SciPy

scipy.special.modstruve

scipy.special.modstruve(v, x) = <ufunc 'modstruve'>

Modified Struve function.

Return the value of the modified Struve function of order v at x. The modified Struve function is defined as,

\[L_v(x) = -\imath \exp(-\pi\imath v/2) H_v(x),\]

where \(H_v\) is the Struve function.

Parameters:

v : array_like

Order of the modified Struve function (float).

x : array_like

Argument of the Struve function (float; must be positive unless v is an integer).

Returns:

L : ndarray

Value of the modified Struve function of order v at x.

See also

struve

Notes

Three methods discussed in [R493] are used to evaluate the function:

  • power series
  • expansion in Bessel functions (if \(|z| < |v| + 20\))
  • asymptotic large-z expansion (if \(z \geq 0.7v + 12\))

Rounding errors are estimated based on the largest terms in the sums, and the result associated with the smallest error is returned.

References

[R493](1, 2) NIST Digital Library of Mathematical Functions http://dlmf.nist.gov/11

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