@ -20,24 +20,11 @@ from paddle import Tensor
__all__ = [
' get_window ' ,
# windows
' taylor ' ,
' hamming ' ,
' hann ' ,
' tukey ' ,
' kaiser ' ,
' gaussian ' ,
' exponential ' ,
' triang ' ,
' bohman ' ,
' blackman ' ,
' cosine ' ,
]
def _cat ( a : List [ Tensor ] , data_type : str ) - > Tensor :
l = [ paddle . to_tensor ( _ a , data_type ) for _ a in a ]
def _cat ( x : List [ Tensor ] , data_type : str ) - > Tensor :
l = [ paddle . to_tensor ( _ , data_type ) for _ in x ]
return paddle . concat ( l )
@ -48,7 +35,7 @@ def _acosh(x: Union[Tensor, float]) -> Tensor:
def _extend ( M : int , sym : bool ) - > bool :
""" Extend window by 1 sample if needed for DFT-even symmetry """
""" Extend window by 1 sample if needed for DFT-even symmetry . """
if not sym :
return M + 1 , True
else :
@ -56,7 +43,7 @@ def _extend(M: int, sym: bool) -> bool:
def _len_guards ( M : int ) - > bool :
""" Handle small or incorrect window lengths """
""" Handle small or incorrect window lengths . """
if int ( M ) != M or M < 0 :
raise ValueError ( ' Window length M must be a non-negative integer ' )
@ -64,14 +51,14 @@ def _len_guards(M: int) -> bool:
def _truncate ( w : Tensor , needed : bool ) - > Tensor :
""" Truncate window by 1 sample if needed for DFT-even symmetry """
""" Truncate window by 1 sample if needed for DFT-even symmetry . """
if needed :
return w [ : - 1 ]
else :
return w
def ( M : int , p , sig , sym : bool = True ,
def _ general_gaussian( M : int , p , sig , sym : bool = True ,
dtype : str = ' float64 ' ) - > Tensor :
""" Compute a window with a generalized Gaussian shape.
This function is consistent with scipy . signal . windows . general_gaussian ( ) .
@ -86,7 +73,7 @@ def general_gaussian(M: int, p, sig, sym: bool=True,
return _truncate ( w , needs_trunc )
def ( M : int , a : float , sym : bool = True ,
def _ general_cosine( M : int , a : float , sym : bool = True ,
dtype : str = ' float64 ' ) - > Tensor :
""" Compute a generic weighted sum of cosine terms window.
This function is consistent with scipy . signal . windows . general_cosine ( ) .
@ -101,15 +88,15 @@ def general_cosine(M: int, a: float, sym: bool=True,
return _truncate ( w , needs_trunc )
def ( M : int , alpha : float , sym : bool = True ,
def _ general_hamming( M : int , alpha : float , sym : bool = True ,
dtype : str = ' float64 ' ) - > Tensor :
""" Compute a generalized Hamming window.
This function is consistent with scipy . signal . windows . general_hamming ( )
"""
return ( M , [ alpha , 1. - alpha ] , sym , dtype = dtype )
return _ general_cosine( M , [ alpha , 1. - alpha ] , sym , dtype = dtype )
def ( M : int ,
def _ taylor( M : int ,
nbar = 4 ,
sll = 30 ,
norm = True ,
@ -118,14 +105,6 @@ def taylor(M: int,
""" Compute a Taylor window.
The Taylor window taper function approximates the Dolph - Chebyshev window ' s
constant sidelobe level for a parameterized number of near - in sidelobes .
Parameters :
M ( int ) : window size
nbar , sil , norm : the window - specific parameter .
sym ( bool ) ： whether to return symmetric window .
The default value is True
dtype ( str ) : the datatype of returned tensor .
Returns :
Tensor : the window tensor
"""
if _len_guards ( M ) :
return paddle . ones ( ( M , ) , dtype = dtype )
@ -171,46 +150,25 @@ def taylor(M: int,
return _truncate ( w , needs_trunc )
def ( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
def _ hamming( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
""" Compute a Hamming window.
