Module « scipy.special »

Fonction spence - module scipy.special

Signature de la fonction spence

Description

spence.__doc__

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

spence(z, out=None)

Spence's function, also known as the dilogarithm.

It is defined to be

.. math::
  \int_1^z \frac{\log(t)}{1 - t}dt

for complex :math:`z`, where the contour of integration is taken
to avoid the branch cut of the logarithm. Spence's function is
analytic everywhere except the negative real axis where it has a
branch cut.

Parameters
----------
z : array_like
    Points at which to evaluate Spence's function

Returns
-------
s : ndarray
    Computed values of Spence's function

Notes
-----
There is a different convention which defines Spence's function by
the integral

.. math::
  -\int_0^z \frac{\log(1 - t)}{t}dt;

this is our ``spence(1 - z)``.