scipy.special.spence#
- scipy.special.spence(z, out=None) = <ufunc 'spence'>#
Spence’s function, also known as the dilogarithm.
It is defined to be
\[\int_1^z \frac{\log(t)}{1 - t}dt\]for complex \(z\), 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
- zarray_like
Points at which to evaluate Spence’s function
- Returns
- sndarray
Computed values of Spence’s function
Notes
There is a different convention which defines Spence’s function by the integral
\[-\int_0^z \frac{\log(1 - t)}{t}dt;\]this is our
spence(1 - z).