besselI0¶
Evaluates the real modified Bessel function of the first kind of order zero \(I_0(x)\).
Synopsis¶
besselI0 (x)
Required Arguments¶
- float
x
(Input) - Point at which the modified Bessel function is to be evaluated.
Return Value¶
The value of the Bessel function
\[I_0(x) = \tfrac{1}{\pi} \int_0^{\pi} \cosh (x \cos \theta) d \theta\]
If no solution can be computed, NaN is returned.
Example¶
The Bessel function \(I_0(1.5)\) is evaluated.
from __future__ import print_function
from numpy import *
from pyimsl.math.besselI0 import besselI0
x = 1.5
ans = besselI0(x)
print("I0(%f) = %f" % (x, ans))
Output¶
I0(1.500000) = 1.646723
Fatal Errors¶
IMSL_LARGE_ABS_ARG_FATAL |
The absolute value of x must not be so large that \(e^{|x|}\) overflows. |