensional Discrete Wavelet Transform.
:param data: n-dimensional array
:param wavelet: |wavelet|
:param mode: |mode|
Results are arranged in a dictionary, where key specifies
the transform type on each dimension and value is a n-dimensional
coefficients array.
For example, for a 2D case the result will look something like this::
{
'aa': <coeffs> # A(LL) - approx. on 1st dim, approx. on 2nd dim
'ad': <coeffs> # H(LH) - approx. on 1st dim, det. on 2nd dim
'da': <coeffs> # V(HL) - det. on 1st dim, approx. on 2nd dim
'dd': <coeffs> # D(HH) - det. on 1st dim, det. on 2nd dim
}
Integrating wavelet functions - :func:`intwave`
-----------------------------------------------
.. function:: intwave(wavelet[, precision=8])
Integration of wavelet function approximations as well as any other signals
can be performed using the :func:`pywt.intwave` function.
The result of the call depends on the *wavelet* argument:
* for orthogonal wavelets - an integral of the wavelet function specified
on an x-grid::
[int_psi, x] = intwave(wavelet, precision)
* for other wavelets - integrals of decomposition and reconstruction
wavelet functions and a corresponding x-grid::
[int_psi_d, int_psi_r, x] = intwave(wavelet, precision)
* for a tuple of coefficients data and a x-grid - an integral of function
and the given x-grid is returned (the x-grid is used for computations).::
[int_function, x] = intwave((data, x), precision)
**Example:**
.. sourcecode:: python
>>> import pywt
>>> wavelet1 = pywt.Wavelet('db2')
>>> [int_psi, x] = pywt.intwave(wavelet1, precision=5)
>>> wavelet2 = pywt.Wavelet('bior1.3')
>>> [int_psi_d, int_psi_r, x] = pywt.intwave(wavelet2, precision=5)
Central frequency of *psi* wavelet function
-------------------------------------------
.. function:: centfrq(wavelet[, precision=8])
centfrq((function_approx, x))
:param wavelet: :class:`Wavelet`, wavelet name string or
`(wavelet function approx., x grid)` pair
:param precision: Precision that will be used for wavelet function
approximation computed with the :meth:`Wavelet.wavefun`
method.
|
