Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/scipy/fft/_pocketfft/helper.py

@@ -0,0 +1,213 @@
+from numbers import Number
+import operator
+import os
+import threading
+import contextlib
+
+import numpy as np
+# good_size is exposed (and used) from this import
+from .pypocketfft import good_size
+
+_config = threading.local()
+_cpu_count = os.cpu_count()
+
+
+def _iterable_of_int(x, name=None):
+    """Convert ``x`` to an iterable sequence of int
+
+    Parameters
+    ----------
+    x : value, or sequence of values, convertible to int
+    name : str, optional
+        Name of the argument being converted, only used in the error message
+
+    Returns
+    -------
+    y : ``List[int]``
+    """
+    if isinstance(x, Number):
+        x = (x,)
+
+    try:
+        x = [operator.index(a) for a in x]
+    except TypeError as e:
+        name = name or "value"
+        raise ValueError("{} must be a scalar or iterable of integers"
+                         .format(name)) from e
+
+    return x
+
+
+def _init_nd_shape_and_axes(x, shape, axes):
+    """Handles shape and axes arguments for nd transforms"""
+    noshape = shape is None
+    noaxes = axes is None
+
+    if not noaxes:
+        axes = _iterable_of_int(axes, 'axes')
+        axes = [a + x.ndim if a < 0 else a for a in axes]
+
+        if any(a >= x.ndim or a < 0 for a in axes):
+            raise ValueError("axes exceeds dimensionality of input")
+        if len(set(axes)) != len(axes):
+            raise ValueError("all axes must be unique")
+
+    if not noshape:
+        shape = _iterable_of_int(shape, 'shape')
+
+        if axes and len(axes) != len(shape):
+            raise ValueError("when given, axes and shape arguments"
+                             " have to be of the same length")
+        if noaxes:
+            if len(shape) > x.ndim:
+                raise ValueError("shape requires more axes than are present")
+            axes = range(x.ndim - len(shape), x.ndim)
+
+        shape = [x.shape[a] if s == -1 else s for s, a in zip(shape, axes)]
+    elif noaxes:
+        shape = list(x.shape)
+        axes = range(x.ndim)
+    else:
+        shape = [x.shape[a] for a in axes]
+
+    if any(s < 1 for s in shape):
+        raise ValueError(
+            "invalid number of data points ({0}) specified".format(shape))
+
+    return shape, axes
+
+
+def _asfarray(x):
+    """
+    Convert to array with floating or complex dtype.
+
+    float16 values are also promoted to float32.
+    """
+    if not hasattr(x, "dtype"):
+        x = np.asarray(x)
+
+    if x.dtype == np.float16:
+        return np.asarray(x, np.float32)
+    elif x.dtype.kind not in 'fc':
+        return np.asarray(x, np.float64)
+
+    # Require native byte order
+    dtype = x.dtype.newbyteorder('=')
+    # Always align input
+    copy = not x.flags['ALIGNED']
+    return np.array(x, dtype=dtype, copy=copy)
+
+def _datacopied(arr, original):
+    """
+    Strict check for `arr` not sharing any data with `original`,
+    under the assumption that arr = asarray(original)
+    """
+    if arr is original:
+        return False
+    if not isinstance(original, np.ndarray) and hasattr(original, '__array__'):
+        return False
+    return arr.base is None
+
+
+def _fix_shape(x, shape, axes):
+    """Internal auxiliary function for _raw_fft, _raw_fftnd."""
+    must_copy = False
+
+    # Build an nd slice with the dimensions to be read from x
+    index = [slice(None)]*x.ndim
+    for n, ax in zip(shape, axes):
+        if x.shape[ax] >= n:
+            index[ax] = slice(0, n)
+        else:
+            index[ax] = slice(0, x.shape[ax])
+            must_copy = True
+
+    index = tuple(index)
+
+    if not must_copy:
+        return x[index], False
+
+    s = list(x.shape)
+    for n, axis in zip(shape, axes):
+        s[axis] = n
+
+    z = np.zeros(s, x.dtype)
+    z[index] = x[index]
+    return z, True
+
+
+def _fix_shape_1d(x, n, axis):
+    if n < 1:
+        raise ValueError(
+            "invalid number of data points ({0}) specified".format(n))
+
+    return _fix_shape(x, (n,), (axis,))
+
+
+def _normalization(norm, forward):
+    """Returns the pypocketfft normalization mode from the norm argument"""
+
+    if norm is None:
+        return 0 if forward else 2
+
+    if norm == 'ortho':
+        return 1
+
+    raise ValueError(
+        "Invalid norm value {}, should be None or \"ortho\".".format(norm))
+
+
+def _workers(workers):
+    if workers is None:
+        return getattr(_config, 'default_workers', 1)
+
+    if workers < 0:
+        if workers >= -_cpu_count:
+            workers += 1 + _cpu_count
+        else:
+            raise ValueError("workers value out of range; got {}, must not be"
+                             " less than {}".format(workers, -_cpu_count))
+    elif workers == 0:
+        raise ValueError("workers must not be zero")
+
+    return workers
+
+
+@contextlib.contextmanager
+def set_workers(workers):
+    """Context manager for the default number of workers used in `scipy.fft`
+
+    Parameters
+    ----------
+    workers : int
+        The default number of workers to use
+
+    Examples
+    --------
+    >>> from scipy import fft, signal
+    >>> x = np.random.randn(128, 64)
+    >>> with fft.set_workers(4):
+    ...     y = signal.fftconvolve(x, x)
+
+    """
+    old_workers = get_workers()
+    _config.default_workers = _workers(operator.index(workers))
+    try:
+        yield
+    finally:
+        _config.default_workers = old_workers
+
+
+def get_workers():
+    """Returns the default number of workers within the current context
+
+    Examples
+    --------
+    >>> from scipy import fft
+    >>> fft.get_workers()
+    1
+    >>> with fft.set_workers(4):
+    ...     fft.get_workers()
+    4
+    """
+    return getattr(_config, 'default_workers', 1)