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Module « scipy.special »

Fonction i1e - module scipy.special

Signature de la fonction i1e

def i1e(*args, **kwargs) 

Description

help(scipy.special.i1e)

i1e(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature])


    i1e(x, out=None)

    Exponentially scaled modified Bessel function of order 1.

    Defined as::

        i1e(x) = exp(-abs(x)) * i1(x)

    Parameters
    ----------
    x : array_like
        Argument (float)
    out : ndarray, optional
        Optional output array for the function values

    Returns
    -------
    I : scalar or ndarray
        Value of the exponentially scaled modified Bessel function of order 1
        at `x`.

    See Also
    --------
    iv: Modified Bessel function of the first kind
    i1: Modified Bessel function of order 1

    Notes
    -----
    The range is partitioned into the two intervals [0, 8] and (8, infinity).
    Chebyshev polynomial expansions are employed in each interval. The
    polynomial expansions used are the same as those in `i1`, but
    they are not multiplied by the dominant exponential factor.

    This function is a wrapper for the Cephes [1]_ routine `i1e`. `i1e`
    is useful for large arguments `x`: for these, `i1` quickly overflows.

    References
    ----------
    .. [1] Cephes Mathematical Functions Library,
           http://www.netlib.org/cephes/

    Examples
    --------
    In the following example `i1` returns infinity whereas `i1e` still returns
    a finite number.

    >>> from scipy.special import i1, i1e
    >>> i1(1000.), i1e(1000.)
    (inf, 0.01261093025692863)

    Calculate the function at several points by providing a NumPy array or
    list for `x`:

    >>> import numpy as np
    >>> i1e(np.array([-2., 0., 6.]))
    array([-0.21526929,  0.        ,  0.15205146])

    Plot the function between -10 and 10.

    >>> import matplotlib.pyplot as plt
    >>> fig, ax = plt.subplots()
    >>> x = np.linspace(-10., 10., 1000)
    >>> y = i1e(x)
    >>> ax.plot(x, y)
    >>> plt.show()
    

Vous êtes un professionnel et vous avez besoin d'une formation ? Programmation Python
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