The Hamming window is a taper formed by using a raised cosine with
non - zero endpoints , optimized to minimize the nearest side lobe .
Parameters :
M ( int ) : window size
sym ( bool ) ： whether to return symmetric window .
The default value is True
dtype ( str ) : the datatype of returned tensor .
Returns :
Tensor : the window tensor
"""
return ( M , 0.54 , sym , dtype = dtype )
return _general_hamming ( M , 0.54 , sym , dtype = dtype )
def ( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
def _hann ( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
""" Compute a Hann window.
The Hann window is a taper formed by using a raised cosine or sine - squared
with ends that touch zero .
Parameters :
M ( int ) : window size
sym ( bool ) ： whether to return symmetric window .
The default value is True
dtype ( str ) : the datatype of returned tensor .
Returns :
Tensor : the window tensor
"""
return ( M , 0.5 , sym , dtype = dtype )
return _general_hamming ( M , 0.5 , sym , dtype = dtype )
def ( M : int , alpha = 0.5 , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
def _tukey ( M : int , alpha = 0.5 , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
""" Compute a Tukey window.
The Tukey window is also known as a tapered cosine window .
Parameters :
M ( int ) : window size
sym ( bool ) ： whether to return symmetric window .
The default value is True
dtype ( str ) : the datatype of returned tensor .
Returns :
Tensor : the window tensor
"""
if _len_guards ( M ) :
return paddle . ones ( ( M , ) , dtype = dtype )
@ -237,32 +195,18 @@ def tukey(M: int, alpha=0.5, sym: bool=True, dtype: str='float64') -> Tensor:
return _truncate ( w , needs_trunc )
def kaiser ( M : int , beta : float , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
def _kaiser ( M : int , beta : float , sym : bool = True ,
dtype : str = ' float64 ' ) - > Tensor :
""" Compute a Kaiser window.
The Kaiser window is a taper formed by using a Bessel function .
Parameters :
M ( int ) : window size .
beta ( float ) : the window - specific parameter .
sym ( bool ) ： whether to return symmetric window .
The default value is True
Returns :
Tensor : the window tensor
"""
raise NotImplementedError ( )
def ( M : int , std : float , sym : bool = True ,
def _gaussian ( M : int , std : float , sym : bool = True ,
dtype : str = ' float64 ' ) - > Tensor :
""" Compute a Gaussian window.
The Gaussian widows has a Gaussian shape defined by the standard deviation ( std ) .
Parameters :
M ( int ) : window size .
std ( float ) : the window - specific parameter .
sym ( bool ) ： whether to return symmetric window .
The default value is True
dtype ( str ) : the datatype of returned tensor .
Returns :
Tensor : the window tensor
"""
if _len_guards ( M ) :
return paddle . ones ( ( M , ) , dtype = dtype )
@ -275,21 +219,12 @@ def gaussian(M: int, std: float, sym: bool=True,
return _truncate ( w , needs_trunc )
def ( M : int ,
def _ exponential( M : int ,
center = None ,
tau = 1. ,
sym : bool = True ,
dtype : str = ' float64 ' ) - > Tensor :
""" Compute an exponential (or Poisson) window.
Parameters :
M ( int ) : window size .
tau ( float ) : the window - specific parameter .
sym ( bool ) ： whether to return symmetric window .
The default value is True
dtype ( str ) : the datatype of returned tensor .
Returns :
Tensor : the window tensor
"""
""" Compute an exponential (or Poisson) window. """
if sym and center is not None :
raise ValueError ( " If sym==True, center must be None. " )
if _len_guards ( M ) :
@ -305,15 +240,8 @@ def exponential(M: int,
return _truncate ( w , needs_trunc )
def ( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
def _ triang( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
""" Compute a triangular window.
