This is documentation for an old release of SciPy (version 0.18.1). Read this page in the documentation of the latest stable release (version 1.15.1).
scipy.special.i1¶
- scipy.special.i1(x) = <ufunc 'i1'>¶
Modified Bessel function of order 1.
Defined as,
I1(x)=12x∞∑k=0(x2/4)kk!(k+1)!=−ıJ1(ıx),where J1 is the Bessel function of the first kind of order 1.
Parameters: x : array_like
Argument (float)
Returns: I : ndarray
Value of the modified Bessel function of order 1 at x.
Notes
The range is partitioned into the two intervals [0, 8] and (8, infinity). Chebyshev polynomial expansions are employed in each interval.
This function is a wrapper for the Cephes [R381] routine i1.
References
[R381] (1, 2) Cephes Mathematical Functions Library, http://www.netlib.org/cephes/index.html