scipy.special.sici¶
-
scipy.special.
sici
(x, out=None) = <ufunc 'sici'>¶ Sine and cosine integrals.
The sine integral is
\[\int_0^x \frac{\sin{t}}{t}dt\]and the cosine integral is
\[\gamma + \log(x) + \int_0^x \frac{\cos{t} - 1}{t}dt\]where \(\gamma\) is Euler’s constant and \(\log\) is the principle branch of the logarithm.
- Parameters
- xarray_like
Real or complex points at which to compute the sine and cosine integrals.
- Returns
- sindarray
Sine integral at
x
- cindarray
Cosine integral at
x
Notes
For real arguments with
x < 0
,ci
is the real part of the cosine integral. For such pointsci(x)
andci(x + 0j)
differ by a factor of1j*pi
.For real arguments the function is computed by calling Cephes’ [1] sici routine. For complex arguments the algorithm is based on Mpmath’s [2] si and ci routines.
References
- 1
Cephes Mathematical Functions Library, http://www.netlib.org/cephes/
- 2
Fredrik Johansson and others. “mpmath: a Python library for arbitrary-precision floating-point arithmetic” (Version 0.19) http://mpmath.org/