Parameters :
M ( int ) : window size .
sym ( bool ) ： whether to return symmetric window .
The default value is True
dtype ( str ) : the datatype of returned tensor .
Returns :
Tensor : the window tensor
"""
if _len_guards ( M ) :
return paddle . ones ( ( M , ) , dtype = dtype )
@ -330,16 +258,9 @@ def triang(M: int, sym: bool=True, dtype: str='float64') -> Tensor:
return _truncate ( w , needs_trunc )
def ( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
def _ bohman( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
""" Compute a Bohman window.
The Bohman window is the autocorrelation of a cosine window .
Parameters :
M ( int ) : window size .
sym ( bool ) ： whether to return symmetric window .
The default value is True
dtype ( str ) : the datatype of returned tensor .
Returns :
Tensor : the window tensor
"""
if _len_guards ( M ) :
return paddle . ones ( ( M , ) , dtype = dtype )
@ -353,32 +274,18 @@ def bohman(M: int, sym: bool=True, dtype: str='float64') -> Tensor:
return _truncate ( w , needs_trunc )
def ( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
def _ blackman( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
""" Compute a Blackman window.
The Blackman window is a taper formed by using the first three terms of
a summation of cosines . It was designed to have close to the minimal
leakage possible . It is close to optimal , only slightly worse than a
Kaiser window .
Parameters :
M ( int ) : window size .
sym ( bool ) ： whether to return symmetric window .
The default value is True
dtype ( str ) : the datatype of returned tensor .
Returns :
Tensor : the window tensor
"""
return ( M , [ 0.42 , 0.50 , 0.08 ] , sym , dtype = dtype )
return _general_cosine ( M , [ 0.42 , 0.50 , 0.08 ] , sym , dtype = dtype )
def ( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
def _cosine ( M : int , sym : bool = True , dtype : str = ' float64 ' ) - > Tensor :
""" Compute a window with a simple cosine shape.
Parameters :
M ( int ) : window size .
sym ( bool ) ： whether to return symmetric window .
The default value is True
dtype ( str ) : the datatype of returned tensor .
Returns :
Tensor : the window tensor
"""
if _len_guards ( M ) :
return paddle . ones ( ( M , ) , dtype = dtype )
@ -388,19 +295,20 @@ def cosine(M: int, sym: bool=True, dtype: str='float64') -> Tensor:
return _truncate ( w , needs_trunc )
## factory function
def get_window ( window : Union [ str , Tuple [ str , float ] ] ,
win_length : int ,
fftbins : bool = True ,
dtype : str = ' float64 ' ) - > Tensor :
""" Return a window of a given length and type.
Parameters :
window ( str | ( str , float ) ) : the type of window to create .
win_length ( int ) : the number of samples in the window .
fftbins ( bool ) : If True , create a " periodic " window . Otherwise ,
create a " symmetric " window , for use in filter design .
Args :
window ( Union [ str , Tuple [ str , float ] ] ) : The window function applied to the signal before the Fourier transform . Supported window functions : ' hamming ' , ' hann ' , ' kaiser ' , ' gaussian ' , ' exponential ' , ' triang ' , ' bohman ' , ' blackman ' , ' cosine ' , ' tukey ' , ' taylor ' .
win_length ( int ) : Number of samples .
fftbins ( bool , optional ) : If True , create a " periodic " window . Otherwise , create a " symmetric " window , for use in filter design . Defaults to True .
dtype ( str , optional ) : The data type of the return window . Defaults to ' float64 ' .
Returns :
The window represented as a tensor .
Tensor : The window represented as a tensor .
"""
sym = not fftbins
@ -420,7 +328,7 @@ def get_window(window: Union[str, Tuple[str, float]],
str ( type ( window ) ) )
try :
winfunc = eval ( winstr )
winfunc = eval ( ' _ ' + winstr )
except KeyError as e :
raise ValueError ( " Unknown window type. " ) from e
KP
3 years ago