General Functions
=================

.. currentmodule:: pyvoimooo

.. attribute:: eps

    Return the machine epsilon, that is, the difference between 1.0 and the next value representable by the default floating-point type used in the underlying C++ implementation.

.. attribute:: sizeoffloat

    The size of the default float type of Voimooo [number of bytes]

.. attribute:: pi

    The value of :math:`\pi`.

    This attribute is provided to reflect the actual value used in the underlying C++ implementation.

.. attribute:: pi2

    Twice the value of :math:`\pi`.

    This attribute is provided to reflect the actual value used in the underlying C++ implementation.


.. function:: lin2db(v)

    :arg v: Input value on linear scale.

    :return: the value on a decibel [dB] scale.

    :class:`lin2dbd` provides the same for 64b float values.

    .. versionadded:: 0.8.9

.. function:: db2lin(v)

    :arg v: Input value on decibel scale.

    :return: the value on a linear scale.

    :class:`db2lind` provides the same for 64b float values.

    .. versionadded:: 0.8.9

.. function:: hz2cent(v)

    :arg v: Input value on linear hertz scale.

    :return: the value on a cent scale (relative to 440Hz).

    .. versionadded:: 0.8.9

.. function:: cent2hz(v)

    :arg v: Input value on cent scale (relative to 440Hz).

    :return: the value on a linear hertz scale.

    .. versionadded:: 0.8.9

.. function:: cent2freqratio(v)

    :arg v: Input value on cent scale.

    :return: the value as a linear coefficient.

    .. versionadded:: 0.10.1

.. function:: freqratio2cent(v)

    :arg v: A linear coefficient.

    :return: the value on cent scale.

    .. versionadded:: 0.10.1


.. function:: dftlen_from_over_sampling_factor(winlen, osf)

    :arg winlen: A window length.
    :type winlen: int

    :arg osf: An over-sampling factor.
    :type osf: int

    :return: The power-2 **dftlen**, based on a given :attr:`winlen` and an over-sampling factor :attr:`osf`.

    .. versionadded:: 0.8.9



.. attribute:: libversion

    Return the version of the Voimooo library that is wrapped by this Python wrapper.
    Identical to `__version__`.

    .. versionadded:: 0.8.9

.. attribute:: compile_info

    Report some compile-time information in a string.

    .. versionadded:: 0.8.9

.. attribute:: user_name

    The user name, as obtained by Voimooo through the operating system.

    .. versionadded:: 0.10.1

.. attribute:: user_id

    The user id, which is the MD5 of the `user_name`.

    .. versionadded:: 0.10.1