scipy.special.lmbda(v, x)[source]

Jahnke-Emden Lambda function, Lambdav(x).

This function is defined as [R483],

\[\Lambda_v(x) = \Gamma(v+1) \frac{J_v(x)}{(x/2)^v},\]

where \(\Gamma\) is the gamma function and \(J_v\) is the Bessel function of the first kind.


v : float

Order of the Lambda function

x : float

Value at which to evaluate the function and derivatives


vl : ndarray

Values of Lambda_vi(x), for vi=v-int(v), vi=1+v-int(v), ..., vi=v.

dl : ndarray

Derivatives Lambda_vi’(x), for vi=v-int(v), vi=1+v-int(v), ..., vi=v.


[R482]Zhang, Shanjie and Jin, Jianming. “Computation of Special Functions”, John Wiley and Sons, 1996.
[R483](1, 2) Jahnke, E. and Emde, F. “Tables of Functions with Formulae and Curves” (4th ed.), Dover, 1945